228 FXUS61 KCLE 181800 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 200 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... Trended high temperatures up a degree or two for today and Tuesday in central and eastern portions of the area. The Marginal Risk for Severe Thunderstorms has been expanded across northern Ohio into Northwest Pennsylvania for this evening. && .KEY MESSAGES... 1) The hottest temperatures of the year arrive today and continue on Tuesday. The heat will break behind a cold front on Wednesday with below normal temperatures continuing into Thursday. 2) A few strong to severe thunderstorms are possible in Northwest Ohio and across the northern counties this afternoon and evening. The potential for severe thunderstorms returns on Tuesday afternoon with greater coverage of storms expected. Damaging wind gusts to 60 mph and hail are the primary concerns with severe thunderstorms. 3) Unsettled conditions are expected heading into the holiday weekend. && .DISCUSSION... KEY MESSAGE 1... The local area resides in the warm sector today with a ridge over the Appalachians and 500mb heights of 585dm. A southwesterly pressure gradient supports warm advection with 925mb temperatures reaching 24-25C. Winds are expected to gust to 20-25 mph in the east and up to 30 mph in the west which will help to mix out dewpoints and keep humidity/heat index values in check. The high temperature forecast was raised by 1-3 degrees from north central Ohio into Northwest Pennsylvania for this afternoon with highs expected in the upper 80s to near 90 degrees and heat index values only running about a degree higher. With that said, this is the first near 90 degree day of the season and people will likely feel the effects of heat more easily. Several climate sites are forecast to be within a degree or two of record values(see the climate section below). The temperature forecast for Tuesday is a little more tricky as we have to contend with increasing cloud cover and higher chances of precipitation during the afternoon. Dewpoints also trend up closer to the mid 60s so humidity will be more noticeable. Due to the increasing clouds and moisture, temperatures will likely top out a couple degrees lower than Monday but heat index will be virtually the same. The brief bout of near record highs will abruptly end on Wednesday behind a strong cold front. 850mb temperatures fall by 11-12C in 24 hours with a northwesterly flow off the lake. High temperatures are forecast to be 20-25 degrees cooler by Wednesday and remain cool on Thursday. Temperatures do gradually trend warmer heading into the holiday weekend but will be impacted by chances for precipitation. KEY MESSAGE 2... Convection is ongoing this morning from the Upper Peninsula of Michigan extending southwest to Iowa ahead of low pressure located over western Wisconsin. A moist and unstable airmass advances eastward into the Central Great Lakes today as the trough over the Great Basin shifts east into the Plains states. Leading shortwave energy across northern Wisconsin tends to weaken while another shortwave is expected to move across Indiana and western Ohio later today. While we start the day capped, mixed layer CAPE of 800-1100 may sneak into northwest Ohio late this afternoon ahead of the shortwave which comes with increasing shear values. The better lift skirts Lake Erie and the lakeshore counties into this evening and may have to monitor for a few stronger storms moving east from Toledo towards Erie in the 4-9 PM window. While activity is generally expected to dissipate for the overnight hours, a moist and weakly unstable airmass resides overhead tonight so kept a low pop in the forecast through Tuesday morning. On Tuesday surface low pressure is forecast tomove northeast across Lake Superior with a cold front extending south through the Central Great Lakes. A pre-frontal trough with moderate instability moves into NW Ohio during the afternoon on Tuesday. Expecting good coverage of showers and thunderstorms to develop west of the I-71 corridor during the afternoon with around 2000 J/kg of ML CAPE and 20-30 knots of bulk shear. Thunderstorms will continue eastward through the evening. This looks to present a scattered wind and hail threat for Tuesday afternoon and evening from about 2-10 PM. Storm relative helicity values are slightly higher in the northeast with good veering of the flow with height and the Storm Prediction Center has included a low end tornado threat for that area. Rain will linger along the cold front Tuesday night into early Wednesday with a drying trend through the day on Wednesday as broad high pressure expands south of Lake Erie. KEY MESSAGE 3... Confidence in pattern evolution is low heading into the upcoming holiday weekend. Models depict southwesterly flow and moisture advection later Friday into Saturday ahead of a trough approaching from the Plains and a ridge along the East Coast. This will likely result in an unsettled pattern with periods of showers and thunderstorms. Timing is difficult this far out but could see the first round of precipitation Friday night into Saturday then additional precipitation possible later in the day on Sunday. && .AVIATION /18Z Monday THROUGH Saturday/... All eyes will be on the line of convection currently marching through Indiana as of 1730Z. Expect this to move into northwest OH over the next few hours with strong storms expected and gusts at the TOL/FDY terminals, but then should weaken fairly rapidly as it continues eastward. Will include TSRA at CLE and MFD as this line of convection deteriorates, but not any further eastward. Winds southwesterly will gust to 30kts. May ease a bit overnight, and at TOL/FDY where the low level jet is more pronounced, LLWS possible tonight. Southwesterly winds gusting to 30kts continues again Tuesday, and expect another round of convection to develop, but affects for our area will lie just beyond the forecast period/18Z Tuesday. Outlook...Non-VFR likely at times in showers/thunderstorms Tuesday into Wednesday. Non-VFR possible in showers on Friday. && .MARINE... South winds are slightly elevated at 10-15kt early this morning and will continue today. Gusts up to 25kt are possible in the nearshore waters west of Cleveland this afternoon. Thunderstorms may reach western Lake Erie this evening, and could pack brief wind gusts over 35kt before dissipating while tracking east. Otherwise, southerly winds will remain slightly elevated at 10-15kt tonight into Tuesday. Winds increase a bit further to 15-20kt Tuesday afternoon, with gusts potentially up to 30kt in the nearshore waters west of Cleveland. Small craft headlines remain possible for Tuesday. There is additional thunderstorm potential spreading from west to east Tuesday afternoon and evening along and ahead of a cold front, again with potential for storms over the lake to pack strong wind gusts over 35kt. Winds whip around to the north late Tuesday night into Wednesday behind the cold front, and gradually shift more northeasterly Wednesday into Thursday and more easterly for Friday. These winds are currently forecast to be around 15kt which would bring choppiness, but there is a chance winds trend up closer to 20kt Thursday into Friday, which could warrant some small craft/beach hazards headlines. && .CLIMATE... High temperatures today and Tuesday will approach record values. The following are the records for May 18 and 19 at local climate sites. Date Toledo Mansfield Cleveland Akron Youngstown Erie05-18 95(1962) 92(1962) 91(1962) 92(1962) 92(1962) 89(1889) 05-19 92(1996) 88(1964) 88(1998) 91(1911) 89(1934) 90(1996) && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...None. && $$ DISCUSSION...10 AVIATION...26 MARINE...Sullivan  391 FXUS63 KFSD 181801 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 101 PM CDT Mon May 18 2026 .KEY MESSAGES... - Showers and isolated thunderstorms return to the area this afternoon this evening into tonight. - A few storms along and southeast of a Wayne to Sheldon to Windom line may be strong to severe late this afternoon into this evening. The main threat would be hail to half dollar size but storms this strong should remain very isolated and likely closer to near and east of Highway 60. - Areas of frost or freeze will be possible on Wednesday morning, with the better chances north of I-90. - Cool conditions prevail this week. Dry weather expected mid week. Another round of storms is possible Thursday through Friday. && .DISCUSSION... Issued at 1258 PM CDT Mon May 18 2026 Early this afternoon the surface to 925 mb front was across southern NE into southern IA. Given the marginal strength of the incoming wave, this boundary should not lift far enough north and west by late afternoon to get into the area. This should limit any wind and tornado threats and keep them off to the southeast. However, some elevated hailers will remain possible across mainly northwest IA as elevated CAPE values ramp up to about 1000-1500 J/KG and deep layer shear is a fairly strong, unidirectional 40-50 knots. This would be lifting a parcel from above the stratus layer, which would likely be in about the 800-750mb layer. The better chances will be from about 5 pm to 9 pm. After this wave pushes the remaining instability out of the area this evening, dry and cool conditions are expected for Tuesday and Wednesday. The only concerns on these two days will be the potential for frost and freeze conditions, mostly north of I-90, as surface high pressure is in place. Another weaker wave moves through the area on Wednesday but for now this appears to bring mainly mid level cloud cover. The next better chance for showers and thunderstorms will come Thursday night into Friday night. At this time severe weather looks to remain isolated as model instability fields are hinting at 1000 J/kg CAPE or less for the most part. Once this wave passes a warming trend should move in as flat ridging aloft develops ahead of a deepening low pressure in the Northern Rockies. Saturday should be mild, likely in the 70s, while Sunday sees the better chance to warm into the 80s. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1243 PM CDT Mon May 18 2026 Widespread stratus, mai.nly IFR but occasionally MVFR, will persist through much of the night, but gradually improve later tonight into Tuesday morning. Scattered showers and isolated thunderstorms will increase in coverage through the afternoon into the early evening, then gradually diminish through the early overnight hours. The strongest thunderstorms will be in parts of northwest IA, with the better chance from 5 pm through 9 pm. A few of these storms could contain hail. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...08 AVIATION...08  259 FXUS64 KEWX 181800 AAA AFDEWX Area Forecast Discussion...UPDATED National Weather Service Austin/San Antonio TX 100 PM CDT Mon May 18 2026 ...New AVIATION... .KEY MESSAGES... - Low chance for a few showers and storms today. - Active weather pattern from mid-week through the upcoming Memorial Holiday weekend. Heavy rain at times could lead to localized flooding. && .SHORT TERM... (Today through Tuesday) Issued at 124 AM CDT Mon May 18 2026 Today will be another warm and muggy day under mostly cloudy to perhaps partly cloudy skies as moisture remains strewn across the area. Highs should generally top out in the low 90s north and upper 90s south. We should see more peaks of sun than we did on Sunday which in turn will give us heat indices or "feels like" temps close to 100 for many areas with heat indices above 105 possible across the Winter Garden and Rio Grande Plains. We also should have a stronger cap in place today but it's possible we could see a storm try to break it mainly in the late afternoon/evening, if it does we could see a burst of heavy rainfall along with the potential for small hail and gusty winds. If any activity does form it should wane significantly after sunset with the loss of daytime heating. Tuesday should be another warm and very muggy day as we remain entrenched underneath this southwest flow aloft and southerly flow at the surface. A cold front located to our north will be on its way southward while a dryline located over northern Mexico and West TX will also be advancing eastward throughout the day. Both of these features should be the next focus for our next round of convection and heavy rainfall potential. This would likely commence late Tuesday afternoon and continue through the evening, more on that below. && .LONG TERM... (Tuesday night through Sunday) Issued at 124 AM CDT Mon May 18 2026 A big pattern change is forecasted for the long term as we remain under southwest flow aloft which usually allows for disturbances to impact our area and take advantage of the rich moisture and unstable air in place. As such, it seems likely that multiple disturbances could impact our area as a dryline will be situated just off to our west across west TX and will have advanced eastward through the day Tuesday before beginning its daily retreat back westward. Similarly, the previous mentioned cold front will be advancing southward and as it does so numerous Hi-res models and ensembles suggest that convection would blossom along and ahead of this front by Tuesday evening. Most models highlight areas to our north across central TX where discrete supercells would initially be possible before quickly congealing into a line and working its way southeastward towards our area. What's interesting to note is just how consistent all of these models continue to be at targeting this scenario. As this convection moves closer we could see a secondary line of storms form out west from the aforementioned dryline convection if it forms over northern Mexico. Depending on how robust this activity becomes will determine how far eastward it advances. SPC currently has most of the area in a level 1 or 2 of 5 risk for severe weather for this time period. With the continued moisture remaining across the area any convection that does form will be capable of very heavy rainfall. Eventually this front becomes stationary towards the middle of the week and washes out somewhere across our area. This now stationary front will be the continued focus for additional shower and thunderstorm activity throughout the period as we remain entrenched in a very moist airmass with continued southwest flow aloft. The main forecast challenge in the coming days will be identifying which features will provide the strongest focus forstorms each day. The pattern transitions from a dryline/shortwave-driven severe weather pattern late Tuesday to a frontal and eventually a surface boundary-driven heavy rain and storm regime later in the week. Global models continue to hint at this pattern continuing into and even beyond next weekend as disturbances aloft continue to ride over our area and ignite the potential for additional rounds of showers and thunderstorms. While most of the rain will be beneficial for many areas, there are some beginning signs that we could see heavier rounds that may lead to localized flooding concerns. However due to the difficult timing and placement of these additional rounds and the numerous surface and outflow boundaries from previous convection it's still too hard to decipher which areas may see heavier amounts and when. Bottom line is an active and wet pattern looks likely for the entire area starting early next week. Continue to check back as details continue to get clearer over the coming days. && .AVIATION... (18Z TAFS) Issued at 1249 PM CDT Mon May 18 2026 Cigs are either MVFR or will trend to MVFR within the hour at area TAF sites. Otherwise, some isolated convection may develop near DRT late this afternoon or early evening. With coverage limited, we will not mention any convection in the forecast at this time. Low clouds and MVFR cigs will return by mid-evening along I-35, with DRT seeing these cigs closer to 09Z. Gusty south to southeast winds will persist through the period. We will need to monitor for a line of convection approaching AUS near or just beyond the end of the current 30 hour forecast period. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 77 90 71 85 / 10 30 80 60 Austin Bergstrom Intl Airport 79 90 71 85 / 10 30 70 60 New Braunfels Muni Airport 77 90 70 85 / 10 20 70 60 Burnet Muni Airport 75 86 67 82 / 10 40 80 60 Del Rio Intl Airport 76 93 71 88 / 20 20 50 40 Georgetown Muni Airport 77 88 69 83 / 10 40 80 60 Hondo Muni Airport 78 90 70 84 / 10 20 70 60 San Marcos Muni Airport 78 91 71 85 / 10 20 70 60 La Grange - Fayette Regional 78 90 72 85 / 10 20 70 60 San Antonio Intl Airport 78 91 71 85 / 10 20 70 60 Stinson Muni Airport 79 92 71 86 / 10 10 70 60 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Tran LONG TERM....Tran AVIATION...Platt  389 FXUS65 KBOU 181801 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 1201 PM MDT Mon May 18 2026 .KEY MESSAGES... - Rain and mountain/foothill snow increases in coverage this morning with much colder temperatures arriving. - Accumulating snow for the mountains and the foothills. Only a few wet snowflakes possibly mixed in for the I-25 Corridor. - One last spring freeze possible on some of the plains Monday night. - Delay in the warming and drying trend for the week ahead, but still warmer and drier by Friday - next weekend. && .UPDATE... Issued at 933 AM MDT Mon May 18 2026 Snow was increasing over the mountains, with a heavy accumulating drizzle along the Front Range I-25 Corridor. Precipitation rates will increase as expected this morning through mid afternoon with the heart of QG forcing and band of heavier precipitation on the western slope moving in. It was thinning a bit as it moves this way, but still expect a 2-3 hour period of enhanced precipitation rates and even a possibility of a couple thunderstorms as this moves in. Given snow levels are lower already (down to about 6500-7000 feet in Larimer County), we added a Winter Weather Advisory for the northern Foothills as snow intensity should pick up to >1" per hour. Also there was even a narrow corridor of freezing drizzle in the higher foothills of Boulder County (7,500-8,500 feet) where deeper seeder/feeder action was not in play yet. That will change soon as deeper moisture arrives. We also added North Park to the Winter Weather Advisory considering heavier snow had begun falling there this morning and will continue through mid afternoon with rates 1" per hour or more at times. Finally, still can't rule out a few snowflakes mixing in with our rain in the I-25 Urban Corridor despite high surface wet bulb temps. Main opportunity would be with convective showers early to mid afternoon, and then into evening if precipitation lingers long enough under the influence of further cold advection aloft. && .DISCUSSION /Through Sunday/... Issued at 1222 AM MDT Mon May 18 2026 An upper level trough over the Great Basin will move across the area on Mon with favorable mid level ascent thru the aftn hours. At the sfc, upslope flow will be in place which will combine with the upper level trough to produce widespread precip across the area. Snow will occur in the mtns and higher foothills with several inches of accumulation. Have upgraded areas north of I-70 in the mtns to a warning as east facing slopes could see from 12 to 18 inches in some areas. Elsewhere will keep amounts in the advisory range. In the foothills, some of the higher areas may see 4 to 8 inches above 8000 ft with lessor amounts below 8000 ft. By Mon night precip should gradually decrease over the area during the evening hours. Overnight lows late Mon night into early Tue morning may drop down to freezing or slightly below across portions of the plains. For Tue, a disturbance will move across the area late in the aftn thru Tue night. As this feature moves across, there will be another round of precip over the higher terrain and across portions of the plains. Highs on Tue will remain cool as readings stay in the 50's across the plains. Looking ahead to Wed, an unsettled pattern will continue as decent lapse rates will combine with lingering moisture to produce a good chc of showers and thunderstorms over the higher terrain and portions of the plains. Most of the activity will occur in the late aftn and early evening hours. Highs will remain below normal as readings only reach the upper 50's to mid 60's across the plains. By Thu into Fri, latest data shows another upper level trough moving southeast towards the area. Not sure about the timing ofthis system, however, as it moves across should see another good chance of showers and thunderstorms. Temperatures both days will be in the mid 60's to lower 70's across the plains. For next weekend, will see a return to a drier and warmer pattern based on latest data. && .AVIATION /18Z TAFS through 18Z Tuesday/... Issued at 1159 AM MDT Mon May 18 2026 Model cross sections indicate that the ceiling should be at or below BKN-OVC015 at DIA the rest of the today and all of tonight. Will leave a PROB30 in for TSRA this afternoon for 3 or 4 hours based on the instability available. Visiblities should range from 1SM-5SM, lower with the better rain showers through around 00Z this afternoon. Will get visibilities to P6SM after that. There could be patchy fog developing after 06Z tonight, but there is enough uncertainty at this time so I will it out for now. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 9 PM MDT this evening for COZ030- 031-034-035. Winter Storm Warning until 9 PM MDT this evening for COZ033. Frost Advisory from midnight tonight to 8 AM MDT Tuesday for COZ038-042>051. Freeze Warning from midnight tonight to 8 AM MDT Tuesday for COZ041. && $$ UPDATE...20 DISCUSSION...RPK AVIATION...66  422 FXUS61 KILN 181801 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 201 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... Continued to tweak Monday/Tuesday temperatures slightly downward from blended solution. Increased precip/thunderstorm chances for Tuesday afternoon from blended solutions, with only slight change from previous forecast. && .KEY MESSAGES... 1) Above normal temperatures persist through Tuesday. A cold front approaches the Ohio Valley on Tuesday, bringing a chance for strong to severe storms, followed by cooler temperatures behind the front for mid to late week. 2) Some potential for strong to severe storms in far NW forecast area this afternoon, with a greater chance of strong to severe storms possible Tuesday afternoon and Tuesday night. && .DISCUSSION... KEY MESSAGE 1) A period of well above normal temperatures will persist through Tuesday ahead of a cold front that passes through the area late Tuesday night. For today and Tuesday, high temperatures range from the mid-upper 80s to around 90. Temperatures on Wednesday are mitigated in the wake of the front, along with any showers and thunderstorms. Highs are expected to range from near 70 northwest to around 80 southeast. Temperatures cool behind the passage of the front Wednesday, lingering into Thursday. Temperatures climb back to above normal Friday and into the weekend. With the increase in temperatures and moisture, some unsettled weather will return for the weekend. KEY MESSAGE 2) While strong to even isolated severe storms are possible this afternoon/early evening in the far NW as the region remains influenced by a departing ridge, bulk shear is a limiting factor, with marginal instability/SB CAPE from 2500 J/Kg peaking over central Indiana and diminishing to <2k J/kg between 20-22z. Enough instability for thunderstorms after 20-22z, but weakening trend to continue, with overall coverage diminishing through the evening. A greater chance for strong to severe storms on Tuesday afternoon into the evening, with main timing from 19-06z, though marginal confidence in especially onset time with varying solutions from the CAMs. Several of the CAMs ramping up SBCAPE values to 2500 J/Kg ahead of the slowly advancing cold front. Effective bulk shear increases to between 20-25kts, but CAM solutions still show pretty unidirectional flow. Strong to severe winds will be the main threat, with DCAPEs ramping up to 900+ J/Kg. The more significant low level shear remains north of the area into northern Ohio/lower Michigan. With plenty of low level moisture and PWATs ramping up to 1.6-1.8", HREF LPMM 24 hour QPF potential of 2 to 2.5" possible, so some potential for isolated minor flooding, though greater heavy rain threat remains west of the forecast area. && .AVIATION /18Z MONDAY THROUGH FRIDAY/... VFR conditions expected through the period. Line of storms approaching from Indiana should diminish as they approach the region, but kept a prob30 for KDAY from 23-03z. With increasing low level flow KLUK not as likely to experience BR, but could be some brief MVFR vsbys toward 10-12z. SW winds 20 to 20 to 25kts will diminish a bit overnight, then ramp up to near 25kts in the warm sector after ~14-16z Tuesday. OUTLOOK...Thunderstorms possible Tuesday afternoon into Tuesday night. MVFR ceilings and visibilities are possible Tuesday night into Wednesday and then again on Friday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ DISCUSSION...JDR AVIATION...JDR  469 FXUS66 KSGX 181802 AFDSGX Area Forecast Discussion National Weather Service San Diego CA 1102 AM PDT Mon May 18 2026 .SYNOPSIS... High temperatures the coast to the coastal slopes of the mountains will warm several degrees today with faster inland clearing of night and morning coastal low clouds today and Tuesday. Warming will expand into the deserts on Tuesday and continue on Wednesday as the coast and valleys begin to cool on Wednesday. Not much change in high temperatures for Thursday through Sunday with high temperatures a few to around 5 degrees above average. A more persistent coastal eddy will bring greater coverage of night and morning coastal low clouds for the middle of the week with low clouds spreading into the western valleys for early Wednesday and into the inland valleys for early Thursday. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... New Aviation and Marine Discussion... .SHORT TERM (Today through Wednesday)... Northwest to north winds for the mountains and deserts will become north to northeast this morning, then diminish through the afternoon. High temperatures for the deserts will be a few degrees cooler today. High temperatures for the coast to the coastal slopes of the mountains will warm several degrees today, as much as 10 to 15 degrees for the Inland Empire. There will be warming for most areas on Tuesday with high temperatures as much as 5 to 10 degrees warmer for the mountains, deserts, and inland valleys. For Wednesday, the coast and valleys will begin to cool while high temperatures for the mountains and deserts warm another few to around 5 degrees. While a weak coastal eddy will continue at times through Tuesday, mainly nights and early mornings, low clouds should clear faster for inland areas, especially on Tuesday. However, the local NAM- bounded WRF shows a more persistent coastal eddy developing Tuesday night and continuing into Thursday with more widespread coastal low clouds spreading into the western valleys for Tuesday night into Wednesday morning and into the inland valleys for the Wednesday night into Thursday morning as the marine layer deepens. && .AVIATION... 181800Z...Coast/Valleys...Low clouds have cleared most areas in OC and the Inland Empire, with low clouds with bases 2500- 4000ft MSL clinging to inland and coastal San Diego county for another hour or two. Low clouds may return this evening (30-50%) to coastal areas with the highest chances in coastal San Diego between 13-17Z. if low clouds do develop, bases would be AOA 1500ft MSL. Mountains/Deserts...Northerly winds will bring gusts 25-35 knots through and below mountain passes through 20-22Z. Pockets of LLWS and downdrafts in lee (south and west) of mountains will be possible. && .MARINE... No hazardous marine conditions are expected through Saturday. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ PUBLIC...Martin AVIATION/MARINE...Villafane  529 FXUS62 KTAE 181804 AFDTAE Area Forecast Discussion National Weather Service Tallahassee FL 204 PM EDT Mon May 18 2026 ...New SHORT TERM, LONG TERM, MARINE, FIRE WEATHER... .KEY MESSAGES... Issued at 151 PM EDT Mon May 18 2026 - Hot temperatures are expected through mid week. There is a high chance of highs at or above 90 across the area with the Florida Big Bend having a low chance of highs at or above 95. The heat may affect those who are sensitive, especially without cooling/hydration. - Isolated afternoon and early evening showers and thunderstorms continue through the next few days with coverage increasing late week into the weekend. Gusty winds and locally heavy rainfall are the main concerns with any stronger storms that develop. && .SHORT TERM & LONG TERM... (This Evening through next Sunday) Issued at 151 PM EDT Mon May 18 2026 Scattered showers and storms are beginning to develop over the Florida Panhandle early this afternoon. This should continue for the remainder of the day over mainly inland parts of the Panhandle into portions of southeast Alabama. Some of the storms this afternoon could produce strong wind gusts of 40-60 mph, locally heavy downpours, and frequent lightning. These will fade during the early to mid part of the evening with a warm and muggy night ahead. Lows area-wide will be in the upper 60s to lower 70s. Tuesday through Thursday, there will be less coverage of showers and storms overall as strong ridging builds overhead and PWATs decrease a bit. Rain chances are at most around 20-30% each day. It will be very hot, however, by May standards. Highs will be in the low to potentially mid 90s for much of the area over the next 3 days with some areas seeing heat index values nearing 100 for the first time this year. This level of heat could affect those who are sensitive to heat, such as the elderly, those with chronic health conditions, or those without access to adequate cooling or hydration. By late in the week into the weekend, the ridging will begin to shift a little bit more to the east as troughing nudges more into the Mississippi Valley and southern Plains. This will gradually pull in more moisture to our area with rain chances increasing heading into the holiday weekend. This would primarily be an increased chance of afternoon showers and storms. High temperatures will come back down to the upper 80s to lower 90s, but with the increased humidity, heat index values will still remain in the mid 90s to low 100s. Lows remain near 70. && .AVIATION... (18Z TAFS) Issued at 119 PM EDT Mon May 18 2026 A couple of showers and storms will be possible between KECP and KDHN this afternoon and early evening. Some low stratus may develop near KVLD in the early morning hours, but confidence is a bit on the lower side. Otherwise, VFR conditions are expected. && .MARINE... Issued at 151 PM EDT Mon May 18 2026 Gentle to moderate east to southeast breezes continue over the next several days. The highest winds will generally be tonight with some areas approaching cautionary levels, especially over Apalachee Bay. Otherwise, tranquil boating conditions are expected to continue through the end of the week. && .FIRE WEATHER... Issued at 151 PM EDT Mon May 18 2026 Generally southeasterly transport winds around 10 mph will continue each day, though the afternoon sea breeze will turn winds more southerly to southwesterly as it passes through. Dispersions will be good each day across the area. Isolated to scattered showers and storms will be possible along the afternoon sea breeze. Some of these storms may produce gusty, erratic winds as well as frequent lightning strikes. && .HYDROLOGY... Issued at 226 AM EDT Mon May 18 2026 Isolated to scattered storms will bepossible each day through the next week. These could produce locally heavy downpours, which may lead to some nuisance flooding, mainly in urban or poor drainage areas. However, widespread flooding concerns are not expected. Extreme to exceptional drought continues across the area. While the rain is beneficial, significant improvement in drought conditions is not expected. For more information on local drought impacts, please visit www.weather.gov/tae/DroughtInformationStatement. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested. However, spotters are always encouraged to safely report significant weather conditions when they occur by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 92 70 92 70 / 0 0 10 10 Panama City 87 70 87 70 / 10 0 10 0 Dothan 90 67 89 68 / 20 0 10 0 Albany 91 67 90 68 / 0 0 0 0 Valdosta 92 66 92 67 / 0 0 10 0 Cross City 94 69 94 69 / 0 0 40 10 Apalachicola 83 73 83 73 / 10 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk until midnight EDT /11 PM CDT/ tonight for FLZ112-114-115. GA...None. AL...None. GM...None. && $$ SHORT TERM...Young LONG TERM....Young AVIATION...Merrifield MARINE...Young FIRE WEATHER...Young HYDROLOGY...Young  530 FXUS63 KBIS 181804 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 104 PM CDT Mon May 18 2026 .KEY MESSAGES... - Medium to high chances (40 to 80 percent) for showers this afternoon through this evening south central and into the James River Valley, low chances elsewhere. - Cold overnight low temperatures near or slightly below freezing tonight (west and north central), and Tuesday night (southwest, central, and east). - Temperatures warming back to above normal by late in the work week and for the weekend, with near daily chances for showers and a few thunderstorms. && .UPDATE... Issued at 1253 PM CDT Mon May 18 2026 For mid-day update main change was to issue a Freeze Warning over much of western and north central North Dakota, and a Frost Advisory over remaining areas. Over the west, temperatures are still holding in the upper 30s over parts of the area, with some areas expected to dip into the upper 20s behind any precipitation that we see tonight. Further east where the Frost Advisory is in place, confidence is a little lower on low temperature forecast because on one hand widespread cloud cover is in place, but on the other is the colder air pushing in. Although we do not technically expect "frost", forecast temperatures dip into the low 30s, which if they dip even a little more plants could be damaged. Therefore wanted to bring awareness to the temperatures. UPDATE Issued at 930 AM CDT Mon May 18 2026 Fog over the area has mainly dissipated as visibility has improved. Otherwise, going forecast remains on track with rain showers over South Dakota continuing to lift northeasterly. UPDATE Issued at 645 AM CDT Mon May 18 2026 Webcams and observations showing some dense fog across north western and north central North Dakota this morning. This fog should diminish by mid to late morning, however have issued an SPS for its potential impacts on the morning commute. Otherwise low clouds remain across the area. Shower activity has diminished, although some pockets of drizzle are still possible. The next round of rain is starting to take shape in western South Dakota. Left PoPs as is as we continue to monitor the progression of this next round. Lastly SPC does have southeastern North Dakota in a general risk for thunderstorms today. The better instability is in South Dakota and further south today. Perhaps some lightning is possible this afternoon with heavier showers, however, the overall threat for thunderstorms today is very low. && .DISCUSSION... Issued at 357 AM CDT Mon May 18 2026 Upper level trough will push across the state later today bringing the next round of showers. Before doing so, lingering low level moisture will bring abundant cloud cover and cooler temperatures this morning through today. A few rain showers and pockets of drizzle will also be found this morning, along with some patchy fog, as a result of this lingering low level moisture. An increased gradient on the surface of the exiting surface low may also bring some breezy north winds today to southern and eastern portions. Temperatures today will be quite cool and generally in the 40s, with some lower 50s. Later today through this evening, the mentioned upper level wave will move through bringing more organized showers to the state. Best chances for these showers remain across south central and eastern portions of the state where the better synoptic lift is. Isolated to perhaps scattered showers are possible elsewhere. QPF will be much less from this second wave, with the higher amounts being a tenth to a quarter of an inch in the southeast. The mentioned wave moves eastward tonight, although a few showers may linger as it does so especially in the west. Perhaps a rain snow mix is possible from these lingering showers. Cooler temperatures will also be found tonight with lows in the 30s. Depending if clouds can clear, some frost is possible. Low level moisture looks to linger, although some far western portions could at least partially clear which may be the area to monitor tonight for frost. Although not in the forecast, perhaps some patchy fog is also possible tonight into Tuesday morning with light winds and lingering low level moisture. Surface high will push this low level moisture eastward on Tuesday. Some isolated showers are possible in the morning as it does so, then look for clearing skies and slightly warmer temperatures in the 50s. Breezy northwest winds could also linger in the east for Tuesday. This surface high combined with ridging aloft will bring clearing skies tonight and colder temperatures. Most areas are forecast in the 30s, with some areas in the central and east could see temperatures near to slightly below freezing. Widespread frost is still likely, with perhaps some freeze highlights also needed. There still remains some uncertainty if we fully clear out and if a switch to a breezy southerly flow occurs overnight. Will continue to message the cold temperatures, yet hold off on any highlights at this time for Tuesday night into Wednesday morning. A breezy southerly flow is then forecast for Wednesday, with another broad trough pattern approaching the state. Warmer temperatures will return as a result with highs forecast in the 70s. Some lower RH values may also return, although recent rainfall should help with fuels. This trough pattern could also bring some isolated to scattered showers and thunderstorms in the afternoon and evening for Wednesday. Broad trough pattern then looks to continue through the end of the upcoming week. This is forecast to bring seasonable temperatures and near daily chances for showers and thunderstorms. Instability looks limited during the work week, thus the chances for severe thunderstorms looks low at this time. Daily high temperatures in the 60s with lows in the upper 30s to mid 40s are also expected, limiting the frost and freeze threat for the end of the week. Warmer temperatures are then possible for the upcoming weekend with highs in the 70s Saturday to perhaps near 80 on Sunday. Current NBM chances for precipitation this coming weekend are low, although zonal flow aloft and some weak instability could change this with each forecast update. These warming temperatures could also bring lower RH values in the afternoon this weekend. Winds generally look light, which should limit the fire weather threat. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1253 PM CDT Mon May 18 2026 Low stratus over the state will continue to bring widespread MVFR with localized IFR ceilings through the rest of today into the overnight hours. Improvement is expected late tonight over far western North Dakota, then over much of western and parts of north central North Dakota Tuesday morning. && .BIS WATCHES/WARNINGS/ADVISORIES... Freeze Warning from 1 AM CDT /midnight MDT/ to 9 AM CDT /8 AM MDT/ Tuesday for NDZ001>005-009-010-012-017>020-022-031>033- 040-041-043-044-055>059. Frost Advisory from 1 AM CDT /midnight MDT/ to 9 AM CDT /8 AM MDT/ Tuesday for NDZ013-023-025-035>037-042-046>048-050-051- 060>062. && $$ UPDATE...JJS DISCUSSION...Anglin AVIATION...JJS  984 FXAK67 PAJK 181811 AAA AFDAJK Southeast Alaska Forecast Discussion...UPDATED National Weather Service Juneau AK 1011 AM AKDT Mon May 18 2026 .UPDATE.../For 18z TAF issuance/... Monday morning kicks off with widespread MVFR to IFR conditions across SE AK, driven by low CIGS in the wake of a departing front, with the lowest CIGS (less than 1000 feet) generally lurking around the Outer Coast and Icy Strait Corridor. Some improvement is expected through the day on Monday, with a general trend upwards into MVFR conditions. Winds across airports will largely remain on the moderate side (7-12 kt), save for the far northern panhandle, where Skagway will see sustained winds of 15 to 25 kt. Through Monday night into Tuesday morning, the forecast diverges. A weak wave moving in across the northern half of the panhandle will see CIGS diminish once more, with the potential for a few locations like Gustavus to slip back into IFR. Conversely, improving conditions will continue across the southern panhandle, although there is the possibility of overnight fog which, where it forms, would bring with it drastic restrictions in VIS and CIGs. && .SYNOPSIS... Key Messages: - Onshore flow continues showers through Monday, mainly for the northern and central panhandle - A weak shortwave brings rain back to the northeastern gulf coast Monday night into Tuesday before another system moves into the gulf Wednesday && .SHORT TERM...A decaying front is continuing to move inland Monday morning, bringing widespread rain to the panhandle. Along the northern gulf coast, the front has pushed through with only occasional post frontal showers showing up as of this discussion. This will continue to be the trend through the day Monday, as weak ridging builds in behind the front. Onshore flow will continue though, with showers remaining likely for the northern and central panhandle into Tuesday. No significant changes made to the forecast in the short term aside from lowering winds in some parts of the inner channels to match the weakening front. A weak shortwave in the northern gulf is expected to push into Yakutat and the northeastern gulf coast through Monday evening, which will continue rain chances and overcast skies throughout the northern panhandle. This pattern continues through Tuesday, with another organized band moving into Yakutat preceding the next system for Wednesday. For the southern panhandle, clearing skies could lead to fog development early Tuesday morning impacting marine and air travel through the morning hours. .LONG TERM.../Wednesday through Friday/...The front moving in late Tuesday night is expected to bring widespread moderate rain to the entire panhandle through the day Wednesday before trailing off late Wednesday night. Peak precipitation accumulation is expected to occur between Tuesday afternoon to Wednesday afternoon based on the current thinking for timing of the front. There is 80% confidence that Yakutat will receive between 1-1.75 inches, Juneau to receive 0.5-1.25 inches, Sitka to receive 0.6-0.8 inches, and Ketchikan to receive 0.25-0.55 inches of rain in the 24 hour period mentioned. There are no flood risks expected at this time. As the front moves in, winds across the panhandle look to increase to 20-25 mph with gusty conditions and will settle again Thursday morning after the front moves fully through the area. The overall pattern for the rest of the week continues to be unsettled onshore flow. This will bring periods of rain and overcast conditions, mainly focused on the northern panhandle. The southern and part of the central panhandle could see periods of clearing intermixed with light rain showers for the rest of the week. Winds look be mainly calm for the rest of the period as there is no well defined front currently expected. Looking ahead for the Saturday night through Sunday period, ensemble guidance suggests a negatively tilted trough will advance into the Gulf of Alaska. While this system is trending deeper, it is expected to bring relatively benign winds and precipitation, with the primary impacts focused on the southern panhandle and Clarence Strait to Dixon entrance region. Guidance suggests with 90% confidence that any hazards expected with this are low end small craft advisories in the aforementioned zones. && .AVIATION.../through Monday night/...Mainly MVFR flight conditions through Monday night as rain slowly diminishes behind the departing front. Pockets of IFR VIS/CIGs possible through the morning. Some slight improvements with VFR flight conditions possibly developing as winds will become 8-15kt this afternoon. Stronger winds 15-22G25-32kt will develop for PAGY behind the front as the gradient strengthens. Winds will diminish through the night, possibly allowing the return of MVFR VIS/CIGs, especially for PAYA. Any lingering LLWS concerns will diminish through the morning as the front pushes east of SE AK. && .MARINE...A weakening front will continue to lift inland across the SE Alaska panhandle Monday with a weak short wave following Monday evening. Another organized system will move into the gulf late Tuesday into Wednesday. Coastal Waters: As previously forecast, winds have become southwesterly 10-15kts behind the front in the gulf. Additionally, swell has shifted to be consistently southwesterly ranging 7 to 9 ft and should ease to 3 to 5 ft by Monday night. Between the easing winds and swell combined seas in the outer/inner coastal zones are expected to go from 15 to 17 ft to 6 to 8 ft by Monday night. Conditions are not expected to change drastically from Monday night onward. That said, there are a few shortwave disturbances that could boost winds primarily in the near coastal zones. As of this forecast, the majority of the area is expected to remain below gale for much of the week ahead. Inner Channels: As of early Monday morning, the front has pushed into the inner channels and begun lifting into the interior. E-W orientated channels have including Cross Sound have already reported winds shifting westerly, though Icy Strait has split flow as of this discussion. Winds will generally ease over Inner Channels as the front continues to lift inland. The one exception will be Lynn Canal, which will continue to see southerly winds up to 20 kt for most of the day. Looking past Monday, weak shortwaves moving over the area are expected to increase winds over portions of the area, as of right now low end SCA seem to be the most likely but this could change as more higher resolution guidance becomes available for this period. Other than these shortwaves the only thing to note would be some potential fog development overnight early Tuesday due to expected diminishing cloud cover from Frederick Sound southward. && .AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...None. MARINE...Small Craft Advisory for PKZ641>644-651-652-661>664-671-672. && $$ SHORT TERM...STJ LONG TERM...AGP/BAS AVIATION...GFS MARINE...STJ Visit us at http://www.weather.gov/Juneau  973 FXUS63 KLOT 181810 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 110 PM CDT Mon May 18 2026 .KEY MESSAGES... - A few additional rounds of showers and thunderstorms today and Tuesday, some of which could be strong to severe mainly during the afternoon hours. - Summer-like warmth and breezy winds at times will prevail through Tuesday, then cooler temperatures return for the middle of the week. - Milder weather returns heading into the weekend, though with at least intermittent shower/thunderstorm potential. && .DISCUSSION... Issued at 347 AM CDT Mon May 18 2026 Regional radar mosaic shows a linear MCS moving across the Mississippi River into western WI/IL early this morning. There has been a notable weakening trend to the convection over the past few hours as the complex propagates into a region of decreasing deep- layer shear and low-level instability, though storms should continue to spread eastward this morning along a composite outflow boundary at the leading edge of the convection. In fact, recent radar trends indicate a few new cells developing ahead of the line near the Quad Cities, perhaps aided by enhanced ascent associated with one or more an apparent MCVs near the IA/IL/MO border. Gusty winds of 30-40 mph with the outflow and some small hail are possible with these storms early this morning, though the overall threat of organized severe weather appears low for the next several hours. Later this morning however, diurnal warming and associated destabilization along the east/southeast periphery of the complex remnants and outflow boundary may support renewed development/strengthening of convection with more of a severe threat into this afternoon. Though depending on how far the outflow boundary makes it this morning, this would likely be across the south/far east portions of the forecast area. Farther north/northwest, lingering stratiform rain and cloud cover this morning looks to limit destabilization and recent CAM trends have been consistently dry there during the day/evening. Farther to the west, early morning GOES vapor imagery indicates another mid-level short wave rounding the base of a western CONUS long-wave trough. Widespread strong convection is progged to develop late this afternoon and evening across KS/NE/IA once again in response, eventually growing upscale into another eastward- propagating linear MCS. Similarly to this morning, CAM runs continue to depict a similar weakening of this system as it reaches the Mississippi River and spreads into WI/IL early Tuesday morning with associated relatively low severe potential. The lingering MCS cold pool footprint and residual cloudiness will likely delay destabilization into midday Tuesday, though additional storm development appears possible across the southeast half of the forecast area Tuesday afternoon/evening as the cold front finally pushes through the forecast area. Stronger mid-level flow on the southeastern periphery of the aforementioned short wave will likely support enough storm organization for a hail/wind threat during this time. Following the cold front, surface high pressure is progged to build east into the western Great Lakes region Wednesday and Thursday. Dry, but breezy and cooler weather is expected both days, with temps mainly in the 60s, but only in the 50s near Lake Michigan with northeast-east flow off the lake. Nighttime lows in the 40s are expected. The high then drifts off to the east Thursday night, with the upper level pattern favoring a series of mid-level disturbances tracking through the area Friday into the weekend. This will support milder temperatures, but also some occasional shower/thunderstorm chances into the holiday weekend. Ratzer && .AVIATION /18Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 109 PM CDT Mon May 18 2026 Wind field has been substantially altered by storms this morning, but will revert back to a south-southwest direction early this afternoon. Pressure gradient is baggier in the wake of the storms than originally forecast, so gustiness of the winds may be slower to develop today than indicated in the TAFs. Showers and storms that develop over the central Plains today will move east and likely reach northern Illinois in a quickly decaying state late tonight/early Tuesday morning. Confidence is low in whether this activity will reach the terminals, so opted to just hang onto a PROB30 in the TAFs. Finally, confidence in winds Tuesday is on the lower end of the spectrum. There is a chance wind fields could be altered by diminishing storms, which could play havoc on directions and speeds. However, if wind fields aren't significantly altered, then winds will likely be even stronger than indicated in the TAFs. - Izzi && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago  218 FXUS62 KILM 181813 AFDILM Area Forecast Discussion National Weather Service Wilmington NC 213 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... Discussions updated. Precip chances lowered during the Thursday-Sunday timeframe due to the anticipated pattern supporting mainly isolated to scattered showers and storms as opposed to widespread precip. && .KEY MESSAGES... 1) Inland portions of the eastern Carolinas should see their longest heat wave of the year so far with 90+ degree heat expected to continue through Thursday. 2) Rain chances should increase, especially inland, beginning Thursday as a front temporarily stalls in the Carolinas. && .DISCUSSION... KEY MESSAGE 1...Inland portions of the eastern Carolinas should see their longest heat wave of the year so far with 90+ degree heat expected to continue through Thursday. An upper high will shift into the Atlantic and leave an axis of higher heights from the Gulf into the central Atlantic, and this is responsible for the sustained period of hot inland temperatures, which should last through Thursday. Sinking air below the upper ridge will create a deep warm, dry layer in the middle troposphere, supporting abnormally warm surface temperatures. Models have maintained their 850 mb temp forecasts of +16C to 18C (at or above the 90th percentile climatological values for this time of year), which increases confidence in our forecast of 90+ degree heat continuing through Thursday for locations away from the daily cooling influences of the sea breeze. Our forecast is for an additional three days (Tuesday through Thursday) of 90+ degree heat inland. Since Florence and Lumberton highs reached 90 degrees on Sunday, a five day streak would eclipse this year's earlier streak of four days of 90 degree temps recorded from April 15-18 in both Florence and Lumberton. Coastal portions of the Carolinas should remain significantly cooler than inland due to sustained south winds dragging air across nearshore water still near 70 degrees. The upper ridge will become increasingly narrow with time as an upper low strengthens across the northern Bahamas Tuesday into Thursday. This feature looks a lot like an early season TUTT low, but any enhanced convection or other sensible weather impacts should remain far to our south. The arrival of a surface cold front Thursday afternoon should end this heat wave with temperatures returning toward normal for Friday. However, the front is expected to stall and lift back north, with troughing to the west and a ridge centered over the Atlantic supporting more of a daily pop-up convection pattern over the weekend. Thus, high temps will depend on the extent of cloud cover and precip that develops. KEY MESSAGE 2...Rain chances should increase, especially inland, beginning Thursday as a front temporarily stalls in the Carolinas. Dry weather will come to an end as a front shifts in from the north on Thursday. There's reasonable uncertainty on placement of highest POPs day to day as we deal with a stalled front in or near the area and the daily sea breeze. The front should lift north of the area into the weekend but the warm, humid air mass will continue to support at least daily pop-up shower and storm chances through the end of the period. With respect to the lowering of precip chances late in the week and over the weekend, NBM-based and GEFS/ECME precip probabilities appear overdone given the expected pattern with a ridge over the Atlantic and troughing well west of the area. While the incoming front could bring enhanced precip coverage due to surface convergence along the boundary paired with a warm and humid troposphere, little in the way of upper support is depicted amongst the global models, lending lower confidence to a widespread coverage of precip than what would be expected with 70-80% PoPs. In addition, GFS MOS and ECME MOS output both support lower probabilities for precip generally at or below 50%. Thus, PoPs were lowered until confidence increases in when and where a period of greater precip coverage can be expected. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... We have high confidence in VFR conditions continuing through 06z Tuesday. Light southerly winds could increase to 10-15 knots along the coast with the seabreeze through 00z. After 06z Tuesday, high humidity in the lowest 1000-1500 feet of the atmosphere and clear skies aloft should set the stage for the development of fog and/or low ceilings late tonight. There is some raw model and statistical guidance suggesting fog could become dense in spots, but for now we're forecasting MVFR visibility and scattered low clouds developing around 08z and persisting through 12z Tuesday morning. Once daytime heating clears up surface visibility, dry air aloft should result in fewer low clouds lingering compared to what we saw this morning. Extended Forecast...Areas of low clouds and fog are possible Wednesday through Saturday mornings, generally in the 08z-12z timeframe. Confidence is moderate. Shower and thunderstorm chances will increase across the entire area Friday into Saturday as a front stalls across the Carolinas. && .MARINE... Through Tuesday...Bermuda high pressure ridging westward across South Carolina will maintain dry weather and a light southerly wind across the area. Superimposed on this synoptic wind will be a landbreeze/seabreeze pattern that should lead to localized stronger wind speeds (10-15 kt) nearshore during the afternoons and evenings. Seas should average 2 feet across the coastal waters (2-3 feet for the waters out to 60 miles) mainly in an 8-second southeast swell. Tuesday night through Saturday... Offshore high pressure will maintain control through midweek until a cold front approaches from the north. This front looks to stall near or over the waters before lifting back northward by late Friday. Generally south winds can be expected until the front draws near, with a period of east or even northeast winds possible near the coast if the front can push offshore; otherwise, expect southeast winds ahead of the front. Speeds are expected to stay between 5-15 kts, with enhanced nearshore gustiness due to the sea breeze likely each day. Seas are expected to hold in the 2-3 ft range in the 0-20nmi zone and 3-4 ft in the 20-60nmi zone through the period, mainly driven by persistent southeasterly swells with a period of 8-9 sec. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...Coastal Flood Advisory from 10 PM this evening to 2 AM EDT Tuesday for NCZ107. SC...Coastal Flood Advisory from 8 PM to 11 PM EDT this evening for SCZ054-056. MARINE...None. && $$ WHAT HAS CHANGED...ILM KEY MESSAGES...ABW DISCUSSION...ILM AVIATION...TRA MARINE...TRA/ABW  127 FXUS63 KMPX 181812 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 112 PM CDT Mon May 18 2026 .KEY MESSAGES... - Another round of showers & thunderstorms tonight. A few could become strong to severe storms from far-southern Minnesota into western Wisconsin. The overall risk has decreased. - Seasonably cool & dry midweek. Rain chances return at the start of Memorial Day weekend. && .DISCUSSION... Issued at 108 PM CDT Mon May 18 2026 All is quiet to start the day as the surface low pressure sits almost directly over the Twin Cities. Widespread stratus and patchy fog spread out on the north and west side of the low, limiting temperatures from warming this afternoon. The cold front is essentially draped along the I-35 corridor south of the Twin Cities, while the warm front extends east from the Twin Cities slightly north of I-94. Expect scattered showers to develop across the Central Plains this afternoon, and spread north into MN and WI through the evening. The heaviest rainfall and best chance for thunder will be around 8pm to 12am. The best environment for thunder, and potentially a strong to severe storm, will be in that warm sector east of the cold front and south of the warm front (i.e. east of I-35 and south of I-94). Overall the threat has decreased due to limited instability (noted by the 1630z update to the SPC Day 1 SWO). The main threat will be large hail and strong winds, as well as localized flash flooding anywhere that thunderstorms train for several hours. Light rain will wrap up Tuesday morning as the upper level wave pushes east. At the surface, breezy northwest winds will develop and strong CAA will keep temperatures about 10-15 degrees below normal. Additional showers may develop as the cold air advects in, though saturation will be very limited throughout the profile. Mostly quiet weather will persist until this weekend as a shortwave develops over the Northern Plains. This will provide us with a few chances for rain, though ensemble QPF is mostly around a few tenths and in the range of a normal rain event for this time of year. In other words, Memorial day weekend will have occasional rain, but nothing to change plans over at this time. Temperatures will also be gradually rising throughout the week, peaking on Monday with widespread highs in the 80s possible. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1232 PM CDT Mon May 18 2026 Low stratus, MVFR-to-IFR, expected to prevail throughout this duration as a low pressure center and its associated NE-to-SW frontal boundaries remain slightly to the east of the WFO MPX TAF sites. A round of rainfall with some embedded TSRA (mainly southern MN into western WI) is expected from late this afternoon through late this evening, potentially lasting as lingering showers into the early morning hours. Visibilities will drop to as low as IFR, particularly if heavy downpours cross over any given site. Precipitation is expected to end overnight to just before dawn Tuesday morning, followed by a slow rise in ceilings during the day Tuesday. Winds will remain NE throughout, with speeds around 10kts during the day today into this evening, increasing to near 15G25kts late overnight through the day Tuesday. KMSP...Ceilings to remain in the 010-015 range through this afternoon, with a small shot of some showers developing prior to 00z this evening, After 00z, chances ramp of significantly of a swath of rain/TSRA shifting NE from southern MN into western WI. MVFR ceilings to continue, with visibilities potentially into IFR range should heavier downpours move across MSP. As the precip winds down overnight, MVFR ceilings will continue but NW winds will increase to near 15G25kts. /OUTLOOK FOR KMSP/ WED...VFR. Wind NW 5 kts, shifting to SE. THU...VFR. Wind SE 10-15G25kts. FRI...Mainly VFR. Chance MVFR/-RA. Wind SE 10-15kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...BED AVIATION...JPC  112 FXUS64 KMOB 181811 AFDMOB Area Forecast Discussion National Weather Service Mobile AL 111 PM CDT Mon May 18 2026 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... Issued at 111 PM CDT Mon May 18 2026 - A HIGH risk of rip currents is in effect for all area beaches on Tuesday. - Rain chances increase by mid to late next week, especially over the northwestern portion of the forecast area. - Localized patchy fog will be possible late tonight and late Tuesday night. && .DISCUSSION... Issued at 111 PM CDT Mon May 18 2026 An upper ridge builds across the extreme southeast states through Tuesday then weakens going into Thursday before rebuilding late this weekend. A large upper trof pattern located mostly over the western half of the CONUS eventually progresses mostly across the interior eastern states through this weekend, and in the process maintains a southwesterly flow aloft over the forecast area. A series of shortwaves move through the southwesterly flow over the area meanwhile, which along with a weak sea breeze circulation developing each day will lead to convective development. That said, subsidence effects associated with the nearby upper ridge are anticipated to make for a mainly dry day on Tuesday, then going into Friday tend to limit convective development over eastern portions of the area. Have gone with slight chance to chance pops on Wednesday for much of the area, then for Thursday will have slight chance to chance pops mainly west of I-65. While the upper ridge is anticipated to rebuild going into the weekend, it also becomes oriented mainly across the Florida peninsula. Predominately likely pops return for Friday through Sunday over western portions of the area, while further to the east pops gradually trend to chance pops. Patchy fog will be possible late tonight and late Tuesday night, with the potential for some localized thick fog. A moderate risk of rip currents is expected through tonight, then a High Risk follows for Tuesday. A moderate risk is anticipated for Wednesday with a low risk for Thursday and Friday. /29 && .AVIATION... (18Z TAFS) Issued at 111 PM CDT Mon May 18 2026 Predominately VFR conditions are expected through early this evening, then MVFR to IFR ceilings develop across the area beginning later in the evening. Conditions improve to VFR during mid Tuesday morning. Patchy fog development is possible overnight. Southeasterly winds 5-15 knots diminish to 5 knots or less this evening, then return to 5-10 knots Tuesday morning. /29 && .MARINE... Issued at 111 PM CDT Mon May 18 2026 A light to occasionally moderate southeasterly flow will prevail through Saturday. Seas will build slightly through tonight then diminish Wednesday into Thursday. /29 && .PRELIMINARY POINT TEMPS/POPS... Mobile 71 87 70 87 / 0 0 0 10 Pensacola 72 84 72 85 / 10 0 0 10 Destin 71 83 71 84 / 0 0 0 10 Evergreen 66 91 67 90 / 10 20 10 30 Waynesboro 71 90 70 89 / 0 10 10 30 Camden 68 89 69 88 / 0 0 10 30 Crestview 66 91 67 91 / 10 20 0 30 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...High Rip Current Risk from Tuesday morning through Tuesday evening for ALZ265-266. FL...High Rip Current Risk from Tuesday morning through Tuesday evening for FLZ202-204-206. MS...None. GM...None. && $$  104 FXUS65 KFGZ 181811 AFDFGZ Area Forecast Discussion National Weather Service Flagstaff AZ 1111 AM MST Mon May 18 2026 .SYNOPSIS...Cooler and breezy conditions remain today behind a cold front. Gradually warmer and less windy conditions return for the remainder of the week. && .DISCUSSION...Today...Gusty winds remain over the higher terrain this morning as a cold front moves across northern Arizona. Winds should gradually subside from west to east with the frontal passage, thus for most of the area the Wind Advisory will expire by 5 AM MST / 6 AM MDT. Across eastern Arizona, FROPA looks to still be a couple hours later, so the advisory has been extended to 11 AM MST / 12 PM MDT. As the aforementioned front moves through the region, a brief period of showers will move from west to east, primarily near the AZ/UT border. Given that surface moisture will remain fairly minimal, much of the activity is expected to be either virga or light in nature. The best shot at measurable precip looks to mainly be across the Kaibab Plateau, an potentially Black Mesa and the Chuska Mountains as well. 00Z HREF guidance appears to be a bit bullish with precipitation chances, brining them as far south of as the Mogollon Rim. However, model soundings don't really support this outside of a subtle increase in low-level moisture early this morning. Nevertheless, PoP chances were maintained in the Flagstaff area for the potential for a couple isolated showers. Colder air aloft does move in with the front, so a few snow flakes may mix in at times above 7000-7500 feet. However any potential for measurable snow looks to remain above 7500-8000 feet and primarily near the Kaibab Plateau. Tuesday through Sunday...Zonal flow sets in behind the low earlier in the week. Warming temperatures and dry conditions look to ensue as a result, with a return to near-normal highs by the middle to end of next week. Weak troughing will keep winds fairly light each day, with mainly only the typical afternoon breezes expected. Ensemble guidance all signal towards PWATs increasing slightly by next weekend as a weak low looks to increase moisture advection into Arizona. For now, this looks to mainly result in a slight chance for some high-based showers around the White Mountains. && .AVIATION...Monday 18/18Z through Tuesday 19/18Z...VFR conditions. Winds W/SW 10-20 kts with gusts to 30-35 kts through 03Z, then becoming N/NE 5-10 kts. OUTLOOK...Tuesday 19/18Z through Thursday 21/18Z...VFR conditions with W/SW winds 5-15 kts with gusts 20-25 kts each day. && .FIRE WEATHER...Today and Tuesday...Slight chance for light showers and possibly a thunderstorm this morning across far northern Arizona, otherwise dry and cool conditions. Winds west/southwest 10- 20 mph with gusts 25-35 mph, subsiding to 5-15 mph on Tuesday. Minimum afternoon RH 10-30%, falling to 10-20% on Tuesday. Wednesday through Friday....Dry conditions with gradually warming temperatures. Winds west/southwest 5-15 mph each day, along with minimum afternoon RH 5-15%. && .FGZ WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 6 PM MST /7 PM MDT/ this evening for AZZ011- 014-017. && $$ PUBLIC...Humphreys AVIATION...Lewandowski FIRE WEATHER...Humphreys For Northern Arizona weather information visit weather.gov/flagstaff  284 FXUS62 KJAX 181815 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 215 PM EDT Mon May 18 2026 .KEY MESSAGES... For the latest NE FL and SE GA Daily Key Messages please visit: https:/www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf - High Risk Of Rip Currents at All Area Beaches through Tuesday. - Areas of Locally Dense Fog for Inland Locations Along and North of Interstate 10 Early on Tuesday Morning. - Widely Scattered Afternoon & Evening Thunderstorms at Inland Locations from Tuesday through Thursday. - Scattered Afternoon & Evening Thunderstorms Area-Wide from Friday through Memorial Day. - Historic Drought Conditions Continue Across Much of Our Region. && .NEAR TERM /THROUGH TONIGHT/... Main Highlights This Period: - High Risk for Rip Currents at All Area Beaches this Afternoon. - Areas of Locally Dense Fog Possible for Inland Locations Along and North of Interstate 10 Late Tonight. Afternoon surface analysis depicts strong Atlantic high pressure (1029 millibars) centered near Bermuda and extending its axis westward across the southeastern states. Aloft...ridges were centered over Mexico's Yucatan peninsula and east of the North Carolina Outer Banks, with a Tropical Upper Tropospheric Trough (TUTT) spinning to the northeast of the Bahamas. Dry northwesterly flow prevails aloft locally in between the two ridges. Latest GOES-East derived Total Precipitable Water imagery indicates that a dry air mass has advected over our entire area from east to west overnight and this morning, with PWATs around of slightly below 1 inch for locations east of the Apalachicola River and north of the Interstate 4 corridor. A flat cumulus field was located along and east of the U.S. Highway 301 corridor in northeast and north central FL, with fair skies otherwise prevailing. Temperatures were rising through the mid and upper 80s for locations west of I-95 as of 18Z, while breezy easterly winds have kept temperatures in the lower 80s at coastal locations. A wider range of dewpoints prevail across our region, with values falling through the mid and upper 50s across inland portions of southeast GA and northern portions of the Suwannee Valley, while values ranged from 65-70 at most coastal locations. Breezy, convergent easterly flow could bring a few light showers or sprinkles to the Flagler County coastline this afternoon, but a dry and mostly subsident air mass will otherwise limit shower development this afternoon and evening for most of our area. Slightly deeper moisture over north central FL will perhaps develop a shower over Marion County late this afternoon, but thunderstorm activity is unlikely. Winds at inland locations will decouple towards midnight, setting the stage for fog development for inland locations along and north of the Interstate 10 corridor during the predawn and early morning hours on Tuesday. Areas of locally dense fog could occur towards sunrise across inland portions of southeast GA. Meanwhile, convergent onshore winds may provide a slightly better chance for showers developing over the Atlantic waters adjacent to northeast FL to arrive onshore towards sunrise, mainly for coastal locations from St. Augustine southward. Marine cumulus and stratocumulus clouds will otherwise increase in coverage from south to north along the I-95 corridor during the predawn and early morning hours on Tuesday, with these clouds and an onshore breeze keeping coastal lows mostly in the lower 70s. Lows at inland locations will generally fall to the mid and upper 60s. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... - Daily thunderstorms Tuesday and Wednesday afternoons as the Atlantic sea breeze pushes inland towards the I-75 corridor. - Rip currents at area beaches will be a concern; High risk likely into midweek. Onshore flow persists through midweek as high pressure remains over the Bermuda region. Chances of precipitation return on Tuesday and Wednesday as moist air moves in from the Atlantic, bringing PWATs upwards to 1.5" each afternoon. With the inland push of the Atlantic sea breeze, activity will be focused over inland locations towards the I-75 corridor and north central FL each afternoon. The onshore flow will continue to bring breezy conditions along the coast, with gusts up from 15mph to 20mph possible each afternoon. Daytime highs each afternoon will be in the lower 90s over inland locations prior to the onset of any showers or storms, while coastal locations will have highs in the mid to upper 80s. During the overnight hours Lows will be in the 70s at the coast, while inland areas gradually fall to the mid/upper 60s. Patchy fog is possible inland both Tuesday and Wednesday mornings. && .LONG TERM /THURSDAY THROUGH MONDAY/... Main Highlights This Period: - Daily afternoon thunderstorms; best coverage and strongest storms expected along the sea breeze mergers. Rain chances Thursday are pretty isolated, near 20% inland, as onshore winds continue. Precipitation chances increase area-wide Friday through the weekend as a front stalls near northern Georgia then lifts northward, and steering flow becomes more southerly, allowing sea breeze mergers in a more central location. Highest storm chances overall will be Saturday and Sunday afternoons and evenings, between I-95 and I-75 where the Gulf and Atlantic sea breezes interact. With PWATs near 1.5-1.75" there is potential for locally heavy downpours within storms. Each day, high temperatures will generally be in the low 90s inland, and a little cooler near the Atlantic coast with mild low temps in the 70s. && .AVIATION /18Z MONDAY THROUGH 18Z TUESDAY/... VFR conditions will prevail at the regional terminals through at least 06Z Tuesday. Periods of IFR visibilities are expected after 06Z at VQQ. Marine cumulus and stratocumulus are expected to push onshore during the predawn hours on Tuesday along the northeast FL coast, and confidence was high enough to maintain prevailing MVFR ceilings of 2,000 - 2,500 feet at SGJ after 07Z. A brief shower cannot be ruled out at SGJ during the predawn or early morning hours on Tuesday. Ceilings of 2,500 - 3,000 feet will then shift northwestward across the Duval County terminals towards or after 12Z. VFR conditions are expected to prevail at GNV, and confidence was too low to indicate MVFR ceilings at SSI later on Tuesday morning. Easterly surface winds will remain sustained near 15 knots at the SSI and SGJ coastal terminals, as well as at the Duval County terminals through around 01Z, while speeds at GNV increase to 10-15 knots from around 20Z through around 01Z. Surface winds will shift to southeasterly at the coastal terminals after 03Z, with speeds diminishing to around 10 knots. Winds at the inland terminals will diminish to 5-10 knots after 02Z. East to southeasterly surface winds will then increase to around 10 knots by 16Z Tuesday. && .MARINE... Atlantic high pressure centered to Bermuda will continue to extend its axis across the southeastern states through midweek. An easterly wind surge late this afternoon through this evening will result in Caution level wind speeds for the northeast Florida waters. Prevailing east to southeasterly winds will continue across our local waters during the next several days, with isolated to widely scattered showers and perhaps a few isolated thunderstorms possible, mainly during the overnight and early morning hours. A frontal boundary will briefly stall over the southeastern states late this week before lifting northward as a warm front during the Holiday weekend. Caution conditions will again be possible for the near shore waters from Friday through early next week as Atlantic high pressure becomes reinforced near Bermuda. Rip Currents: An easterly wind surge will combine with the outgoing tide and breakers of 2 to 4 feet to create a high rip current risk at all area beaches this afternoon, with similar conditions on Tuesday likely keeping this high risk in place. Persistent east to southeast winds will keep at least a moderate risk in place at area beaches on Wednesday and Thursday, with high risks again possible from Friday through the upcoming Holiday weekend, as late afternoon and evening easterly wind surges potentially return. && .FIRE WEATHER... ...PATCHY HIGH DISPERSIONS THIS WEEK... The combination of deep mixing and sufficient southeasterly transport winds will generate generally good to high dispersions inland each afternoon through the week. Patchy high dispersions will be present over inland locations Tuesday, Thursday, and Friday. Moisture will continue to filter into the area, leading to MinRH not being of particular concern this week. Moisture will steadily increase each day, with thunderstorms possible each afternoon and evening, mainly for inland northeast FL through Thursday, then area- wide Friday through next weekend. FOG POTENTIAL AND OTHER REMARKS: Isolated thunderstorms each day Tuesday onward. Patchy fog possible Tuesday and Wednesday mornings for inland locations. && .PRELIMINARY POINT TEMPS/POPS... AMG 64 90 64 90 / 0 20 0 10 SSI 72 84 73 84 / 0 0 0 0 JAX 68 88 69 89 / 10 0 0 10 SGJ 73 87 73 87 / 10 10 0 10 GNV 69 92 69 92 / 0 30 0 30 OCF 70 91 70 91 / 10 30 0 30 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...High Risk for Rip Currents through late Tuesday night for FLZ124- 125-138-233-333. GA...High Risk for Rip Currents through late Tuesday night for GAZ154- 166. MARINE...None. && $$  291 FXUS62 KRAH 181815 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 215 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... * No major changes. && .KEY MESSAGES... As of 215 PM Monday... 1) Hot and mainly dry through Wednesday. 2) Rain chances return mid-week, highest on Thursday, and linger through the weekend. Low confidence in high temps Thursday and especially Friday. && .DISCUSSION... As of 215 PM Monday... KEY MESSAGE 1... Hot and mainly dry through Wednesday. An unseasonably strong mid/low-level anticyclone (700mb heights well exceeding the daily max at GSO, MHX, CHS, and RNK), and strong cap at the base of steep mid-level lapse rates (associated with a modified EML and persistent subsidence) sampled in the 12z RAOB data over Carolinas and portion of the Southeast, will keep conditions capped and void of precipitation amidst seasonably moist deep-layer moisture in place. Warm temperatures though the mid/low-lvls will exceed the 99th percentile through at least Wednesday and support several days of hot conditions at the surface when temperatures should regularly eclipse 90 degrees by mid-afternoon. Given central NC's position within the described weather pattern above, there are minimal failure modes and reasonably high confidence in the forecast high temperatures through Wed. Minimal mixing out of dew points have been observed over the past couple days over the Carolinas, and adjusted heat indices will remain below triple-digits, but still reach into the mid-90s in most locations. This kind of early-season heat can still be unexpectedly dangerous, as people have not yet become acclimated to the hot weather. The daily experimental Heat Risk is expected to peak at Moderate (level 2 of 4) today through Wed, but may reach Major (level 3 out of 4) in urban areas around the RTP. This kind of heat is quite unusual for this time of year and has historically led to high levels of heat illness, with sensitive individuals and those without adequate cooling particularly vulnerable. And with just a modest breeze and lots of sunshine each day, the WBGT index will also be elevated, so spending time in the shade is encouraged, especially for those working or exercising outdoors. KEY MESSAGE 2... Rain chances return mid-week, highest on Thursday, and linger through the weekend. Low confidence in high temps Thursday and especially Friday. The mid-level ridge will weaken and shift out of the region Wed/Wed night as a s/w tracks ewd across the Northeast US/mid-Atlantic. The sub-tropical ridge may once again strengthen and lift newd across the region Thu night through Sat, with several s/w disturbances tracking across the Plains and MS Valley. At the surface, a pre- frontal trough will develop over the area on Wed, with Bermuda high pressure to the east and a cold front approaching from the north, remaining in place until the cold front slides southward across central NC on Thu. A brief CAD may set up Thu night into Fri as high pressure tracking across the Northeast US ridges swd into the area. Expect the front to lift nwd back across the area Fri night/Sat, however the spread in available guidance increases beyond Fri and details remain uncertain thereafter. Precipitation: The northern and northwest Piedmont could see showers/isolated storms as early as Wed evening, however the better chances will come Thu along and ahead of the backdoor cold front as it moves into and across the area. In the wake of the front, warm air advecting in above the cooler, stable boundary layer could result in some light rain Thu night into Fri over central NC. Assuming the wedge erodes Fri night into Sat and a warm front lifts nwd across the area, there will be the chance for additional diurnally driven convection overthe weekend, especially along differential heating boundaries. Temperatures: Highs Thu will be impacted by the timing of the front and the convection ahead/along it. For now, expect highs ranging from around 80 degrees north to low 90s south. There is a large bust potential wrt highs on Fri given the potential for CAD to briefly set up and possible continued rain into it. For now have highs ranging from around 70 degrees NW to low/mid 80s south, but with below average confidence. Lows Thu and Fri nights expected to range from mid 50s north to mid 60s south. Generally expect temperatures to moderate back to near/slightly above normal over the weekend. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... As of 100 PM Monday... Prevailing VFR conditions are expected through the 24 hr TAF period. Scattered fair weather cu with bases around 5-7 kft will continue across the forecast area until dispersing shortly before sunset. Enhanced moisture at the surface is expected to lift north from Coastal Carolinas to produce another round of low-stratus and fog, but forecast confidence on reaching any central NC terminals is low. Outlook: Threat for morning low-stratus and mist will again be possible Wed and Thurs morning within this persistence pattern. Showers and storms will be possible as early as Wed evening around INT/GSO, but more likely Thurs surrounding a backdoor cold frontal passage and breezy northwest winds. Brief classical-CAD will likely bring sub-VFR cigs to all terminals behind the fropa that will likely persist into Fri, especially in the typical CAD regime at INT/GSO and potentially RDU. && .CLIMATE... Record High Temperatures: May 18: KGSO: 95/1911 KRDU: 95/1906 KFAY: 96/1911 May 19: KGSO: 96/1911 KRDU: 95/1962 KFAY: 96/2022 May 20: KGSO: 95/1917 KRDU: 96/2022 KFAY: 99/2022 Record High Minimum Temperatures: May 18: KGSO: 70/2015 KRDU: 72/1896 KFAY: 71/2018 May 19: KGSO: 68/2018 KRDU: 70/2022 KFAY: 75/1930 May 20: KGSO: 68/2022 KRDU: 69/2019 KFAY: 71/2022 May 21: KGSO: 67/2022 KRDU: 71/1898 KFAY: 71/2025 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...AS/10 AVIATION...AS CLIMATE...RAH  232 FXUS63 KGID 181813 AFDGID Area Forecast Discussion National Weather Service Hastings NE 113 PM CDT Mon May 18 2026 .KEY MESSAGES... - A handful of severe storms capable of producing large hail, damaging wind gusts or an isolated tornado will be possible between 3-8PM today. The severe threat will mainly be for places near and east of HWY-81. - A few showers, areas of drizzle and non-severe thunderstorms will be possible later this morning to afternoon across areas outside of the severe threat. - Highs, following the passage of a cold front today, will peak in the 50s and 60s for much of the area. A few north central Kansas locations as well as far southeast nebraska areas could see highs in the 70s. - The next chance of precipitation will come Wednesday night (40-50% chance). - Highs the rest of the week will stay in the 60s for Tuesday/Wednesday/Thursday, the low to mid 70s for Friday and the upper 70s to low 80s for Saturday. && .UPDATE... Issued at 235 AM CDT Mon May 18 2026 Today... Severe storms will again be possible across a few of the same locations that have observed severe weather across the past two days (Primarily north central Kansas and Nebraska locations east of HWY- 81). A persisting trough that has stalled out across the intermountain west region this past weekend will once more steer a southwesterly jet overtop of the Central Plains today. A cold front this morning resides across parts of central Kansas and eastern Nebraska. This feature will become the day's primary storm forcing mechanism. The cooler and drier airmass behind the front should dampen the severe weather potential for much of our northwest half of the area including our central/Tri-Cities area (though showers and weak storms may still be possible). Highs in response to the gusty cool air advecting winds behind the front should also struggle to break out of the 50s to low 60s beyond a few north central Kansas and far southeast Nebraska locations. As far as the storms go this afternoon (between 3-8PM), all convective types will be possible with all hazards in the mix (large hail, damaging winds, and a few tornadoes). A warm, moist and unstable airmass ahead of the cold front will offer plenty of energy to allow storms to erupt and quickly become severe (up to 1,500- 4,000J/kg of MUCAPE). Southerly winds ahead of the front and underneath the southwesterly jet will provide enough shear for a few supercells to spin, though the strong frontal forcing should prevent storms from staying isolated for too long (squall/MCS will be favored). With how far the cold front has advanced today, its is unlikely for the severe storms to impact much of our local area (mainly for areas near and east of HWY-81 and for a few north central Kansas locations). Only a southeast sliver of the area (areas southeast of a line from York, NE to Osborne, KS) has been included in a slight (level 2 of 5) or enhanced (level 3 of 5) severe weather outlook. Though the severe storms are expected to mainly stay concentrated to the southeast of most of the area, widespread drizzle, light rain and some non-severe thunderstorms will still be possible for part of the morning and afternoon hours today. Up to 0.5" of precipitation may be possible. Tuesday & Wednesday... Cooler temperatures will take over on Tuesday and Wednesday following the passage of the cold front today. Highs are forecast to remain in the 60s with overnight lows in the 30s to low 40s. The formation of frost may have to be monitored closely across a few locations closer to the Nebraska sandhills Tuesday night as winds look to calm overnight. These calming winds will be a result from the high pressure center swooping in near the middle of the week. The next chance forprecipitation will not come until Wednesday night (40-50% chance) as a weak shortwave disturbance potentially comes pivoting out of the Rockies. && .DISCUSSION... Issued at 1235 PM CDT Sun May 17 2026 The main concern in this forecast revolves around severe convection today and on Monday. Currently, most of the area is in the warm sector, with a cold front pushing in from the west, and a dryline/triple-point expected to push in from the southwest this afternoon. The eastern half of the area should be quite unstable by late afternoon, the MLCAPE values likely in the 2000-4000 J/kg range. If anything, CAMs have trended a bit further west with storm initiation...possibly as early as 4pm...but becoming more likely by around 5pm in the Highway 281 corridor. Strong deep-layer shear will be supportive of supercells, potentially merging into multiple line segments later into the evening hours. Confidence in coverage is highest in northern parts of the area and southern portions of the area, areas to the south and east of Hastings may not Generally the entire area near/east of Highway 281 has some threat for tornado today, although the highest risk is expected to be north and east of Grand Island where low-level shear is maximized. Sig-tor parameter (STP) values of 5-7+ are forecast by the RAP/mesoanalysis, which is a quite substantial indicator of tornado potential. A storm or two may approach western areas later this evening, but are expected to weaken as the move into the area in the 8-10pm timeframe. Most of our Nebraska counties should be storm-free by 8-9pm, but southern portions of the area have potential for a longer-duration event, with storms continuing to build near and just north of I-70. If this occurs, localized flooding is possible (mainly Mitchell/Osborne counties), although this will depend exactly on where storms setup. Monday will start off cloudy and relatively cool, with potentially some showers/drizzle in the morning and early afternoon. An additional round of convection is expected to develop along the stalled front. Less of the area is expected to be impacted than today and Saturday, but nevertheless, portions of northern KS, along with the Hwy 81 corridor could see severe storms in the 3-8pm timeframe. A Red Flag Warning remains in effect until 9pm today for southwestern zones that are expected to see a quick burst of dry air behind the dryline this afternoon. After today, the overall fire weather threat is relatively low for the rest of this week. Not much time was spent on the longer-range forecast. Temperatures remain below-normal through midweek, then gradually warm back up into the Memorial Day weekend. Rain/t-storm chances also return to the forecast by the end of next week. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 101 PM CDT Mon May 18 2026 For KGRI/KEAR Airports: MVFR conditions will continue to across the much of the area this afternoon through tonight. Low stratus could could cause to SHRA and DZ for the next few hours. The low stratus will clear west to east late tonight bringing back VFR conditions tomorrow. There is a chance for so TSRA near KGRI this afternoon, but convection will likely stay off to the east. Winds are forecast to remain out of the north through the period. Wind gusts are forecast to diminish tonight, but winds will remain elevated around 14 kts during the overnight hours. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ UPDATE...Stump DISCUSSION...Mangels AVIATION...Stump  299 FXUS63 KGRR 181815 AFDGRR Area Forecast Discussion National Weather Service Grand Rapids MI 215 PM EDT Mon May 18 2026 .KEY MESSAGES... - Severe Line of Storms moving out this evening - More storms on Tuesday - Frost/Freeze Wednesday Night across the North && .DISCUSSION... Issued at 215 PM EDT Mon May 18 2026 - Severe Line of Storms moving out this evening A line of storms that was well forecast by the Hi-Res ARW will be moving across the southern half of the forecast area this afternoon and moving off to the east this evening. Downdraft CAPE values of over a 100 J/kg in the airmass the line is moving through means downbursts with severe wind gusts to 60 mph are the main threat with this line. Scattered storms with isolated severe winds and/or hail are possible across the north. The severe threat winds down this evening as the line of storms moves off the the east with little to no additional QPF expected overnight with the atmosphere being effectively stabilized. - More storms on Tuesday Surface cold front moves southeast across the forecast area on Tuesday afternoon attended by scattered strong to severe storms as surface based CAPE approaches 1500 J/kg. Best chance for severe weather will be across the southeast forecast area where instability is greatest. Deep layer shear greater than 40 knots will also aid the cause. The cold front will move southeast of the forecast area during the evening, ending the threat with a much cooler airmass moving back in. - Frost/Freeze Wednesday Night across the North Canadian surface high building in on Wednesday and Wednesday night with dew points dropping into the 20s and 30s will lead to min temps cold enough for Frost/Freeze headlines across about the northern third or half of the forecast area. Temperatures moderate by the end of the week as low pressure moves up from the south bringing rain by Friday into Saturday. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 215 PM EDT Mon May 18 2026 A line of severe thunderstorms with surface wind gusts to 50 knots will be moving through AZO and BTL between 18 and 19Z and JXN by 20Z. The northern end of the line will clip GRR and LAN with surface wind gusts of 45 to 50 knots possible. The storms this afternoon could bring brief IFR conditions with heavy rain reducing visibilities less than 2 miles. The storms will move off to the east and this evening should see a lull in the thunderstorms until late Tuesday morning or afternoon. LLWS to 40 knots is expected late tonight into Tuesday morning. && .MARINE... Issued at 215 PM EDT Mon May 18 2026 No changes to the SCA. Winds and waves will remain hazardous to small craft through Tuesday. A cold front moves through late Tuesday and northwest winds could gust to 25 knots into Wednesday before diminishing Wednesday night as high pressure builds in. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory from 2 AM to 8 PM EDT Tuesday for LMZ844- 845. Small Craft Advisory until 8 PM EDT Tuesday for LMZ846>849. && $$ DISCUSSION...Ostuno AVIATION...Ostuno MARINE...Ostuno  266 FXUS66 KMFR 181814 AFDMFR Area Forecast Discussion National Weather Service Medford OR 1114 AM PDT Mon May 18 2026 ...New Aviation Section... .AVIATION (18Z TAFs)... VFR conditions are expected at all terminals throughout the valid TAF cycle. Northwesterly flow aloft is anticipated through this cycle as high pressure maintains over the Pacific. Main thing this cycle will be the breezy wind speeds this afternoon, but not expecting these speeds to continue after sunset with speeds decreasing overnight in a typical diurnal fashion. && .PREV DISCUSSION... /Issued 1212 AM PDT Mon May 18 2026/ DISCUSSION...The weather will be quiet with little impact as dry and stable conditions persist this week. With near unanimous agreement across the model suites, forecast confidence is high through Friday with upper level ridging gradually building into our area from the west. High pressure will remain anchored offshore through Wednesday, then build slightly eastward for additional warming on Thursday and Friday, when daytime highs expected to be around 10 or 15 degrees above normal for mid to late May. Slight cooling is possible next weekend or early next week, with a trough expected to move into western Canada. The majority of ensemble members keep the moisture associated with a couple of cold fronts well north of our area, but the second front around Memorial Day could be strong enough and near enough for a marine push and chance of showers for Coos and Douglas counties northward. AVIATION...18/12Z TAFs...Some marine stratus is forming near Cape Blanco this evening and the models have some of that spreading into Roseburg overnight. The boundary layer in some of the models do hint at stratus forming in the Umpqua Basin overnight with IFR ceilings developing for a few hours. Otherwise, those should clear out as we mix out into the day. VFR will prevail in all other areas for the next 24 hours. MARINE...Updated 1200 AM PDT Monday, May 18, 2026...A thermal trough will bring a typical pattern of gusty north winds and steep to very steep seas over the coastal waters much of this week. Winds will be strongest and seas will be highest during the afternoons/evenings. Through this stretch, very steep seas of 10- 12 ft are most likely south of Cape Blanco with steep seas (6-9 ft) north of Cape Blanco. Ensembles indicate winds will strengthen Wednesday into Thursday with a potential (50-70% chance) for gales across portions of the southern waters (especially from around Gold Beach south). && .MFR WATCHES/WARNINGS/ADVISORIES... OR...CA...None. PACIFIC COASTAL WATERS...Hazardous Seas Warning until 11 PM PDT Tuesday for PZZ356-376. Small Craft Advisory until 11 PM PDT Tuesday for PZZ350-370. && $$  398 FXUS61 KRLX 181816 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 216 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... Marginal risk for severe for Tuesday has been expanded slightly to the east. Frontal timing for Wednesday has slowed a little, slightly increasing potential for stronger storms. && .KEY MESSAGES... 1.) Unseasonably hot conditions will continue through Tuesday, with afternoon temperatures peaking in the upper 80s to lower 90s across the lower elevations. 2.) Isolated pulse thunderstorms are possible this afternoon and evening, primarily over the Northeast Mountains. With high downdraft CAPE, collapsing precipitation cores could produce some localized gusty winds. Similar conditions possible tomorrow near the Ohio River in the afternoon with additional thunder chances with a decaying convective complex arriving overnight. 3.) A cold front brings widespread showers and thunderstorms Wednesday. The front stalls to the south and returns as a warm front, setting up a wet, unsettled pattern into the long weekend. && .DISCUSSION... KEY MESSAGE 1... A persistent Bermuda high remains anchored off the Carolina coast promoted subsidence and unseasonably hot conditions across the region. Surface observations at this hour show temperatures already in the mid 80s to 90 degrees across the Metro Valley and southeast Ohio. Afternoon highs will peak in the low to mid 90s today and again on Tuesday, running 10 to 15 degrees above normal daytime highs for this time of year. KEY MESSAGE 2... Visible satellite imagery and surface observations early this afternoon show isolated thunderstorms developing over the higher terrain with an elevated heat source above any weak capping. Analysis of vertical profiles reveal deep layer shear is exceedingly weak, generally under 15KTs. This kinematic profile strongly favors disorganized, pulse-type multicellular convection. While the overall severe threat is low, DCAPE values nearing 1000J/kg combined with steep low-level lapse rates will support a threat for locally gusty downburst winds as precipitation cores collapse. Some isolated tree damage is possible beneath any more robust core collapses. Tuesday will feature another hot afternoon with isolated pop-up showers or thunderstorms possible across the middle Ohio Valley. By Tuesday night, a decaying convective complex is forecast to approach from the west ahead of an advancing cold front although confidence in exact eastern extent is low. Instability will be weakening as any remnants approach the Ohio River, but a marginal threat for gusty winds could persist. KEY MESSAGE 3... A cold front will sweep through the region on Wednesday, providing much needed relief from the heat but bringing showers and thunderstorms. There remains some uncertainty regarding the exact timing of the frontal passage with some guidance showing a slowing trend. A slower frontal passage would allows for greater diurnal destabilization ahead of it; MLCAPE could recover sufficiently to introduce a low-end severe threat, currently none is depicted with the day 3 SPC outlook. Following a brief mainly dry period on Thursday, the frontal boundary will drift back to the north as a warm front, locking the region into an unsettled pattern through at least Sunday. Severe potential appears low through the weekend due to fairly weak flow through the column, but persistent southwesterly flow will continue to transport deep moisture from the Gulf into the region. Given recent very dry ground conditions any rainfall will be largely beneficial. Couldn't rule out some very localized water issues with repetitive slow moving heavy downpours should they hit the same location multiple times as we head into the weekend, but the risk appears low. &&.AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions will largely prevail through the period for most terminals. The main exception will be isolated thunderstorms developing over the higher terrain near EKN this afternoon and early evening. Given the sparse coverage and the disorganized nature of the convection, confidence in direct terminal impacts is too low to include anything beyond VCTS at this time. However, any direct impact could produce brief MVFR/IFR visibility reductions and gusty, erratic winds. Patchy fog may develop at EKN overnight as winds decouple, more likely if any precipitation falls at the terminal this afternoon. Southwest surface winds of 8 to 10KTs, with occasional gusts to 20KTs will persist through the afternoon before decoupling around sunset. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY... FORECAST CONFIDENCE: High. ALTERNATE SCENARIOS: Fog may not develop at EKN if winds do not decouple. Fog may occur much earlier at EKN if any precipitation falls at the field this afternoon/evening. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 17 18 19 20 21 22 23 00 01 02 03 04 EDT 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z TUESDAY... Patchy IFR possible in convection Wednesday and Friday through the weekend. && .CLIMATE... Unseasonably warm conditions continue through Tuesday with some daily record highs potentially being challenged. Forecast / Record High Temperatures -------------------------------------- Mon, 5/18 | Tue, 5/19 | -------------------------------------- CRW | 92 / 92 (1982) | 92 / 95 (1931) | HTS | 92 / 92 (1962) | 91 / 92 (1996) | CKB | 91 / 92 (1962) | 90 / 90 (1959) | PKB | 91 / 95 (1962) | 91 / 90 (1964) | BKW | 86 / 87 (1996) | 87 / 89 (1996) | EKN | 87 / 89 (1911) | 87 / 93 (1996) | -------------------------------------- && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ DISCUSSION...JP AVIATION...JP CLIMATE...JP  365 FXUS65 KPIH 181816 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 1216 PM MDT Mon May 18 2026 .KEY MESSAGES... - Gusty northerly winds diminishing later on today - Best chance of precipitation today across the southeast corner - Frost/freeze conditions through at least midweek before temperatures begin warming up && .DISCUSSION... Issued at 1209 AM MDT Monday May 18 2026 Strong low pressure will continue slowly churn to our south and east today. This will keep a persistent area of light rain and snow, with a few thunderstorms possible across the southeast corner. We could see snow falling at lowest elevations but anything that falls and accumulates should melt later in the day. Across the the higher elevations, a couple of inches are possible. We should also see a few showers across the central mountains south across the Magic Valley and Albion Mountains during the afternoon and evening hours. The bigger overall issue is strong northerly winds, which should be peaking early this morning, but lingering through the day. We do expect some spots to exceed the low end for WIND ADVISORY, but those pocket should be small enough to keep us from issuing something. That said, we are going to easily exceed the northeast wind threshold for American Falls Reservoir, therefore we will keep the LAKE WIND ADVISORY in place for today. The other issue is colder temperatures. We do have a FREEZE WARNING and FROST ADVISORY out for the Snake Plain and Magic Valley this morning. At the moment, the wind is helping keep temperatures pretty warm. However, we are seeing colder air slipping across the Montana border. That, in conjunction with the usual drop in temperatures overnight, we see no need to end the headlines in place for this morning. For tonight, with less wind, we are likely in line for another round of Frost/Freeze headlines. We will also have less cloud cover around. Highs today barely top out above 60 in a few spots. We should see a few showers and potentially isolated storms closer to the Montana border Tuesday afternoon and evening. At the moment, this may be a simple round of virga/sprinkles, but certainly worth mentioning in the forecast. Another wave drops south and east for a better chance of precipitation and thunderstorms Wednesday night and Thursday. We may see a few showers and storms daily heading into the weekend especially closer to the Montana border. Temperatures do eventually starting warming up, heading actually toward AVERAGE through midweek and ABOVE AVERAGE later in the week, as we switch from north/northwest flow to southwest flow. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1210 PM MDT Mon May 18 2026 VFR conditions through the forecast period. Gusty N/NE winds remain in place for the Snake Plain/Teton Valley terminals and these will continue into the early evening before beginning to taper off, becoming more light and variable overnight and into the day Tuesday. KSUN and KBYI will see a more westerly wind component this afternoon and evening and not nearly as breezy as the other locations. Not expecting any precip at terminals through the period with skies becoming more clear into Tuesday. && .PIH WATCHES/WARNINGS/ADVISORIES... Frost Advisory from 3 AM to 9 AM MDT Tuesday for IDZ051-055. Freeze Warning from midnight tonight to 9 AM MDT Tuesday for IDZ052>054. && $$ DISCUSSION...Keyes AVIATION...McKaughan  530 FXUS62 KFFC 181821 AFDFFC Area Forecast Discussion National Weather Service Peachtree City GA 221 PM EDT Mon May 18 2026 ...Afternoon Area Forecast Discussion... .KEY MESSAGES... - Dry conditions will persist through Tuesday. - Warm temperatures continue the next few days with highs in the upper 80s to low 90s. - Increased rain chances return from Wednesday through the weekend, especially in northern and western Georgia. && .SHORT TERM... (This afternoon through Tuesday) Issued at 218 PM EDT Mon May 18 2026 Warm and Dry Weather Through Tuesday: Conditions will be warm and rain-free for most areas through Tuesday, courtesy of a dry airmass surging into the region throughout the day. The one portion of the area that could see isolated afternoon showers and storms each day is across the GA/AL border, where moisture will be a little higher. Elsewhere, PWAT values will drop to below 1 inch, resulting in mostly clear skies outside of high cirrus and some afternoon fair weather cumulus. High temperatures will climb into the upper 80s to low 90s across the region each day, with overnight lows only falling to the low to mid 60s. && .LONG TERM... (Wednesday morning through next Sunday) Issued at 218 PM EDT Mon May 18 2026 The extended forecast period will bring a summerlike pattern by our standards, characterized by warm and muggy conditions punctuated by diurnally-enhanced scattered showers and thunderstorms. PoPs initially begin to trend upward on Wednesday, primarily across north and northwest Georgia, as the Southeast ridge begins to flatten as a weak cold front makes gradual progress southeastward. This front will not make much additional forward progress on Thursday as it becomes stationary across the Tennessee Valley vicinity amid southwest flow aloft. This will keep highest PoPs again concentrated generally along and north of I-20 on Thursday. The front then begins to wash out and lift back northward by Friday as southwest flow aloft persists along the western periphery of the Atlantic ridge. While the ridge looks to gradually expand back westward a bit over the weekend, the deep moisture conveyor within the southwest flow should keep at least scattered convective coverage across at least north and west Georgia, though the bulk of the more consistent rainfall will remain relegated to our west. Obviously, any rainfall is appreciated and welcome at this juncture, though this type of "hit-or-miss" summerlike convection will do little to materially alter the course of the ongoing drought. Temperatures will primarily remain a few degrees above normal, with highs ranging from the mid 80s to lower 90s and lows in the mid-to- upper 60s. && .AVIATION... (18Z TAFS) Issued at 1251 PM EDT Mon May 18 2026 VFR conditions will prevail at most sites through the 18Z TAF period. CU fields of 3-4kft this afternoon may become BKN at times, but will generally remain FEW-SCT. Skies mostly SKC tonight into Tuesday AM, with a low chance for MVFR-IFR CIG development at MCN/AHN around 10-14Z. Winds light out of the S-SE through the period, ranging from 6-8kts during the day and less than 5kts overnight. //ATL Confidence...18Z Update... High on all elements. Culver && .PRELIMINARY POINT TEMPS/POPS... Athens 63 89 65 91 / 0 0 0 10 Atlanta 67 88 68 89 / 0 0 0 30 Blairsville 60 83 62 84 / 0 0 0 50 Cartersville 65 89 65 89 / 0 0 10 50 Columbus 66 90 68 91 / 0 0 0 20 Gainesville 63 87 66 88 / 0 0 0 20 Macon 63 90 66 91 / 0 0 0 10 Rome 63 88 63 87 / 0 0 10 60 Peachtree City 64 89 65 90 / 0 0 0 30 Vidalia 64 91 65 92 / 0 10 0 10 && .FFC WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Culver LONG TERM....RW AVIATION...Culver  493 FXUS63 KARX 181820 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 120 PM CDT Mon May 18 2026 .KEY MESSAGES... - The severe weather threat looks lower for tonight. As a result, the Storm Prediction Center has shifted the Slight Risk further south. The northern extent of the Slight Risk now only extends north to Interstate 90 where before it extended as far north as northeast Minnesota. - Patchy to areas of frost possible in north-central and central Wisconsin on Tuesday night and Wednesday night. && .DISCUSSION... Issued at 120 PM CDT Mon May 18 2026 This Afternoon and Tonight The squall line that moved through our area last night has moved south into the Interstate 70 corridor. South of this line, the temperatures are in the lower 80s and dew points ranging from the mid-60s to lower 70s. With rain cooled air north of this boundary, this air mass will remain south of our forecast area for tonight. As a result, we have seen a reduction in the instability available for the storms along the cold front tonight. Surface-based CAPES which looked to be in the 1500 to 2500 J/kg range yesterday are now only up to 750 J/kg. In addition, the stronger 0-3 km and 0-6 km shear remains post frontal. The CAMs are progressively moving the squall line further and further south. Much of the consensus in the CAMs has this squall line moving east across southern Iowa and northern Missouri. Further north, there are more scattered thunderstorms. This has reduced the severe weather threat because there would be less coalescing of the cold pools. Due to this, we reached out to the Storm Prediction Center and was able to get a more southern shift in the Day 1 Slight Risk. It is now south of Interstate 90. There is now a Marginal Risk from Interstate 90 north into Upper Michigan. If there is severe weather, it would occur between 19.03z and 19.07z. The primary threat would be damaging winds. Tuesday A northern stream shortwave trough will move northeast across western and northern Minnesota and northern Wisconsin. This will result in some scattered morning showers. The strong cold air advection in the wake of the cold front will continue into the day. High temperatures for the day will occur around midnight in the mid- and upper 60s. Temperatures during the day will be in the 50s and 60s. Tuesday Night and Wednesday night The combination of mostly clear to partly cloudy skies and light winds will allow temperatures to fall into the 30s and 40s. There could be the potential for even colder temperatures in central and north-central Wisconsin. This could result in some patchy to areas of frost in our traditional cooler areas of central and north- central Wisconsin. Friday into the Weekend A northern stream shortwave will move slowly east through the region. As this occurs, there will be periodic showers and storms. Like yesterday, both the 0-3 and 0-6 km shear remain less than 30 knots. As a result, the probabilities for organized severe weather look low. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1257 PM CDT Mon May 18 2026 VFR to MVFR conditions currently present across the region with south to southwest winds at or below 12 kts. Most locations currently seeing MVFR CIGs in Southeast Minnesota and Northeast Iowa will likely not see improvement through the afternoon as the stratus deck should persist. Another round of showers and storms is expected to move in from the west/southwest this evening, with impacts at the terminals beginning between 01-03Z tonight. This line will gradually move east with lingering showers continuing into the early morning hours. Widespread IFR CIGs are expected to build in behind the showers for tomorrow morning before gradually lifting to MVFR late in the period. VFR conditions are not expected to return until after 18Z tomorrow. Winds behind the showers will turn to the northwest and pick up to between 10-20 kts with gusts in the 20-30 kt range by late morning. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...Boyne AVIATION...Barendse  568 FXUS64 KSHV 181821 AFDSHV Area Forecast Discussion National Weather Service Shreveport LA 121 PM CDT Mon May 18 2026 ...New DISCUSSION, AVIATION, SPOTTER INFORMATION STATEMENT... .KEY MESSAGES... Issued at 119 PM CDT Mon May 18 2026 - Strong to severe thunderstorms will be possible Tuesday afternoon and evening, particularly across the northwestern ArkLaTex. Large hail, damaging wind gusts and a tornado or two will be possible. - Widespread rainfall will continue on a daily basis for the remainder of the week ahead and into the weekend, potentially leading to flash flooding concerns. - Temperatures will trend below normal as the week continues, due to prolonged cloud cover, with highs in the 80s and lows int he 60s throughout. && .DISCUSSION... Issued at 119 PM CDT Mon May 18 2026 Southwest flow aloft will supply the ArkLaTex with abundant moisture throughout the majority of this forecast period. The next 24 hours or so will see the last genuinely dry portions of this forecast for the region, with only limited slight chances of showers and storms this evening to the southeast and northwest. Today's afternoon highs in the upper 80s and lower 90s will drop into the low to middle 70s by daybreak Tuesday, which looks to get off to a warm, muggy and overcast start. The main event looks to begin tomorrow, as a shortwave trough and attendant surface front swing into the Middle Red River Valley, kicking up our first wave of showers and thunderstorms. Rainfall will return from the northwest, pushing out of southern Oklahoma as early as tomorrow morning, spreading south and east across the entire CWA by midafternoon. As previously advertised, these storms may become strong to severe, with the latest guidance indicating the greatest risk developing during the afternoon hours and continuing into the evening as a cluster of intensifying convection attempts to organize into a squall line as it moves south and east across the ArkLaTex. The principal hazards associated with these storms look to be large hail developing from discrete convection and damaging winds from both isolated clusters and a potential squall line. The threat for tornadoes is comparably low, but cannot be ruled out together, especially in the form of brief rotation developing within a squall line. The organized severe weather threat looks to conclude by late evening Tuesday, but the rainfall will just be beginning. A weak upper level disturbance embedded in the southwest flow will meander very slowly northeast through the middle of the week, as its attendant surface boundary likewise stalls across the region, establishing a firehose of moisture which will be aimed at the ArkLaTex throughout the remainder of the week and into the weekend. This does not look to take the form of continuous rainfall, per se, but frequent enough impulses resulting in high confidence of at least daily rounds of showers. The bottom line is a very wet forecast for the week ahead. The persistent nature of the aforementioned set up is also highlighting the potential for flash flooding. The ArkLaTex is included in at least lower-end risk outlooks beginning tomorrow and continuing through Friday, with the greatest risk currently outlooked on Thursday for our southwestern zones. The most recent accumulation forecast totals suggest at least 3 inches of rain across the region, with the highest totals in the 5 to 7 inch rain. Bear in mind, these totals will be accumulated through the course of the next 7 days. Reinforced by southerly flow, warm conditions will continue, but this wet pattern looks to at least put a dent in the well-above average temperatures of the past few days. Highs will settle into the low to middle 80s by late in the week, with lows in the 60s throughout. /26/ && .AVIATION... (18Z TAFS) Issued at 119 PM CDT Mon May 18 2026 MVFR cigs have lifted/become low VFR across the region as of the start of the 18Z TAF period, and should eventually scatter out across the area by mid-afternoon, with cigs having already scattered out at MLU/ELD. AC cigs also in place across the region early this afternoon should also gradually diminish from W to E by late afternoon/early evening, although cirrus cigs should linger tonight/Tuesday. Low VFR cigs over SE TX should eventually lower by early to mid evening as they begin to spread N across E TX, affecting LFK by 03Z and the TYR/GGG/SHV terminals around/shortly after 06Z. Cigs should gradually lower but remain mostly low MVFR overnight as they affect the remaining terminals prior to daybreak Tuesday, before gradually improving by mid to late morning. VFR cigs should return to much of the region by midday Tuesday, although convection should develop/spread ESE across extreme NE TX/SW AR by late morning/midday, likely affecting the TYR/GGG/TXK terminals by early afternoon, and the remaining terminals by mid/late afternoon into the evening hours. Thus, later TAF issuances will likely include thunder mention for these areas. Strong Srly winds of 11- 17kts with gusts to 22-28kts this afternoon will diminish slightly to 7-14kts with occasional higher gusts to 20kts after 00Z. /15/ && .SPOTTER INFORMATION STATEMENT... Issued at 119 PM CDT Mon May 18 2026 Spotter activation may be needed Tuesday into Tuesday Night. /26/ && .PRELIMINARY POINT TEMPS/POPS... SHV 75 90 71 83 / 20 50 70 90 MLU 74 91 70 84 / 20 40 70 90 DEQ 71 84 65 79 / 30 70 70 80 TXK 74 90 68 82 / 30 80 60 80 ELD 73 90 68 82 / 30 50 60 90 TYR 75 89 69 82 / 30 70 70 80 GGG 75 90 70 83 / 30 70 70 80 LFK 76 91 72 84 / 20 50 70 90 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ DISCUSSION...26 AVIATION...15  737 FXUS61 KALY 181823 AFDALY Area Forecast Discussion National Weather Service Albany NY 223 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... Convective outlook is relatively unchanged at this time, with marginal to slight risk across much of the area on Tuesday and marginal risk for southern areas on Wednesday. Main threat looks to be damaging winds. Hot and humid weather will peak on Tuesday. Heat Risk slightly increased, with some areas in the major category. Some parts of the mid Hudson Valley, Capital Region and NW CT may see heat index values briefly approach 95 during the mid to late afternoon hours on Tuesday. && .KEY MESSAGES... 1) Well-above normal temperatures will continue through the middle of the week. With Heat Risk values in the moderate to locally major category, there is an increased risk for heat- related illnesses, especially on Tuesday. 2) Ahead of a cold front, scattered thunderstorms are expected on Tuesday afternoon and evening, especially for northern areas. Additional storms are possible on Wednesday afternoon, mainly for southern parts of the area. There is marginal to slight risk for storms to be severe, with damaging winds being the main threat. 3) A return to more seasonable temps is expected late this week with the next chance for widespread rain being next weekend. && .DISCUSSION... KEY MESSAGE 1... On Tuesday, southwest flow aloft will continue to allow for 850 hpa to rise to +15 to +19 C across the region. The low-level flow out of the south to southwest will keep the warm and increasingly muggy air mass in place as well. Although dewpoints will initially be in the mid 60s, model soundings shows excellent mixing to about 775-800 mb, which may help lower dewpoints somewhat during the mid to late afternoon hours. Still, a partly to mostly sunny sky and a southwest wind downsloping off the Catskills will allow for a very warm day for mid May, with high temperatures reaching close to record values for the date, with highs in the lower to middle 90s. Heat index values will likely be similar to actual air temps in the mid to late afternoon hours due to the mixing, so the humidity won't be quite mid summer levels. Still, anyone spending time outdoors on Tuesday will need to practice heat safety, especially since it's early in the season and many people aren't used to this extreme heat just yet this year. WPC Heat Risk is still widespread in the moderate (level 2 of 4), although some areas of major (level 3 of 4) are starting to appear for southern areas. It's borderline Heat Advisory criteria, but based on collaboration with neighboring offices, won't go with one just yet due to heat index values mainly below 95 degrees, but it's rather close. With a cold front coming through, most areas will see cooler temps and a drier air mass starting to arrive on Wednesday, although far southern areas will remain ahead of the front for most of the day. A moderate heat risk is still expected for the mid Hudson Valley with highs still approaching 90 by the afternoon hours before the front arrives late in the day. Heat- related illnesses will still be a concern for southern areas on Wednesday. KEY MESSAGE 2... There will be a threat for strong to severe thunderstorms on Tuesday, mainly for northern areas. Our area will on the northern edge of the upper level ridging centered over the eastern seaboard, while an upper level disturbance moves across the Upper Great Lakes. As this disturbance approaches, 0-6 km bulk shear will be increasing through the day, with 30-40 kts across northern areas by the afternoon hours. Although mid level lapse rates will be rather poor to start, they may start to increase by late in the day as the upper level height falls get a little closer to the area. Surface-based instability will besufficient for storms due to the warm and somewhat humid air mass in place, with model values showing about 500-1000 J/kg. CAMs suggest some scattered activity may spread across the Adirondacks and Lake George Saratoga Region beginning in the early to mid afternoon hours and it will spread eastward or southeast for late in the day. Some activity will be possible for the I-90/Capital Region corridor by later in the day as well. 2-5 km updraft helicity isn't overly impressive and CAMs haven't been suggesting much organization, but there should be enough overlap of shear and instability to suggest some storms could be strong to severe. The main threat would be damaging wind gusts with any storm on Tuesday. Some additional storms are expected on Wednesday just along or ahead of the cold front for the afternoon hours. Models suggests there will once again be about 30-40 kts of shear with SBCAPE in the 500-1500 J/kg range. This would primarily impact the mid Hudson Valley, Taconics and western New England. Once again, damaging wind gusts would be the main threats. SPC has a marginal risk for Wednesday and this looks reasonable at this time. Any threat for storms will decrease as the boundary drops north to south across the region, with the front exiting our area by the early evening hours. KEY MESSAGE 3... Behind the front, cooler and drier air will arrive for Thursday into the late week. Daytime temps will only be in the 60s for valley areas for Thursday and Friday. Overnight lows will generally be in the 40s, with some mid to upper 30s possible for the highest terrain of the Adirondacks and southern Vermont. A widespread rainfall is expected over the holiday weekend, although exact QPF, timing and duration of precip is still in question. Models have suggested this could be a slow-moving system, although haven't been consistent on this just yet. With steady rainfall and plenty of clouds, temps could be held down below normal during the rainfall, which may impact holiday weekend plans. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Through 18z/Tuesday...VFR conditions are expected through the TAF period as upper level ridging builds over the region today. Few low level cumulus clouds make there way in from the west but most of the terminals will experience clear skies by late this afternoon/evening. High level clouds begin to move in during the second half of the night. Winds out of the south/southwest this afternoon remain breezy with sustained speeds 5-10 kt and an occasional gust up to 20 kt. Winds then decrease overnight and become light after about 03z. By tomorrow afternoon winds shift more southwesterly and pick back up with speeds 10-15 kt and gusts up to 25 kt. Low level wind shear is expected at all the terminals overnight tonight (after 03z) as surface winds decrease to generally less then 10 kt while winds around 2000 ft AGL increase from the southwest to west at 35-40 kt. Outlook... Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Moderate Operational Impact. Breezy. Chance of SHRA...TSRA. Wednesday Night: Low Operational Impact. Breezy. NO SIG WX. Thursday: No Operational Impact. NO SIG WX. Thursday Night: No Operational Impact. NO SIG WX. Friday: No Operational Impact. NO SIG WX. Friday Night: Moderate Operational Impact. Chance of SHRA. Saturday: High Operational Impact. Likely SHRA. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...Air Quality Alert until 11 PM EDT this evening for CTZ001-013. NY...Air Quality Alert until 11 PM EDT this evening for NYZ063>066. MA...None. VT...None. && $$ DISCUSSION...27 AVIATION...53  751 FXUS62 KCAE 181823 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 223 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... Rain chances for late this week and this weekend continue although coverage could be lower than blended guidance indicates. Aviation discussion updated for 18Z TAF issuance. && .KEY MESSAGES... - 1. Above normal temperatures likely through mid-week. - 2. Rain chances increase late week and into this weekend. && .DISCUSSION... Key Message 1: Above normal temperatures likely through mid- week. Above normal temperatures likely through Thursday with highs in the low to mid 90s expected and no or very little convective coverage each afternoon. PWAT values will be slightly below to around normal through Wednesday so Heat Index values will not rise to advisory thresholds. However, early season heat can contribute to an increased risk of heat-related illness. Key Message 2: Rain chances increase late week and into this weekend. On average, model guidance shifts high pressure eastward late this week, leading to increasing moisture over the Southeast from Thursday through Memorial Day weekend. PWAT values rise to just above normal for the season. However geopotential heights from the NAEFS are also around normal. This would point to a seasonal setup for scattered afternoon convection, possibly enhanced to our north and west with shortwave energy riding over the ridge. PoPs from blended guidance show values above what are climatologically favored and could be too high given the synoptic set up. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions expected the remainder of today with brief restrictions possible again Tuesday morning. FEW to SCT cumulus clouds are being observed across the region with south to southeast winds around 5-10 kts. Occasional low- end gusts are possible this afternoon during peak daytime heating and mixing. Skies are expected to fully clear after sunset as winds weaken and become more variable overnight. Lingering low-level moisture, along with recent HREF and REFS guidance, suggests the potential for fog and low stratus to develop once again tonight mainly after 08-10Z. Model guidance remains somewhat aggressive, similar to last night and this morning, indicating a 40-60% chance of ceilings below 1,000 ft near the typical fog-prone terminals. At this time, periods of MVFR visibility and/or cig restrictions appear most likely between 09-13Z. Trends will need to be watched to determine if more impactful restrictions become likely. After 13-14Z Tuesday, light winds should pick back up out of the south-southeast with clearing skies. EXTENDED AVIATION OUTLOOK...Increased moisture may result in brief restrictions at the terminals due to low clouds and/or fog each day this week. Rain chances increase towards the end of the week. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$ DISCUSSION...CJR AVIATION...ND  694 FXUS63 KDMX 181823 AFDDMX Area Forecast Discussion National Weather Service Des Moines IA 123 PM CDT Mon May 18 2026 .KEY MESSAGES... - Enhanced Risk (level 3 of 5) of severe storms this evening into tonight. Tornadoes, damaging winds, and large hail are also possible as a line of storms moves west to east across the state. The highest probability of severe weather will be from southwestern into central and south central Iowa. - Moderate Risk (level 3 of 4) of flash flooding in extreme southwest Iowa this evening into tonight, with a Slight Risk (level 2 of 4) across the remainder of our forecast area. Flood Watches are in effect from extreme southwest Iowa into adjacent parts of Nebraska and Missouri. - Breezy late tonight into Tuesday, with cooler and drier weather through Wednesday. Lows in the 30s north and west Wednesday morning. - Rain chances return in the latter part of the week, especially around Thursday night and Friday. Warmer weather forecast next week. && .SHORT TERM /THROUGH TUESDAY/... Issued at 122 PM CDT Mon May 18 2026 A deep 500 MB trough is digging across the Rockies and western High Plains this afternoon, with a pronounced vorticity maximum rounding the base and kicking out over eastern Colorado as a negatively tilted shortwave that will move northeastward over NE/IA/SD/MN this evening into early tonight. At the surface, an elongated inverted trough stretches from an attendant surface low developing near the TX panhandle northeastward over Kansas and Iowa, roughly from around Red Oak to Cresco at this time. West of the trough low stratus clouds have socked in the region over northwestern Iowa and adjacent states, with limited insolation reinforcing the developing baroclinic zone/effective cold front, while east of the trough skies are partly cloudy with cirrus also streaming overhead, resulting in limited insolation but combined with south southwesterly flow to promote modest diurnal warming. As the 500 MB trough approaches the region this afternoon, instability will increase to extreme levels over northeastern Kansas where more clearing has occurred, and explosive convection is anticipated in that area. The storms will then propagate and expand northeastward ahead of the trough. Forecast soundings in our area, especially central to southwestern areas, depict very strong instability with CAPE values of 3000-4000 J/KG by late afternoon/early evening, along with strong shear as even 0-500 meter SRH values exceed 200 m2/s2. This environment will support supercells with all severe weather hazards possible including large hail, damaging winds, and tornadoes. However, satellite imagery indicates low-level cloud cover is steady to increasing across much of our area and even into northwest Missouri, and it remains to be seen how much clearing will occur. Short-range mesoanalysis reflects this potential for limited insolation with 0-3 KM CAPE values less than 50 J/KG through the afternoon. This would limit near-surface stretching and may somewhat mitigate tornado potential in much of our area. That being said, if any clearing does reach our area then 0-3 KM CAPE and surface stretching would increase rapidly, supporting a heightened tornado threat. At this time it appears this potential is highest in our southwestern counties and gradually diminishing to the north and east, however, these trends will be closely monitored as the day/evening progresses. Even if tornadoes are limited in our area, elevated supercells progressing into southern and central Iowa this evening would still be capable of producing large hail and damaging wind gusts, and the SPC has maintained an Enhanced severe weather risk across much of our area accordingly. Once the initial round of thunderstorms, forced by the 500 MB trough, exits our eastern/southeastern counties around midnight or so, some elevated showers/thunderstorms will linger overnight but be weaker with more limited forcing and instability, and a rapidly decreasing severe weather threat later tonight. The aforementioned cold front will be exiting our southeastern counties by early Tuesday morning, with any lingering elevated showers or thunderstorms also moving off during the morning. Behind the boundary, northwest winds will surge and bring notably cooler weather across the area. Daytime highs Tuesday will be about 15 degrees lower than today. Meanwhile, gusty northwest winds spreading in behind the front late tonight will continue through Tuesday morning as moderate cold air advection, surface pressure rises, and a relatively tight pressure gradient work through Iowa. Even then, wind potential is limited by the shallow nature of the mixed layer, with forecast soundings indicating top of the ML winds around 25-30 KT during that time. Winds will then slowly diminish during the afternoon as the tighter pressure gradient moves eastward and cold air advection moderates. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Issued at 1250 PM CDT Mon May 18 2026 By Tuesday evening a large surface high pressure area will be building down the northern High Plains and on Tuesday night will settle across Iowa and Minnesota. This will lead to rapidly diminishing winds around sunset Tuesday and much cooler temperatures Tuesday night as winds go light or calm and skies clear out, especially near the Minnesota border closer to the center of the high and where chances for high cirrus clouds are lowest. The result is forecast low temperatures early Wednesday morning in the mid-to- upper 30s in our northern and western counties, but any frost potential will be dependent on skies remaining clear and winds becoming calm. This possibility will be better assessed tonight and tomorrow. From Wednesday through the end of this week a weak 500 MB low will meander across southwestern Canada, with cyclonic flow extending down across the U.S. Rockies and near Iowa. A series of shortwave impulses moving through the flow will result in a return of rain chances for our forecast area. Initially, on Wednesday, the proximity of the slowly departing surface high pressure area and associated dry air will inhibit any precipitation chances. By Thursday atmospheric moisture and instability will be gradually increasing however, and around Thursday night and Friday the most pronounced 500 MB trough will move overhead and bring higher rain chances (50-70%). In wake of that trough, next weekend, weak subsidence may follow along with weak surface riding, supporting mostly dry weather and much lower rain chances (10-20%). Also of note is a consistent signal for some degree of thermal ridging around Sunday into early next week, especially from the EC and GEM, lending confidence to warmer temperatures at the end of the current 7-day forecast. Climate Prediction Center outlooks also support a likelihood of warmer than normal temperatures heading into next week. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1245 PM CDT Mon May 18 2026 Low stratus clouds are producing IFR ceilings across much of northwest IA and MVFR ceilings into central IA early this afternoon. These will eventually spread eastward this evening and tonight ahead of an approaching cold front. Scattered SHRA/TSRA also expected this evening and overnight, with TSRA most likely between about 00Z and 06Z and SHRA more likely thereafter. Have attempted to time convective trends and maintained targeted TEMPO groups for TSRA, but expect updates/amendments later today. Widespread low ceilings around FL007-012 then expected later tonight, with winds turning to NW and increasing behind the front. && .HYDROLOGY... Issued at 122 PM CDT Mon May 18 2026 Trends in flash flood tools suggest an increased risk of flash flooding from activity this evening into tonight. NWM rapid onset flooding (ROF) probabilities suggest the greatest risk will be across our southwest CWA. Soil moisture in that area is elevated due to heavy rainfall over the past few days. Heavy rainfall tonight may lead to flash flooding due to decreased soil capacity, or sheer rainfall intensity, or both. Main concerns will be in towns, however lower areas including road dips near creeks and small streams may see some issues as well. In addition, any flooding will occur mainly during the nighttime hours, which adds to its potential danger. For these reasons, we issued a flood watch for some of our southern counties through Tuesday morning. Longer term, widespread river flooding is a minimal concern this week. Some moderate to significant within-bank rises are possible, however, especially in southern Iowa due to the combination of recent and potential future heavy rainfall. && .DMX WATCHES/WARNINGS/ADVISORIES... Flood Watch from 5 PM CDT this afternoon through Tuesday morning for IAZ092>095. && $$ SHORT TERM...Lee LONG TERM...Lee AVIATION...Lee HYDROLOGY...Zogg  732 FXUS66 KPQR 181823 AAA AFDPQR Area Forecast Discussion...UPDATED National Weather Service Portland OR 1123 AM PDT Mon May 18 2026 Updated aviation discussion. && .SYNOPSIS...Dry and benign weather is expected across the region through much of the next week as high pressure builds over the Northeast Pacific, bringing a warming trend. Weak systems aloft may bring enhanced cloud cover on some days, but rain chances are minimal. && .DISCUSSION...Now through Sunday...A weak upper level disturbance passing over the region this morning will maintain high level clouds through late morning, before skies become mostly sunny this afternoon. Concerns for hazardous weather remain minimal through the next week. There is high confidence that upper-level ridging and surface high pressure will build over the Northeast Pacific, with increasing uncertainty in the amplitude and position of the upper ridge later in the forecast. Early in the period, while the ridge is centered well offshore, upper shortwaves within northwesterly flow aloft may produce increased cloud cover, but chances for rainfall remain 5% or less through the middle of the week. On clearer nights, areas of fog are most likely to develop within sheltered valleys. As the ridge axis shifts east, temperatures will trend upward through at least Thursday, reaching the 60s along the coast and upper 70s to around 80 degrees along the I-5 corridor. Later in the forecast period, uncertainty in the evolution and possible break-down of upper-level ridging introduces a similar uncertainty in forecast temperatures. Highs are most likely to continue in the 60s to mid 70s, but the spread of possible outcomes becomes wider: chances of reaching 80 degrees along the I-5 corridor are generally 15-45% Friday and Saturday, but there are also 10-25% chances of remaining below 70 degrees. The next opportunity for widespread rain holds off until late next weekend when there is greater consensus that the ridge breaks down. 36/DH && .AVIATION...High pressure will maintain fair conditions with high level clouds moving overhead through the day. Northwest flow of 5-10 kt through the day with wind gusts along the coast up to 20 kt possible. Winds relax this evening and overnight. Marine stratus pushed back toward the coast this evening, mainly along the northern Oregon and southern Washington coast. Probabilities increase to 60-90% for development between 02-06z Wednesday for KAST and much lower at 20-30% for KONP. Guidance suggests stratus developing along the Columbia River toward the Portland/Vancouver Metro between 10-1z Wednesday. KPDX AND APPROACHES...VFR conditions expected through at least 06z Tuesday. High clouds expected to clear out this afternoon. Light northwest winds expected to increase to 8-10 kt by 22z this afternoon. Stratus pushing inland along the Columbia River could reach the metro between 10-16z Tuesday with a 30-60% chance for sub-VFR CIGs, mainly for KTTD and KPDX. -19 && .MARINE...Northerlies are expected to persist through much of the week as the summer-like pattern settles in. Strongest winds are expected during the afternoon and evening periods as a surface thermal trough strengthens over the southern Oregon coast. A Small Craft Advisory has been issued for the inner coastal waters south of Cape Foulweather later this afternoon into this evening for gusts up to 25 kt. Similar conditions are expected on Tuesday. Seas around 6 to 8 feet are expected through the week as well. Small Craft Advisories are in place for the Columbia River Bar early this morning, and again early Tuesday morning, for strong ebb currents which will produce hazardous conditions to small craft. Strong ebb currents are possible during the morning hours each day this week. /DH && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory from 5 AM to 9 AM PDT Tuesday for PZZ210. Small Craft Advisory until 11 PM PDT this evening for PZZ253. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland  826 FXUS63 KAPX 181824 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 224 PM EDT Mon May 18 2026 .KEY MESSAGES... - Slight risk for severe thunderstorms this afternoon. - Marginal risk for severe thunderstorms on Tuesday. - Sharply cooler weather arrives Wednesday and Thursday, with frost/freeze concerns Tuesday night through Thursday night (especially on Wednesday night). && .DISCUSSION... Issued at 1207 PM EDT Mon May 18 2026 Pattern Synopsis/Forecast: Moisture rich warm sector spreading northeast across the Great Lakes this afternoon as deep layer southwest flow continues between southeast Conus ridging and deep troughing rotating across the Intermountain West. Showers and thunderstorms beginning to percolate across northern Lake Michigan along decaying cold pool convergence (from overnight convection to our west). Surface based warming and attendant northward expansion of over 500 joules/kg of mixed layer cape within marginally supportive convective layer shear should continue to allow intensification of this activity as it races east across our area. Deep upstream troughing will continue to lift northeast, steadily shearing out as it crosses into southern Canada and the northern Great Lakes later Tuesday into Tuesday night. Attendant cold front expected to cross our area on Tuesday, with additional showers and storms expected to fire in the pre-frontal warm sector until its crossing. Sharply cooler airmass follows this passing wave, setting the stage for additional frost/freeze concerns for the middle of the week. Primary Forecast Concerns: Shower/storm evolution and severe potential through Tuesday. Secondary focus on just how cold we become through the middle of the week (those frost/freeze concerns). Details: Expect upscale growth to convective activity as it quickly slides northeast across our area the remainder of this afternoon. Combination of instability, those marginal convective layer shear profiles, and expected congealing cold pool dynamics should support some isolated severe potential, with gusty winds and marginally severe size hail the primary concerns. However, slightly backed low level wind fields down near Saginaw Bay will also support a very low risk for tornadoes as well. Loss of surface based instability should end the most aggressive shower/storm concerns quicky early this evening. Focus for most numerous storms and greatest severe potential focuses off to our west tonight in vicinity of primary wave and attendant east advancing cold front. May see some of this decaying activity slide into our area later tonight/early Tuesday morning. Not expecting anything too significant with this activity as surface rooted instability core is lost by then. Cold front will work steadily east across our area on Tuesday...exiting off to our east by early Tuesday evening. Front becomes increasingly detached from any large scale support, though moisture rich pre-frontal environment and forced low level convergence will continue to support shower and storm generation. Severe potential tied to just how much heating/surface rooted instability generation can occur prior to frontal passage. Think ongoing showers and cloud cover may limit this potential, with focus for severe storms centering to our south and southeast. SPC maintains just marginal severe weather potential across northern lower Michigan...themselves focusing on pre-frontal destabilization concerns. Focus quickly shifts to the arrival of a much cooler airmass as Canada originated high pressure drops into the western Great Lakes Tuesday night into Wednesday. Simple breadth of cold air advection looks to drop temperatures down into the 30s across a good portion of the area Tuesday night, although maintenance of gusty northwest winds will likely prevent much freeze or frost concerns. A chilly Wednesday...when some areas will likely not get out of the 40s...gives way to what is shaping up to be a cold Wednesday night. Pattern recognition definitely supports such, with high pressure centering directly overhead supplying what should be clear skies and light/calm winds...all within an already exceptionally chilly airmass. Widespread lows well down into the lower and middle 30s looks easily attainable, and fully believe some of our traditional colder interior areas will make a run into the 20s. Definitely something to monitor given our recent warm temperatures. Conditions modify some Thursday and Thursday night, but could still see more frost and potential freeze concerns early Friday morning. Current trends support slow moderation through the weekend, with readings at least approaching more normal levels on Sunday. Other than the chill, extended period looks far less active, with perhaps some better rain chances returning during the weekend. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 216 PM EDT Mon May 18 2026 Showers and thunderstorms to continue through this evening, with occasional +TSRA and wind gusts 25 to 35 KTs possible within the strongest storms. CIGs decrease through the evening as well, with MVFR and IFR tonight (occasional LIFR as well for some). BR possible tonight as well, especially where moist and rainy conditions from this afternoon manifest. Likely turn MVFR for much of Tuesday with isolated thunderstorm chances. Southwest winds will be breezy to gusty tonight and especially through Tuesday. && .APX WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory from 8 AM Tuesday to midnight EDT Tuesday night for LHZ345>349. Small Craft Advisory until midnight EDT Tuesday night for LMZ323-341-342-344>346. Small Craft Advisory from 8 AM Tuesday to midnight EDT Tuesday night for LSZ321-322. && $$ DISCUSSION...MSB AVIATION...JLD  836 FXUS64 KMRX 181824 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 224 PM EDT Mon May 18 2026 ...New DISCUSSION... .KEY MESSAGES... Updated at 224 PM EDT Mon May 18 2026 - Very warm temperatures for Tuesday with highs 10 to 15 degrees above nromal. - Increasing chances for showers and storms return Wednesday. Scattered showers and thunderstorms are expected each day from Thursday through the weekend especially across the higher elevations. && .DISCUSSION... Issued at 224 PM EDT Mon May 18 2026 Main weather feature through Tuesday night will remain an upper ridge over the southeast United States into the southern Appalachians. Main impact will be mostly dry and unseasonably very warm temperatures. Highs will be 10 to 15 degrees above normal. Near record highs anticipated. For Wednesday, ensemble cluster analysis shows a short-wave trough moved east of Great Lakes and upper Ohio valley. This wave will weaken the upper ridge over the region and allow a frontal boundary to approach the area. Lower heights and better PWs will allow for increasing chances of showers and thunderstorms especially over the Plateau counties. Instability with remain marginal with CAPES of 1000-1500, mid-level lapse rates of 6 degrees or less with little to no shear. At this time severe storms are not anticipated. For Thursday, frontal boundary remains near the region with PWs of 1.5-1.7 inches so moisture returns over the area. Depending where frontal resides (GFS suggests across northeast Tennessee and southwest Virginia) that is where the highest chances of convection will be. Instability and shear remain limited with little to no severe threat, but fairly good coverage of showers and storms with much needed rainfall. QPF for Wednesday through Thursday will range from 0.10 to 0.50 inch. For Friday, frontal boundary lifts north as an upper trough/jet moves northeast into the mid-west and Ohio valley producing pressure falls there. The increase in southerly boundary jet will pull frontal boundary north. Plenty of moisture and instability remains so scattered showers and thunderstorms developing into the afternoon especially across the terrain features. For Saturday through Monday, the southern Appalachians will remain with plenty of moisture and afternoon instability with an upper trough across the southern Plains. This upper trough will slowly move toward the Tennessee valley. Ensembles and deterministic models show better instability with possible short-waves ejecting out the trough across the region. There is a greater threat of stronger afternoon storms during this period. && .AVIATION... (18Z TAFS) Issued at 108 PM EDT Mon May 18 2026 VFR conditions will prevail throughout the forecasts. Winds will be gusty up to 20 kts possible this afternoon and Tuesday afternoon. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 68 89 68 88 / 0 10 10 70 Knoxville McGhee Tyson Airport, TN 67 90 68 88 / 0 0 0 30 Oak Ridge, TN 66 88 65 86 / 0 0 10 60 Tri Cities Airport, TN 62 89 63 87 / 0 0 0 40 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...DH AVIATION...DH  818 FXUS65 KGJT 181824 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 1224 PM MDT Mon May 18 2026 .KEY MESSAGES... - Mountain snow continues through this evening. A Winter Weather Advisory remains in effect for the eastern Uinta, Elkhead, and Park Mountains. - Freezing temperatures are expected to impact the lower basins of northwest Colorado and northeast Utah Tuesday and Wednesday morning. Freeze highlights are in effect. - Temperatures will start to warm Tuesday onward, finally reaching near-to-above normal levels Thursday and Friday. && .DISCUSSION... Issued at 1223 PM MDT Mon May 18 2026 COOLER AND WETTER WEATHER: The cold front has finally pushed through most of eastern Utah and western Colorado, with a significantly cooler airmass filling in. Temperatures today will run 15-25 degrees below normal, feeling more like March than May. The widespread rainfall that accompanied the frontal passage is transitioning to a more convective mode this afternoon, although limited instability will keep a lid on thunderstorm development. Look for gusty winds and light to moderate rainfall with showers this afternoon. Snow showers will also be possible at the higher elevations, and Winter Weather Advisories remain in effect for the Eastern Uintas and Park and Elkhead ranges through this evening. Activity will taper off this evening as drier air works in under northwesterly flow. This will also lead to skies clearing from west to east, resulting in freeze concerns, discussed below. After a cold start tomorrow, temperatures start to rebound as flow aloft turns southwesterly and warm air advection kicks in. That said, we remain below normal tomorrow and Wednesday, before finally reaching late- May norms on Thursday. Light mountain showers will be possible each afternoon, but otherwise conditions will be quiet and mostly sunny. The next chance for precipitation comes late in the week, as a quick- moving wave clips northeastern Utah and northwestern Colorado. FREEZE POTENTIAL: With cold air advection ongoing and skies expected to clear out tonight, freeze potential remains a concern. The coldest conditions will occur on Tuesday morning. The Yampa River Basin and the eastern Uinta Basin are most likely to see sub-freezing temperatures by daybreak tomorrow, though the Yampa Basin is most likely to see a hard freeze. Freeze Warnings are in effect for these zones from midnight tonight through 10AM tomorrow morning. Wednesday morning will also likely see sub-freezing temperatures in the Yampa River Basin, thus a freeze watch has been issued for CO001 and CO002. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1124 AM MDT Mon May 18 2026 Rain and snow showers continue to impact much of the region this morning. Cigs at KASE, KEGE, KRIL, KTEX, and KHDN are expected to be below ILS breakpoints through most of the afternoon. Precipitation could drop vis to MVFR conditions or lower at higher elevation terminals. Gusty winds are also expected to persist through the early evening, reaching 20-30 knots at most terminals. By 00Z, most storms will have cleared out, and VFR conditions should be restored region-wide by 06Z at the latest. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...Freeze Warning from midnight tonight to 10 AM MDT Tuesday for COZ001-002. Freeze Watch from late Tuesday night through Wednesday morning for COZ001-002. Winter Weather Advisory until 9 PM MDT this evening for COZ004. UT...Freeze Warning from midnight tonight to 10 AM MDT Tuesday for UTZ024. Winter Weather Advisory until 6 PM MDT this evening for UTZ023. && $$ DISCUSSION...BGB/TGJT AVIATION...TGJT  971 FXUS63 KLSX 181826 AFDLSX Area Forecast Discussion...Updated Aviation National Weather Service Saint Louis MO 126 PM CDT Mon May 18 2026 .KEY MESSAGES... - Widespread showers and thunderstorms are expected throughout the day with heavy rainfall in some locations potentially leading to flash flooding. - A few strong to severe thunderstorms are possible this afternoon and evening with the main hazards being hail and damaging wind gusts. - Additional thunderstorms are forecast late tonight and early Tuesday morning with another round possible along a cold front Tuesday afternoon/evening. && .SHORT TERM... (Through Late Tuesday Afternoon) Issued at 402 AM CDT Mon May 18 2026 A complex of thunderstorms, that as of 09z, is currently positioned near Quincy MO to Warrensburg MO. This activity initiated across KS/NE on Sunday evening and has continued to push southeastward early this morning, with arrival in central/northeast MO expect around 09-10z. Within the last few hours, this complex has become outflow dominant, which has led to a gradual weakening trend from the severe wind gusts it was producing across northwestern MO around midnight. Upstream observations indicate that the gust front has been achieving winds gusts in the 30-50mph range. As a result, the main severe hazard tied to these storms as they move into the area are expected to be scattered wind gusts up to 50mph, along with frequent lightning and heavy rain. In fact, one of the main concerns regarding the short term is now the threat for heavy rainfall and flash flooding, mainly across central/south-central MO and points west. CAMs are in good consensus that the southeastward progress of this thunderstorm complex will continue to slow as it makes its way into the area this morning. Additionally, there are signs that backbuilding of thunderstorms may occur as the remnant outflow boundary/line of convection stall in a west-east orientation, with strong low-level southerly warm/moist advection overrunning this stationary boundary. Analysis of forecast soundings unveils a plentiful amount of uniform CAPE (around 1,500 J/kg) throughout the column, along with warm cloud temperatures with freezing levels around 12-14kft AGL. In addition, PWATs are currently in the 1.4-1.5" range, with the latest HREF indicating values increasing to 1.7-1.9" today, which is near the 99th percentile. Lastly, the HREF LPMM precipitation reveals the potential for a west-east oriented swath of 2-4" with localized pockets of 4-6" possible. Given all of the variables mentioned above, the risk of heavy rainfall has prompted us to issue a Flash Flood Watch for central/south-central MO and portions of east- central MO that is in effect from 12z today through this evening. Regarding the severe weather potential throughout the day, the threat remains for an isolated thunderstorm becoming strong/severe with hazards being hail along with damaging winds. This potential appears to be lower due to the lingering showers and thunderstorms across a large portion of the area, inhibiting solar insolation, and thus, robust destabilization this afternoon. Regardless, given the warm/moist summerlike airmass in place and the continuation of steepened mid-level lapse rates, maintaining sufficient instability, the threat for an isolated severe storm remains. A few locations may be able to clear by this afternoon, allowing the environment to recover and destabilize, and potentially the threat for strong to severe thunderstorms to increase in localized areas. With uncertainty regarding the evolution/coverage of lingering showers/storms, confidence is low regarding the extent of severe weather that may be realized across the area this afternoon and evening. By tonight, the large-scale pattern features a broad mid/upper level trough to the west, with an embedded shortwave ejecting northeastward into the Great Plains. This mid-level feature triggers lee-side surface cyclogenesis across the Central Plains/Midwest near a quasi-stationary baroclinic zone. Convection is modeled by high resolution guidance to initiate along this boundary in KS/NE, with quick upscale growth ensuing with eastward progression. The surface low is modeled to lift northeast into the Midwest on Tuesday, which begins to slowly shift the quasi-stationary baroclinic zone southeastward as a cold front. However, this convection is progged by guidance to outrun this slowly advancing cold front out west, and gradually weaken as it approaches the area. This weakening trend appears reasonable since the best deep-layer shear remains displaced to the north and west of the area and forcing for ascent will be limited without convection tied to the boundary. Regardless, this threat for severe weather late Monday night into early Tuesday morning will include the potential for large hail and damaging wind gusts. Additionally, if surges or bowing segments occur, then severe outflow gusts or embedded circulations leading to brief tornadoes may also be possible. Guidance is in fairly good agreement that the cold front will approach northeast MO/west-central IL Tuesday morning with it exiting to the southeast late Tuesday evening. Locations that remain pre-frontal for a majority of the day on Tuesday will have the greatest severe weather threat. The big question that remains is, how quickly will the atmosphere recover from the early Tuesday morning convection by the time the front is working its way through the area. As of now, it appears the severe weather threat will be greatest from east-central MO and points southeastward, as these locations will have the best chance to destabilize in the early afternoon on before the arrival of the front. Regardless, instability and mid-level flow are still forecast to be sufficient enough to support organized storms with potential for large hail, damaging winds, and tornadoes. Any lingering outflow boundaries from morning convection may serve as areas of focus for thunderstorm development in the afternoon ahead of the cold front. Peine && .LONG TERM... (Tuesday Night through Sunday) Issued at 402 AM CDT Mon May 18 2026 Low-level cold air advection within the post-frontal airmass will lead to much cooler conditions for Wednesday, with highs forecast to be around 10-15 degrees below average. Quasi-zonal flow aloft encompasses the region through the end of the week, which should allow for a period of dry conditions until Friday. By the end of the week, the general trend of LREF temperature IQRs is a gradual warmup to temperatures right around climatological normals. Peine && .AVIATION... (For the 18z TAFs through 18z Tuesday Afternoon) Issued at 101 PM CDT Mon May 18 2026 A complex of showers and thunderstorms continues across central Missouri this afternoon. This round of thunderstorms has persisted since the overnight hours with almost continuous thunder at the TAF sites (except KUIN) since 12z. The line of thunderstorms has stalled just south of KCPS this afternoon with a shortwave wave currently near the Arkansas/ Missouri border. The shortwave is causing additional thunderstorm development just north of the boundary (or close to Columbia, MO). This means that all terminals will likely (>90% chance) observe thunderstorms through the remainder of the afternoon into the early evening. As the shortwave moves northeast of the region, showers and thunderstorms will begin to finally move east of the terminals with thunder temporarily ending from west to east. This break will be brief though. Another line of showers and thunderstorms will approach the terminals from the northwest Tuesday morning between 4 and 7 AM. This line of storms will likely weaken as they progress southeast, but the question is how quickly will they weaken. As of current, the thinking is the line of thunderstorms will hold together long enough to make it to KUIN, KCOU, and KJEF. It is unclear if there will be thunder at the St. Louis terminals. For now have only added SHRA (no thunder) for KSTL, KSUS, and KCPS. A cold front will then cross the terminals Tuesday afternoon with MVFR/ IFR cigs behind. BAH && .LSX WATCHES/WARNINGS/ADVISORIES... MO...Flood Watch until 7 PM CDT this evening for Boone MO-Callaway MO- Cole MO-Crawford MO-Franklin MO-Gasconade MO-Jefferson MO- Lincoln MO-Moniteau MO-Montgomery MO-Osage MO-Saint Charles MO-Saint Louis City MO-Saint Louis MO-Warren MO-Washington MO. IL...Flood Watch until 7 PM CDT this evening for Bond IL-Clinton IL- Fayette IL-Madison IL-Marion IL-Monroe IL-Saint Clair IL- Washington IL. && $$ WFO LSX  440 FXUS61 KCAR 181831 AFDCAR Area Forecast Discussion National Weather Service Caribou ME 231 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... Added small hail and gusty winds in storms for Tuesday Lowered lows for Friday night. && .KEY MESSAGES... 1) Warm to very warm with a chance for thunderstorms Tuesday and Wednesday afternoon. A few stronger storms are possible. 2) Below average temperatures are expected Thursday and Thursday Night. Near freezing temperatures are possible early Friday morning across the north, which may require actions to protect vulnerable plants. && .DISCUSSION... KEY MESSAGE 1... Warm to very warm with a chance for thunderstorms Tuesday and Wednesday afternoon. A few stronger storms are possible. KEY MESSAGE 1 DESCRIPTION... A little shortwave ahead of a larger trough will drape a warm front over the area that moves north through the day Tuesday. This warm front will bring warm temperatures and instability. Some cloud cover could prevent increased daytime heating which could limit convection. Thunderstorm chances are highest in central and south Maine. Storms may contain gusty winds and potentially small hail and lightning. The risk of a tornado cannot be ruled out. The models have significantly slowed down the progression of the cold front through the region, with it now progged to move through mainly on Wednesday night. This is due to the front being almost parallel to the winds aloft as well as subsidence under the ridging exiting to the east on Wednesday. As a result, Wednesday likely will be the warmest day of the week across most of eastern and south central Maine. Because of this, models are now keying on convection firing mainly along/just north of the sea breeze front over Downeast Maine and into the Bangor region. With around 1000 J/kg of CAPE, 40-50kt of Bulk Shear, could see strong to locally severe storms across this region, with the main threat being strong gusty winds and hail. The tornado threat remains non- zero, with Energy Helicity Index of 0.5 to 1, 0-3km SRH 100-175 m2/s2 and 0-1km SRH 50-100 m2/s2. However the threat is much lower than on Tuesday. Also of note on Wednesday is that the winds should be rather gusty with gusts of 30-35 mph, with some peak gusts to around 40 mph across the Saint John Valley. Highs on Wednesday should run 15-20 degrees above normal. With Dewpoints peaking out around 60, and falling off in the afternoon, this should limit apparent temperatures to the upper 70s to lower 80s across most of eastern and central Maine, with low-mid 70s across the North Woods. KEY MESSAGE 2... Below average temperatures are expected Thursday and Thursday Night. Near freezing temperatures are possible early Friday morning across the north, which may require actions to protect vulnerable plants. KEY MESSAGE 2 DESCRIPTION... NW flow in the low levels advects in a much cooler air mass into the region Thursday into Thursday night, as Canadian High pressure builds in from the northwest and west. This high then builds over the area through Friday night. The result will be lows running 5-10 degrees below normal both nights. This should result in frost mainly across Northern Maine. Zones 2, 5, 6, 10, 11, 31 and 32 get added to the frost freeze program on May 21, so a frost advisory could be needed for at least part of that area on both nights if current forecast trends hold. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Tonight...VFR for all terminals except for KBHB, which could reach IFR in some marine fog. LLWS possible at northern terminals. Some rain showers at far northern terminals. SW winds at 5-10 kt and gusts to 15 kt. Tuesday...MVFR, potentially lower in terminals with severe thunderstorms. Best chance for thunderstorms is during the afternoon into evening. Heavy rain, lightning, small hail, and gusty winds are possible in these thunderstorms. S wind at 5 kt shifting to W winds at 5-10 kt. Gusts to 20 kt. Tuesday night...MVFR possible at northern terminals, IFR possible at KFVE. VFR elsewhere. Some rain showers at northern terminals possible. WSW winds 5 to 10 kt, ramping up through the night, with gusts to 20 kt. Wednesday: Low chance of MVFR early at northern terminals, otherwise VFR. Tempo MVFR/IFR is possible at southern terminals in any strong convection. W-WNW winds G25-30KT likely with a chance of gusts to 35KT at far northern terminals. Wednesday night-Saturday: VFR. NW winds G20-30KT possible during the day Thursday and Friday. && .MARINE... Winds stay below SCA criteria Monday night, with some gusts of 25 kt on outer waters Tuesday out of the southwest. Some fog is possible Monday night. Rain showers and some thunderstorms are possible on Tuesday. Marginal Small Craft Advisory seas around 4 to 6 feet are possible over the coastal ocean waters Tuesday night. Wave heights to around 5 to 7 feet along with gusts up to 25 kt are possible across the outer waters. Small Craft conditions are likely across the coastal waters Wednesday through Thursday, with gusts of 25-30kt and seas of 4-6 ft over the outer waters during this time frame as well. From Thursday night through Saturday, sub-SCA conditions are predicted for the coastal waters and winds less than 25 kt and seas of 5 ft or less are forecast for the outer waters. There is a small chance for some strong thunderstorms over the coastal waters Wednesday afternoon and early Wednesday evening. Sea surface temperatures remain very cold, but are beginning to moderate into the mid 40s. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...None. && $$ DISCUSSION...TF/PM/JS AVIATION...TF/PM/JS  407 FXUS63 KSGF 181831 AFDSGF Area Forecast Discussion National Weather Service Springfield MO 131 PM CDT Mon May 18 2026 .KEY MESSAGES... - A Moderate Risk (3 out of 4) for thunderstorms with heavy rainfall that may result in flash flooding this afternoon and another round overnight. A Flood Watch in effect for an area north of Interstate 44 towards the Highway 54 corridor. Additional rainfall amounts of 1-3 inches. - A Slight Risk (2 out of 5) for a few strong to severe thunderstorms this afternoon. Primary hazard is damaging wind gusts and large hail to the size of quarters. - A Slight Risk (2 out of 5) for severe thunderstorms overnight tonight into Tuesday. A line of thunderstorms expected to quickly move through the area, with the primary hazard being damaging wind gusts. There is a lower chance for a few, brief tornadoes. - Additional rainfall chances (40-70%) mid to late week along with cooler temperatures. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 100 PM CDT Mon May 18 2026 Current Conditions and Synoptic Overview: Water vapor and upper air analysis shows southwest flow aloft with a strong shortwave over Colorado. There is a compact shortwave currently moving into Arkansas. While the low level jet has weakened, it remains out of the southwest around 35-40kts over the area. An outflow boundary from overnight storms was beginning to wash out however it remains west to east from about Barton County east/northeast to Phelps county. A moist and unstable airmass continues over the area with the 12Z sounding measuring 2500j/kg MU CAPE and 0-6km shear around 30kts. Thunderstorms continue to develop along and north of that outflow boundary, especially in the Flood Watch area. Temperatures varied drastically with 60s along/north of Highway 54 to lower 80s further south. Thunderstorm/Flood Threat This Afternoon: Latest meso trends and 12z HREF/REFS supports continued development of scattered thunderstorms this afternoon over the northern half of the area. Given the CAPE/Shear combo, a few severe storms are possible with large hail and damaging winds the most likely hazards. Flash flooding will be a concern in the Flood Watch area, especially locations that have received several inches of rainfall already. There should be a decreasing trend in storm coverage closer to 6-9pm. Round of thunderstorms Overnight/Tuesday: Confidence is high that significant severe storms will develop in Kansas this afternoon and evening along a cold front and an area of high shear and high instability. The storms look to quickly grow upscale into a QLCS and will expand southwest towards Oklahoma. Latest guidance suggests that the QLCS will move southeast and enter our southeast Kansas and western Missouri counties shortly after midnight. ML CAPE around 1500j/kg and 0-3km shear around 30kts will allow for the potential for damaging winds to be the most likely hazard as this line of storms moves southeast through the area. We will need to monitor for any line segments that can surge/pivot to the east-northeast as there will be a potential for a brief tornado, especially locations west of Highway 65. There remains uncertainty with respect to the exact timing of the line as it moves through the area however it should be along the I-44 corridor in the 4am to 8am time frame. The instability levels will continue to decrease overnight therefore an overall weakening trend seems likely as storms move southeast of I-44 early Tuesday morning. Additional rainfall amounts of 1-3 inches is possible with the storms overnight. We did extend the Flood Watch until 18Z Tuesday to account for the next round of rainfall. The remainder of Tuesday is uncertain as there are questions about how fast the front moves through the area during the day. There are a few CAMS that suggest that storms intensify during the afternoon, mainly southeast of I-44. Large hail and damaging winds would be the most likely hazards if storms redevelop/intensify Tuesday afternoon. Considerable uncertainty exists with additional updates likely. Temps will also begin to fall quickly behind the front with 60s in some areas by late Tuesday afternoon. Additional post frontal showers look likely Tuesday evening as additional energy moves through the area. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Issued at 100 PM CDT Mon May 18 2026 Additional Rain Chances/Cooler Weather Mid/Late Week: Ensemble data continues to suggests that the overall upper level pattern west/southwest with several disturbances moving through the region. The front that moves through Tuesday looks to stay south of the area Wednesday however given the flow, additional precip chances are possible south of I-44. The front does appear to attempt to lift north into the area Thursday and persist through Saturday. Precip chances currently from the NBM are rather pessimistic with chances greater than 50% at times, especially closer to Thursday and Friday. Currently not seeing a signal for severe storms or flooding. Temps will remain cooler than previous days, especially Wednesday with slowly climbing temps closer to 80 degrees by the weekend. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1230 PM CDT Mon May 18 2026 Scattered showers and thunderstorms will be in and around the TAF sites this afternoon, especially JLN and SGF. Otherwise ceilings around 3000ft will be likely this afternoon. Winds will likely remain out of the south with gusts around 25-30kts. Low level wind shear is likely at SGF and JLN overnight. There will be a line of thunderstorms that moves into the area after 08z and continues through Tuesday morning. Confidence is increasing that winds will turn west to northwesterly towards the end of the TAF period along with ceilings dropping into at least MVFR. && .SGF WATCHES/WARNINGS/ADVISORIES... KS...None. MO...Flood Watch until 7 PM CDT this evening for MOZ055>058-066>071- 078>081. && $$ SHORT TERM...Burchfield LONG TERM...Burchfield AVIATION...Burchfield  331 FXUS64 KOUN 181830 AFDOUN Area Forecast Discussion National Weather Service Norman OK 130 PM CDT Mon May 18 2026 ...New NEAR TERM, SHORT TERM... .KEY MESSAGES... Updated at 126 PM CDT Mon May 18 2026 - There is a risk for strong to severe thunderstorms this afternoon through Tuesday. - Critical fire weather conditions are possible for far western Oklahoma into western north Texas this afternoon - Very warm temperatures are expected today with cooler weather by Tuesday. && .NEAR TERM... (Rest of today and tonight) Issued at 126 PM CDT Mon May 18 2026 Windy with potential fire weather across our far west and severe risks for storms are the headlines for today and tonight's period. The strong low-level jet overnight is not expected to weaken too much today as we could see wind gusts in the 40-50 mph as we continue to mix higher into the jet. A deepening surface low lee of the Colorado Rockies will maintain a tight pressure gradient across our area with south winds sustained at 20-25 mph. As a result our current Wind Advisory will remain in effect through this evening in areas generally west and north of the I-44 corridor. A dryline approaching our western CWA is expected to advance across the western one-tier of our counties in Oklahoma and adjacent northern Texas. As a result the fire danger potential will be increasing Near Critical to Critical risk west of the dryline due to very low afternoon RH's expected along with the gusty south winds and hot temperatures over still dry vegetation. A Red Flag Warning will be in effect this afternoon into the evening hours in that one-tier of counties west of the dryline. As far as storms, there is a 20-25% probability for convection firing up along and east of the dryline as forecast soundings suggest diurnal heating eroding the mid-level cap. Should any storms initiate they would be growing in strongly unstable (3000- 5000 J/kg) environment. Although deep-layer shear may be weak this afternoon in our area but expected to increase tonight along with the low-level shear as the low-level jet strengthens. Although the overall highest severe risk will be highest across the Central Plains the risk will extend into the Southern Plains with an Enhanced risk across northern Oklahoma to a Slight risk covering all but our far southeast CWA. Should any dryline convection initiate there is a potential for supercells producing large hail and damaging wind gusts and a conditional risk for a tornado with that risk highest closer to the Central Plains in northern Oklahoma. Storm POPs increase late tonight up to 80% with a cold front coming down the Central Plains advancing into northern Oklahoma late this evening pushing across the remainder of our forecast area through the early morning hours. Todays severe risks and associated hazards will be remain unchanged for tonight in the warm sector along and ahead of the cold front as the shear will be increasing. && .SHORT TERM... (Tuesday through Wednesday night) Issued at 126 PM CDT Mon May 18 2026 By sunrise Tuesday expecting the cold front & storm activity to be near the I-44 corridor and continue pushing south and east. Storm POPs will remain high up 60-90% along the front during the remaining morning hours but more restricted to southeast Oklahoma in the afternoon with the cold front eventually exiting our area. The severe risk remains along the cold front into Tuesday afternoon with the hail & wind hazards remaining although the tornado risk will be very low. High surface pressure starts building in behind the cold front with lighter north winds advecting much cooler air down through the Great Plains. Although the coolest air may lag reaching southeast Oklahoma and our Texas counties for a day, the remainderof our area will see milder unseasonably cooler temperatures with highs near 70 degrees with the muggy air restricted to southeast Oklahoma. Although our area will be post-frontal by Tuesday evening, the main systems upper trough will remain opened across the western U.S. through this week with a series of short-wave disturbances expelled downstream over the Southern Plains each day producing elevated-based convection. The first of these disturbance will increase storm chances Tuesday evening and overnight across our area. Although the ECMWF is less aggressive with the elevated instability, the NAM suggests these elevated storms could produce severe hail & winds overnight. For Wednesday all of our area will feel milder with highs in the lower to mid 70s becoming chilly with overnight lows in the 50s to low 60s and storm chances again increasing overnight. && .LONG TERM... (Thursday through Sunday) Issued at 315 AM CDT Mon May 18 2026 An active subtropical jet stream (STJ) with subtle waves lifting into the Southern Plains will result in a daily chance of showers/storms through the end the week into next weekend. At this time, there is no day that has an appreciable risk for severe weather. Temperatures are expected to be seasonable for late May. Mahale && .AVIATION... (18Z TAFS) Issued at 1204 PM CDT Mon May 18 2026 Scattered to broken low clouds have mostly lifted to VFR ceiling heights, but a few sites could see MVFR ceilings off and on through mid afternoon. Very low storm chances exist this afternoon into this evening across western OK and western north TX, but better chances are expected along a cold front that will cross the area tonight into Tuesday morning. Expect gusty south winds to continue ahead of the front through this evening, with a shift to gusty northerly winds and MVFR ceilings behind the front. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 61 70 55 71 / 60 40 60 30 Hobart OK 60 72 54 73 / 60 20 50 20 Wichita Falls TX 68 81 58 76 / 20 80 70 40 Gage OK 49 72 46 70 / 20 0 10 10 Ponca City OK 58 69 52 70 / 80 20 30 10 Durant OK 74 84 64 78 / 10 90 60 50 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...Wind Advisory until 10 PM CDT this evening for OKZ004>027- 034>038. Red Flag Warning until 9 PM CDT this evening for OKZ004-009-014- 021-033-034. TX...Red Flag Warning until 9 PM CDT this evening for TXZ083-084. && $$ NEAR TERM...68 SHORT TERM...68 LONG TERM....10 AVIATION...08  383 FXUS66 KSTO 181830 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1130 AM PDT Mon May 18 2026 .KEY MESSAGES... - Red Flag warning expires this evening. - Less wind rest of the week but above normal temperatures returning with widespread moderate heat risk Thursday. && .DISCUSSION... ...Tonight and Tuesday... The upper trough/inside slider that brought us widespread gusty winds is quickly moving off to the east and causing severe weather in the central U.S. This will shift upper winds from the north to a more zonal westerly directions. In other words, less wind for the rest of the week. Relative humidities will remain low this week but not as dry as today. Once the pattern settles in on Tuesday/Wednesday it looks to stay pretty consistent. Warmest day looks to be on Thursday with very little spread in maximum temperature in the NBM percentiles. Currently looks like widespread moderate heat risk with temperatures in the 90s to approaching 100 in the north. Confidence pretty high that temperature forecast shouldn't change too much. HeatRisk probabilities very low to reach above moderate risk but will keep an eye on this. Things look to cool down enough Friday into the weekend but still very warm. No rain in site right now in the 7 day forecast. && .AVIATION... VFR conditions are expected over the next 24 hours. Northerly winds 15-20 kts with gusts 20-30 kts for the Valley and Delta until around 00z-03z Tuesday. Northeast to east wind gusts up to 20-35 kts through mid-day today. && .STO WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 8 PM PDT this evening for Butte County Below 1000 ft-C. San Joaquin County including Stockton-C. Solano County including Fairfield-C. Stanislaus County including Modesto-C. Yolo/NE Solano including Woodland-Central Colusa County Incl. I-5-Central Glenn Co & Interstate 5-Eastern Colusa County-Eastern Glenn County-N. Sac Valley in Tehama County-NE San Joaquin Valley Below 1000 ft-SW Solano County including Vallejo-Sac Metro/W. El Dorado/Amador County-Sacramento County Delta-San Joaquin County Delta-Shasta Metro-Sutter/Yuba counties below 1000 ft-Tracy Triangle Below 1000 ft-W. Stanislaus County Above 1000 ft & I-5-W. Yolo County including Capay/I-505. && $$  585 FXUS64 KMEG 181831 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 131 PM CDT Mon May 18 2026 ...New DISCUSSION, AVIATION, FIRE WEATHER... .KEY MESSAGES... Issued at 131 PM CDT Mon May 18 2026 - Hot and humid conditions are expected through Tuesday, with high temperatures reaching or exceeding 90 degrees in many locations. - Widespread showers and thunderstorms will return to the forecast by Tuesday afternoon, with a low confidence severe weather threat. The main concerns with any strong to severe thunderstorm would be damaging wind gusts and large hail. - Chances for showers and thunderstorms will persist daily beginning late tomorrow through the remainder of the upcoming week. && .DISCUSSION... (This evening through next Sunday) Issued at 131 PM CDT Mon May 18 2026 This morning's upper air analysis depicts an upper level ridge over portions of the Carolinas and the Southeast U.S. with an upper-level trough located over the Rockies. Southwest flow aloft is present from the Southern Plains up to the Mississippi Valley and Great Lakes Region. Latest surface analysis places a surface low over southern Minnesota with a weak cold front trailing southwest into the Central and Southern Plains. A warm and humid atmosphere is in place across the Mid-South with 12 PM temperatures in the 80s. Regional WSR-88D radar trends show a small cluster of showers and thunderstorms over portions of northeast Arkansas. This convective activity is associated with a subtle, but weak mid- level shortwave trough moving across portions of the Middle Mississippi Valley. Latest mesoanalysis yields surface-based CAPE values around 2000 J/kg, with weak mid-level lapse rates and overall shear generally less than 20 kts. Short-term CAMs indicate a low chance (20-30%) for showers and thunderstorms north of I-40 towards the MO/KY border into this evening but confidence remains low with the overall coverage in the weakly sheared environment. Short-term models continue to indicate a weak cold front dropping into the Lower Mississippi Valley on Tuesday. Upstream showers and thunderstorms are expected to weaken as they move into the Lower Mississippi on Tuesday. This convective activity will eventually produce outflow boundaries, which will provide a focus for afternoon convection. Shear is expected to remain weak with best upper-level support remaining displaced to the north. Thus, convective development is expected to occur mainly during the mid/late afternoon during peak heating with a mostly unorganized pulse type convective mode. Overall confidence remains low with the severe thunderstorm potential on Tuesday with the threat waning by early Tuesday evening with the loss of daytime instability. Mid to long range models indicate this front will remain stalled out across the area through late week. Precipitable water values will remain high around 1.75 inches with any heavy rainfall threat remaining localized in the absence of any appreciable upper-level support. This boundary is anticipated to retreat north as a warm front with rain chances continuing into the weekend, especially during peak heating. Temperatures will remain near normal through most of the period. && .AVIATION... (18Z TAFS) Issued at 131 PM CDT Mon May 18 2026 A low chance for MVFR ceilings will exist around sunrise Tuesday at MEM and TUP and wasn't included in TAFs due to low confidence. Otherwise, VFR conditions are expected to persist through most of the period at TAF sites. An approaching cold front will provide a focus for isolated to scattered shower and thunderstorm development mainly late Tuesday afternoon. A PROB30 has been introduced at MEM for 20-24Z. Conditions still remain favorable for marginal LLWS at JBR later tonight. Elevated south winds are expected at most sites throughout the period with gusts confined mainly to daytime hours. && .FIRE WEATHER... Issued at 131 PM CDT Mon May 18 2026 No major fire danger concerns for the foreseeable future, with minRH values remaining above 40%. Multiple rounds of showers and thunderstorms will move across the Mid-South beginning on Tuesday through the remainder of the week. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...CJC AVIATION...CJC  811 FXUS62 KCHS 181833 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 233 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... All sections were updated. && .KEY MESSAGES... - 1) Minor coastal flooding is possible along coastal areas of Charleston and Colleton Counties with high tide this evening and possibly Tuesday evening. - 2) Rain chances likely to increase late in the week, though no hazardous weather is anticipated at this time. && .DISCUSSION... KEY MESSAGE 1: Minor coastal flooding is possible along coastal areas of Charleston and Colleton Counties with high tide this evening and possibly Tuesday evening. Astronomical influences associated with the recent new moon and lunar perigee along with a modest onshore flow will continue to drive elevated tide levels, potentially leading to minor coastal flooding along parts of the lower South Carolina coast this evening. The latest forecast advertises a peak high tide 7.0-7.2 ft MLLW in the Charleston Harbor this evening and 6.9-7.1 ft MLLW Tuesday evening. A Coastal Flood Advisory for Coastal Colleton and Charleston Counties could be needed for this evening's high tide and possibly again Tuesday evening, although confidence in reaching the 7.0 ft MLLW minor flood stage is much more uncertain by then. Astronomical tide levels then begin to fall and the potential for minor coastal flooding will diminish. KEY MESSAGE 2: Rain chances likely to increase late in the week, though no hazardous weather is anticipated at this time. The synoptic pattern is forecast to shift slightly during the latter half of the week, bringing a more unsettled weather regime to the region. While finer details remain uncertain, most guidance indicates shortwave energy rounding the northwestern periphery of an upper ridge Wednesday into Friday. At the surface, a cold front is expected to drop southeastward across the Great Appalachian Valley late Wednesday before potentially stalling across the Carolinas and later lifting into the Northeast U.S. as a warm front by Saturday. The approach of this boundary will promote increasing moisture and rain chances across the region. However, the eventual placement and southward progression of the front will play a key role in determining where and how much precipitation occurs. Notably, the latest ensemble guidance indicates a 20-50% probability of accumulated rainfall exceeding one inch, with the highest probabilities currently focused inland. In terms of severe weather potential, the latest solutions favor the deeper moisture and thus greater instability to remain to our north. Additionally, weak forcing and shear will keep the potential for severe weather low during this latter portion of the week. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... 18/18z TAF Discussion: KCHS/KJZI/KSAV: VFR. Gusty winds will occur with the passage of the sea breeze this afternoon. Shallow ground fog will be possible again at all terminals early Tuesday morning. Extended Aviation Outlook: There are no high confidence concerns. && .MARINE... Through Tonight: The synoptic flow regime will change little through tonight as Atlantic high pressure remains centered well offshore. An easterly flow regime will prevail with east to southeast winds 15 kt or less prevailing. Some local enhancement could occur along the land/sea interface and Charleston Harbor this afternoon with the sea breeze. Seas will average 2-4 ft. Tuesday through Saturday: No marine concerns are expected. High pressure to the east will drive onshore east-southeasterly flow each day, with wind speeds mostly topping out in the 10-15 knot range. Each afternoon and evening there could be some local enhancement along the land/sea interface with the diurnal sea breeze. Seas should average 2-4 feet through the period. Rip Currents: Influences from the new moon cycle combined with persistent onshore flow will produce an elevated risk of rip currents. A moderate risk for rip currents is in place for all beaches through Tuesday. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ BRS  890 FXUS64 KEWX 181835 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 135 PM CDT Mon May 18 2026 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... - Low chance for a few showers and storms today mainly along the Rio Grande - Line of strong to severe storms with locally heavy rain possible Tuesday evening/night. - Active weather pattern from mid-week through the upcoming Memorial Holiday weekend. Heavy rain at times could lead to localized flooding. && .SHORT TERM... (Tonight through Tuesday night) Issued at 133 PM CDT Mon May 18 2026 The cap should continue to hold this afternoon, but sufficient warming could spark isolated storms along the Rio Grande in the evening which may push east if they do develop. While only the 12Z HRW ARW and FV3 CAMs depicted deep convection developing in this manner out of the HREF suite, the moist and buoyant environment does increase the background potential relative to typical expectations, so storm chances this evening are but were adjusted higher than the NBM mainly over the Rio Grande Plains and southern Edwards Plateau. The low-level jet that delivered several days of abnormally breezy and humid conditions will continue for another night (albeit with slightly reduced strength), imparting southerly gusts in the 20-30 mph tonight. The upper-air disturbance over the Central Plains that enabled the LLJ is actively moving farther away, so we expect that winds will start to gradually subside tomorrow. Humid air will likely persist through the week, but lows Tuesday morning should cap off a streak of mornings with near-record to record-setting mild temperatures. A weak cold front will slowly crawl south towards our local area throughout the day. This front arrives without the support of northerly winds aloft, so this won't be a front known for its northerly post-frontal winds or brisk arrival. Instead, the interaction of the front with the humid airmass stockpiled over our area should produce scattered to widespread shower and storm activity, with that action encroaching upon the Hill Country by the evening hours. Additionally, southwesterly divergent flow aloft should produce isolated to scattered thunderstorms along the dry line atop the higher terrain over Mexico, which may move east towards the Rio Grande and join up with the front. A steady cap should be able to generally mute storm development over South-Central Texas for most of morning and afternoon Tuesday. Despite the clouds and moist air, highs in the 90s with the ample humidity should again boost heat indices above 100F for portions of the Rio Grande Plains and Coastal Plains, with values in the mid to upper 90s elsewhere. However, as the front and dry line get active and move closer, rain chances go up quickly after sunset and temperatures should begin to fall off more than they have on previous days. The primary period of storminess Tuesday is likely from Tuesday evening into the overnight hours. The SPC has highlighted a Level 2 of 5 (Slight) risk of severe weather with the greatest risk generally along and west of the I-35 corridor. While the simulated radar outputs from the hi-res models disagree in the general arrangement of storms Tuesday evening, the overall environment with weak mid-level flow along the front supports a line of thunderstorms along the front pushing south over the area. There's a somewhat emergent model consensus that this line could reach the Hill Country / Edwards Plateau near or just before sunset and then progress south through the rest of our area before winding down in the pre-dawn hours Wednesday, not too unlike our line of storms last week. The primary severe threat would likely be isolated strong to damaging wind as storms ripple along the front. There could be some isolated large hail potential mainly over the Edwards Plateau, but the rather modest effective bulk shear (generally under 30 kt) and high freezing level will generally limit that risk to only the strongest updrafts. The heavy rain potential will also need to be monitored as well as the front brushes up against the moist, accumulated Gulf air. The WPC has up to a Level 2 of 4 (Slight) risk for isolated heavy rain capable of flash flooding across a substantial portion of our warning area, and the generally weak flow aloft and thick warm cloud depth could support more efficient downpours. Storms that manage to develop ahead of the front would find themselves briefly in a slow-moving environment and add to this rain. This signal is slightly higher in the southern Hill Country Rain totals will generally depend on how quickly the rain-cooled air pushing the line of storms kicks into gear, but the overall prospects for widespread amounts above 1 inch looks likely. A few localized pockets of 3-5" of rain is also hinted at by the CAMs, and this would be commensurate with the moist environment. While the severe risk is more established for northern portions of the CWA, the geographic placement of the heaviest rains is a little more uncertain. && .LONG TERM... (Wednesday through next Monday) Issued at 133 PM CDT Mon May 18 2026 Tuesday's front will likely be pushed along by the rain-cooled air from Tuesday night's storms, and Wednesday morning should start out more seasonably with temperatures in the 60s to low 70s. The medium-range model guidance shows several protuberances of vorticity aloft moving over our area Wednesday. However, the atmosphere will probably take some time to recuperate from the preceding night's storms, and even with the moist airmass remaining in place it would not be a surprise to spend most of the day Wednesday rain-free. Still, the continued presence of moisture and a conducive southwesterly flow persisting aloft thanks to broad troughing over the western US means that there will be more opportunities for rain and storms throughout the week. Heavy rain potential will continue with precipitable water values repeatedly near or over the 90th percentile for this time of year. Key elements to watch will be any residual boundaries left over by previous rounds of storms, which can be foci for new storm development, and bundles of vorticity aloft moving over the area to enhance certain windows of opportunity for rain. The precise timing and placement of storms will be based on these factors, which will be sensitive to the evolution of each successive period of storms. Based on their depictions of mid-level 700mb vorticity, a few of the medium-range models, including the GFS, ECMWF, and their ensemble suite and AI counterparts suggest a favorable period for rain Thursday. The WPC has up to a Level 2 of 4 (Slight) risk for heavy rain during that window. Another conducive period may take shape this weekend. This timing should be considered with broad brushstrokes, as it's still too early to decipher which areas may see heavier rains and when. However, taken altogether, there could be a gradually increasing potential for flash and riverine flooding as each round of rain saturates grounds further. The bottom line is that an active and wet pattern looks likely for the entirety of South Central Texas through the week. Continue to check back as details get clearer over the coming days. && .AVIATION... (18Z TAFS) Issued at 1249 PM CDT Mon May 18 2026 Cigs are either MVFR or will trend to MVFR within the hour at area TAF sites. Otherwise, some isolated convection may develop near DRT late this afternoon or early evening. With coverage limited, we will not mention any convection in the forecast at this time. Low clouds and MVFR cigs will return by mid-evening along I-35, with DRT seeing these cigs closer to 09Z. Gusty south to southeast winds will persist through the period. We will need to monitor for a line of convection approaching AUS near or just beyond the end of the current 30 hour forecast period. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 77 90 71 85 / 10 30 80 60 Austin Bergstrom Intl Airport 79 90 71 85 / 10 30 70 60 New Braunfels Muni Airport 77 90 70 85 / 10 20 70 60 Burnet Muni Airport 75 86 67 82 / 10 40 80 60 Del Rio Intl Airport 76 93 71 88 / 20 20 50 40 Georgetown Muni Airport 77 88 69 83 / 10 40 80 60 Hondo Muni Airport 78 90 70 84 / 10 20 70 60 San Marcos Muni Airport 78 91 71 85 / 10 20 70 60 La Grange - Fayette Regional 78 90 72 85 / 10 20 70 60 San Antonio Intl Airport 78 91 71 85 / 10 20 70 60 Stinson Muni Airport 79 92 71 86 / 10 10 70 60 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Tran LONG TERM....Tran AVIATION...Platt  964 FXUS62 KTBW 181836 AFDTBW Area Forecast Discussion National Weather Service Tampa Bay Ruskin FL 236 PM EDT Mon May 18 2026 ...New DISCUSSION, AVIATION, MARINE, FIRE WEATHER... .KEY MESSAGES... - Above normal temperatures are expected each day through the next week. - Thunderstorms are expected to develop each day this week, mainly in the afternoon to early evening hours. - Severe to extreme drought conditions continue for most areas. && .DISCUSSION... Issued at 230 PM EDT Mon May 18 2026 Our summertime convection looks to be getting starting for the early part of the week with increase moisture and an active seabreeze. Our flow will generally be out of the east through Wednesday. This will favor west coast showers and storms during the afternoon and evening hours with inland area mainly staying dry. As we head into Thursday and Friday we will see an upper level low move into the northern Bahamas. The first thought would be this will increase shower chances. However the low actually shifts our upper level winds more northerly bringing a little bit of drier air and keeping storms chances pretty limited (20 to 30%). The only exception with be Southwest Florida where we still keep some high moisture along with high storm chances. As we head into t upper level flow switches to the southeast and the weekend moisture comes back with PW reaching around 1.75. This will allow for scattered showers and storms with the highest chances still along the west coast. However, the higher PW will still bring some storms in inland locations mainly in the afternoon hours. && .AVIATION... (18Z TAFS) Issued at 230 PM EDT Mon May 18 2026 Newest hi res model guidance showing moisture increasing slightly along the west coast this afternoon. Because of this we have introduced a prob30 group for both TPA and PIE. Sites south of that will be seeing a VCTS as storm chances will be higher the farther south you go. Winds will be out the east with occasional gusts up to 20 knots. && .MARINE... Issued at 230 PM EDT Mon May 18 2026 Winds will be mainly out of the east for much of the week around 5 to 15 knots with winds shifting southeast on Friday. Our main concern to boaters will be afternoon and evening storms that push off of land and and into the Gulf. Some of these storms could cause frequent lightning and strong winds. && .FIRE WEATHER... Issued at 230 PM EDT Mon May 18 2026 Increased moisture with summertime convection will help to minimize fire hazards this week. Highest rainfall totals during this week should be along the coast with inland areas staying mostly dry. && .PRELIMINARY POINT TEMPS/POPS... TPA 92 75 91 74 / 30 30 60 20 FMY 93 74 93 74 / 60 10 60 10 GIF 92 73 91 72 / 20 0 30 10 SRQ 93 73 93 73 / 50 30 70 20 BKV 94 70 94 69 / 20 10 40 10 SPG 94 75 94 75 / 40 30 70 20 && Sea Breeze Thunderstorm Regime For Tuesday: 3 Sea Breeze Thunderstorm Regime For Wednesday: 2 For additional information on sea breeze regimes, go to: https://www.weather.gov/tbw/ThunderstormClimatology && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ DISCUSSION/AVIATION/MARINE/FIRE WEATHER...Shiveley DECISION SUPPORT...Close UPPER AIR/CLIMATE...Close  106 FXUS65 KRIW 181839 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 1239 PM MDT Mon May 18 2026 .KEY MESSAGES... - Snow and wind (up to 60 mph) remain for portions of central and southern Wyoming, including around Lander, Casper, South Pass, and Interstate 80. Conditions should slowly improve through he remainder of the day, with any light precipitation ending by midnight. - Warming trend Tuesday and Wednesday, with mostly dry conditions. Another weather system brings cooler temperatures and precipitation chances for Thursday. - Currently looking favorable for warm and dry weather this coming holiday weekend. && .UPDATE... Issued at 1235 PM MDT Mon May 18 2026 The snow and wind across the area has been mostly as forecasted. Greatest impacts were around South Pass and I-80, with winter travel impacts going into this afternoon. Conditions should slowly improve through the evening as snow decreases and winds diminish. As was the trend in the day leading to the start of the event, northern locations have not seen as much (or any) snow, so have ended the advisories there early. As the system exits, very cold temperatures remain in place, with lows tonight in the upper teens to mid-20s for a majority of the area. Cooler temperatures remain in place Tuesday and Tuesday night, with a very gradual warm up into the end of the week. && .DISCUSSION... Issued at 240 AM MDT Mon May 18 2026 Rain changed over to snow in the Wind River Basin and across Sweetwater County just a few hours ago after 11pm Sunday night. Much of Natrona County is around 37F degrees as of 08Z (2am), with precipitation still falling as rain. The forecast remains on track this morning, with the threat of snow and wind impacting areas from South Pass southward into Sweetwater County. The 700mb low from this storm system will be passing close to the CO/WY border this morning, resulting in a tight temperature and pressure gradient. 700mb northeast winds of 50-60kt will occur from the Green Mountains/Rattlesnake Range into Sweetwater County. This will result in wind gusts of 60 to 70 mph occurring this morning over locations like South Pass down to the Rock Springs/Green River area. Windy conditions (wind gusts up to 35 mph) will be widespread across the CWA this morning as the storm system moves over CO this morning. Snowfall amounts of 2 to 6 inches is still expected across portions of Natrona County, the Lander Foothills and the eastern half of Sweetwater County. Travel conditions could be difficult this morning due to the blowing snow and icy roads. Impacts from snow accumulations on roads is likely to only last through 15Z/16Z (9am or 10am) as it will be more difficult for the snow to stick due to the high sun angle. These impacts will begin to decrease through the morning, with areas like Lander and Casper improving first as snow begins to end toward midday. Impacts along I-80 will last the longest due to the proximity of the 700mb low, but is expected to wane between 18Z and 21Z as snowfall ends. Winds will be decreasing across the area after 18Z as well, with the stronger winds of 35 to 40 mph continuing from South Pass southward into Sweetwater County and decreasing through the afternoon. Needless to say, temperatures will be anywhere from 5 to 25 degrees colder today and about 15 to 30 degrees below normal. Winds will continue to decrease this evening, as the storm system quickly exits over the Central Plains and light winds (10kt or less) expected for most areas by 06Z Tuesday. Fog development could occur as late as sunrise Tuesday morning as clouds are expected to remain in place across central and southern portions of the CWA through much of the night tonight. Dry and warming conditions are expected Tuesdayand Wednesday, with another Canadian storm system impacting the area on Thursday. This system doesn't look to be as cold as today's storm and snow levels staying around 7000ft at this time. Model guidance remain split at this time, but confidence is medium for a mainly dry holiday weekend for at least 2 of the 3 days. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1235 PM MDT Mon May 18 2026 A spring system will continue to impact the area this afternoon, now focused mostly east of the Divide. KCPR, KLND, and KRIW will hold on to MVFR to IFR conditions for the next few hours before conditions begin to improve as the system pushes east. However, additional showers are expected to develop across the western mountains, impacting KBPI and KPNA this afternoon and evening with IFR flight conditions. This is expected to largely remain farther south and east of KJAC. Activity should wane everywhere after 06Z Tuesday, with clouds decreasing from west to east overnight. If skies clear quick enough fog may be an issue at several terminals after around 10Z. For now, we are most confident at KBPI and KRKS, though fog potential will also need to be watched for at KCPR, KLND, and KRIW. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .RIW WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 6 PM MDT this evening for WYZ014- 016-017-026>029. Winter Storm Warning until 6 PM MDT this evening for WYZ015- 018>020-022-030. && $$ UPDATE...Wittmann DISCUSSION...LaVoie AVIATION...Myers  202 FXUS63 KLMK 181841 AFDLMK Area Forecast Discussion National Weather Service Louisville KY 241 PM EDT Mon May 18 2026 .KEY MESSAGES... * Today through Tuesday, temperatures are expected to warm into the mid 80s to low 90s. Some daily max temperature records could be challenged. * This afternoon/evening, showers and/or thunderstorms arrive, especially for our northwestern counties. This is mainly a wind and hail threat. * A line of strong to severe storms is expected to move through ahead of a cold front on Tuesday, possibly bringing strong winds and hail. The line will weaken as it moves east over the region. * More active weather arrive later this week as multiple rounds of showers and scattered thunderstorms are possible going into Memorial Day weekend. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 241 PM EDT Mon May 18 2026 Current mesoanalysis shows 2000-2500 J/kg of uninhibited SBCAPE, about 20kts of deep layer shear, and steep lapse rates. Not seeing much agitated Cu over our CWA just yet, but just to the west, we have seen some initiation. Shear will slightly increase as the MCS approaches the CWA, which will help storms to become slightly more organized. Over the next few hours do expect some scattered strong to severe storms, with a wind and hail threat. The threat area will be small, over southern Indiana and just along the Ohio River. Most of the region will be spared of any storms. Additionally, PWATs near 1.8-2.0 inches and a slowly moving line of storms will allow for heavy rainfall. This line is also moving aprallel to the LLJ, which will allow for training. Due to this, there is also a risk for heavy rainfall to lead to some minor flooding issues over our far northwestern areas in southern Indiana. As the sun sets, we will quickly lose instability. Showers and storms are expected to quickly dissipate. With broken sky cover and light southerly winds, not expecting a great radiational cooling night. Low temperatures will likely remain warm in the upper 60s and low 70s. This will be close to warm minimum records for May 18. Ahead of an approaching cold front, WAA will continue to keep temperatures in the upper 80s and brushing 90. This will help SBCAPE to increase near 3000J/kg. Dew points will also creep into the upper 60s and low 70s. Though shear will remain low around 20kts. Pulse summertime thunderstorms will be possible in the afternoon prior to the cold front and association line of storms. When the cold front approaches, we are expecting a decaying line of storms to outrun the best forcing along the cold front. Wind and hail will be the main threat on Tuesday over the northwestern 2/3rd of the CWA. The cold front will begin to slow its progression southward Tuesday night, making it through most of the CWA by Wednesday morning. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Issued at 241 PM EDT Mon May 18 2026 As the cold front slowly sags the the south on Wednesday, widespread showers and scattered thunderstorms are expected, especially for the southern half of our area. Rich moisture along the front will help fuel these showers and storms, with LREF PW values ranging from 1.4- 1.7" (>95th percentile climatologically). Instability to the south of the front will also help fuel these showers, with LREF mean SBCAPE around 750-1000 J/kg. The wind shear profile is very meager, so we don't currently expect severe weather at this stage. With the front moving through, temperatures will much closer to normal for this time of year, with highs in the mid-to-upper 70s north of the front in southern Indiana and northern Kentucky, and highs in the low 80s south of the front in south central Kentucky. The front stalls out just south of our area by Thursday, but with some moisture still in place over our far southern counties chances for showers will be possible (35-50%). With northerly flow at the surface, temperatures across the region will be slightly cooler than Wednesday, with highs in the low-to-mid 70s. Though an area of surface high pressure tries to build in over the Great Lakes and Ohio Valley regions Thursday, a broad upper level trough over the western CONUS pushes eastward and drives the high out of the area. Ahead of the trough axis, a series of shortwaves surges northeastward, lifting the frontal boundary northward Thursday night. Considerable southerly flow at the surface and aloft will allow deep moisture to surge back northward, helping set up a few decent periods of showers and some thunderstorms into Memorial Day weekend. The southerly flow will also allow temperatures to rise back up into the 80s by the weekend, but with dew points again in the mid 60s, it will also feel rather muggy outside. The more active pattern for rounds of showers is currently expected to last through the end of the forecast period, so a little bit of drought relief may finally be on the way. && .AVIATION /18Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 127 PM EDT Mon May 18 2026 VFR conditions are expected for central Kentucky through this forecast period. Currently, FEW Cu clouds are streaming over eastern Kentucky and convective debris clouds are moving into southern Indiana and northern Kentucky. Gusty winds out of the SSW will continue through the afternoon. A decaying line of showers and storms will enter southern Indiana in the next few hours. This will mostly impact southern Indiana and far northern Kentucky. Storms will begin to dissipate as the sun sets. Gusty winds will pick back up out of the SSW on Tuesday morning. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...None. IN...None. && $$ SHORT TERM...SRW LONG TERM...BEN AVIATION...SRW  156 FXUS64 KFWD 181840 AFDFWD Area Forecast Discussion National Weather Service Fort Worth TX 140 PM CDT Mon May 18 2026 ...New SHORT TERM, LONG TERM, AVIATION... .KEY MESSAGES... - Isolated showers and thunderstorms are possible again this afternoon, but most areas will stay dry. - More widespread showers and storms are expected Tuesday and Wednesday as a cold front moves into and stalls across the region. Heavy rainfall and some strong to severe storms are possible both days. - Daily chances for scattered showers and storms will continue the rest of the week into the weekend. Locally heavy rain will be possible but the severe weather threat appears low. && .SHORT TERM... (This evening through Tuesday) Issued at 139 PM CDT Mon May 18 2026 A warm, humid, and windy afternoon is underway across North and Central Texas as strong southerly flow continues ahead of a dryline to our west and a cold front moving into the Southern Plains. The special 18Z sounding still shows a sizable cap in place, which should suppress most convective attempts through this afternoon. Increasing broad-scale lift may still allow an isolated shower or storm to develop away from the dryline, similar to what occurred yesterday, but the dryline remains the better focus for any more sustained convection late this afternoon and early evening. Any storm that develops should remain isolated, with steep lapse rates supporting some hail potential and collapsing cores capable of producing strong downburst winds. The cold front will move into North Texas Tuesday morning, reaching the I-20 corridor around midday and Central Texas by late afternoon or early evening. Showers and storms should increase in coverage along the front as it moves into a moist and unstable airmass, with the highest rain chances gradually shifting south and east through the day. Damaging winds and hail will be the primary severe hazards, with the overall intensity tied to how much instability can build ahead of the boundary and how much influence any prior outflow has on the frontal zone. Activity should gradually diminish from north to south Tuesday evening as the front settles into Central Texas, with cooler air filtering into North Texas behind the boundary. && .LONG TERM... (Tuesday night through next Sunday) Issued at 139 PM CDT Mon May 18 2026 The front will slow and become draped across Central or Southeast Texas Tuesday night into Wednesday while southwest flow persists aloft. Showers and storms will remain possible near and north of the boundary, but Wednesday currently looks like a relative minimum in rain chances for much of North and Central Texas as the better forcing and deeper moisture convergence focus farther east and southeast. PoPs will remain in the forecast area-wide, but the highest coverage should favor East Texas and Southeast Texas during this period. Temperatures will trend cooler behind the front, with clouds and scattered precipitation keeping many areas near or below seasonal normals through midweek. Rain and storm chances should increase again on Thursday as a compact shortwave embedded in the southwest flow pivots across Central Texas while the remnant frontal zone remains nearby. This setup should provide a better overlap of ascent, moisture, and boundary-focused lift, supporting another round of more widespread showers and thunderstorms. Severe weather potential appears limited by weaker shear and less favorable instability compared to Monday and Tuesday, but locally heavy rainfall will become a greater concern. This will be a cumulative rainfall event, and by Thursday the earlier rounds of rain may begin to moisten the top layer of soils enough to lower runoff thresholds, especially where storms repeatedly move over the same areas.Periodic rain and storm chances will continue Friday into the holiday weekend as additional weak disturbances move through the persistent southwest flow. The placement of the old frontal zone and any convective outflow boundaries will continue to drive the location of the heaviest rainfall from day to day, keeping confidence lower in the exact corridor of higher totals. The overall pattern supports beneficial rainfall for many areas, but localized flooding concerns may increase where repeated rounds occur, particularly across Central Texas, East Texas, and the Brazos Valley. Severe weather potential should remain low late week into the weekend, with locally heavy rain and occasional lightning becoming the main concerns. && .AVIATION... (18Z TAFS) Issued at 139 PM CDT Mon May 18 2026 Strong south winds will remain the primary aviation concern through the afternoon and early evening with sustained speeds around 20-25 kt and gusts to near 30-35 kt. VFR will prevail through the evening, with winds gradually decreasing after sunset. Another round of MVFR ceilings will arrive late tonight into early Tuesday morning, generally 06-09Z, with the lowest cigs likely across Central Texas including KACT. A cold front will move into North Texas on Tuesday with showers and thunderstorms expected to cross the Red River by mid morning and move through the region through the afternoon and evening. The most likely window for impacts at the Metroplex terminals will be 19-23Z, with gusty and erratic winds, brief visibility reductions, and MVFR/brief IFR conditions possible in heavier storms. Timing and placement details will continue to be refined in later TAF issuances, but a wind shift will likely accompany the front and any stronger storm outflows. && .SPOTTER INFORMATION STATEMENT... Issued at 1220 AM CDT Mon May 18 2026 Spotter activation is not expected at this time. && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 74 87 68 81 / 10 90 70 50 Waco 75 87 69 81 / 10 80 70 50 Paris 73 83 66 79 / 20 90 70 70 Denton 75 86 65 79 / 10 90 70 40 McKinney 74 86 66 80 / 10 90 70 50 Dallas 75 88 68 82 / 10 90 70 60 Terrell 73 87 68 81 / 10 80 70 70 Corsicana 76 89 71 83 / 20 80 70 70 Temple 76 89 70 82 / 10 70 70 60 Mineral Wells 73 87 64 79 / 10 90 70 40 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...12 LONG TERM....12 AVIATION...12  175 FXUS64 KSJT 181840 AFDSJT Area Forecast Discussion National Weather Service San Angelo TX 140 PM CDT Mon May 18 2026 ...New LONG TERM... .KEY MESSAGES... - Severe Storms possible Tuesday afternoon and evening. - Medium to High (30-80%) chances for showers and thunderstorms from Tuesday evening through Friday. && .SHORT TERM... (This evening through Tuesday) Issued at 1256 PM CDT Mon May 18 2026 The main concern in the short term this afternoon through tomorrow will be the potential for severe storms. For today, the main area of concern will be along our western CWA border, generally north of Sterling City. We have plenty of moisture in place with dewpoints in the 60s to around 70 degrees. As warming takes place today, SB CAPEs in excess of 4000 J/kg are possible this afternoon, as a dryline approaches from the west. There is shortwave energy embedded in southwest flow aloft that could aid in initiation of convection. Deep layer shear is not overly impressive, but with the amount of instability available, that would likely be overcome by any storms that can develop to produce severe weather with the primary concerns being large hail and severe wind gusts. The main problem with this afternoon is that most high resolution models maintain enough convective inhibition through this evening to prevent convection from developing. However, considering the amount of instability available, if storms do develop, they should quickly strengthen to severe levels, so will have at least a low (20%) chance for thunderstorms north of I-20 in the western Big Country. For Tuesday, a cold front will move into the area from the north shortly after sunrise tomorrow morning. As this front moves south during the morning hours, heating along and south of the front will allow for strong destabilization, with SB CAPE values again approaching 4000 J/kg. The front, along with an approaching shortwave, is expected to provide enough lift to produce thunderstorms by late morning or early afternoon in our area. Deep layer shear values of 20 to 40 knots, combined with the strong instability will any storms that develop to become severe, with the main hazards being large to very hail and damaging winds. And with the frontal boundary available, tornadoes cannot be completely ruled out. Highs south of the front will be able to warm into the lower 90s, while north of Interstate 20, highs in the low to mid 80s are expected. && .LONG TERM... (Tuesday night through next Monday) Issued at 140 PM CDT Mon May 18 2026 An active spring like pattern will continue through much of the long term with a persistent upper level southwest flow and a few disturbances moving across our area. Also, the combination of a cold front just south of the area and abundant moisture(PW values 1 to 1.75 inches) will bring a risk of localized flash flooding, especially Wednesday as the WPC has a slight risk of excessive rainfall across much of the area plus the Northwest Hill Country and southern Heartland Tuesday night. There are medium to high chances of rain for at least a few days in the long term. Also, there is an isolated to scattered severe weather threat(slight risk) for mainly the southern 2/3 of the area Tuesday evening as the cold front moves south and interacts with strong instability and some wind shear. Also, isolated severe storms are possible across the Concho Valley and Northern Edwards Plateau on Wednesday afternoon and evening. The main hazards will be large hail and damaging winds and a very low chance of an isolated tornado. Temperatures will be cooler with highs in the upper 70s and 80s, around to slightly below normal for this time of year. && .AVIATION... (18Z TAFS) Issued at 1256 PM CDT Mon May 18 2026 There are some lingering VIS values of 4SM to 6SM, but expect these values to improve to P6SM within the next hour or so. Ceilings have all improved to VFR, and these should remain VFR through late tonight, with another round of MVFR CIGs moving back into the area from the southeast after 06Z tonight. A cold front will move into the area tomorrow, but timing is still uncertain at this time, so have not shown a wind shift at KABI just yet. && .PRELIMINARY POINT TEMPS/POPS... Abilene 72 86 63 78 / 10 80 50 50 San Angelo 72 92 63 80 / 0 80 60 50 Junction 73 90 65 82 / 0 50 80 60 Brownwood 72 88 64 80 / 0 70 70 50 Sweetwater 71 87 62 77 / 10 60 40 50 Ozona 71 89 64 82 / 0 50 50 50 Brady 72 88 64 79 / 0 60 60 50 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...20 LONG TERM....21 AVIATION...20  290 FXUS63 KDDC 181842 AFDDDC Area Forecast Discussion National Weather Service Dodge City KS 142 PM CDT Mon May 18 2026 .KEY MESSAGES... - Strong to severe thunderstorm chances (50-70%) pick up across south central Kansas late afternoon through early evening. - Unseasonably cool temperatures arrive tonight and stick around through at least Wednesday. && .DISCUSSION... Issued at 134 PM CDT Mon May 18 2026 WV imagery indicates a closed upper low pushing east through eastern Utah into western Colorado. Near the surface, a quasi-stationary frontal boundary extends from the eastern Texas Panhandle northeastward through northwest Oklahoma into south central Kansas. Another round of thunderstorms (50-70% chance) are expected to develop across central/south central Kansas late today as the SREF indicates an embedded upper level shortwave within a larger scale trough quickly cycling northeast through the Colorado Rockies this afternoon, and farther up into the Upper Midwest this evening. In response, a quasi-stationary frontal boundary is forecast to move very little through early evening before being dislodged southward by a secondary frontal boundary surging in from the north. Ample moisture pooling south of the boundary with surface dewpoints well up into the mid/upper 60s(F) to near 70F will provide significant instability with MUCAPE values in excess of 4000 J/kg. Despite a less than robust southwest flow aloft (<50kt), thunderstorm development is likely late this afternoon as the core of the upper level shortwave passes just to our northwest in conjunction with a weakening cap as low/mid-level lapse rates steepen from peak daytime heating. The HREF supports this showing a 20-40% probability of 6-hr QPF exceeding 0.25 of an inch across south central Kansas, generally southeast of a Larned to Minneola line by late this evening. Strong instability and favorable deep layer shear will increase severe potential, including large hail and possibly a tornado or two. Drier conditions will then take hold through at least early Wednesday with drier air spreading southward into western Kansas while surface high pressure shifts eastward across the Dakotas into the Upper Midwest. Unseasonably cool temperatures are forecast tonight as much cooler air surges southward into western Kansas behind a cold front pushing through western Kansas into northern Oklahoma early/mid-evening, dropping the H85 5C isotherm well down into extreme southwest Kansas. With the HREF painting a 70-90% probability of temperatures dipping below 45F across the region in question to a 30-50% probability of temperatures falling below 50F in south central Kansas, expect lows generally down into the 40s(F) with the upper 30s(F) possible out near the Colorado line. Temperatures remain below normal Tuesday as surface high pressure in the Upper Midwest helps reinforce a the cooler air mass across western Kansas within an easterly upslope flow with H85 temperatures ranging from around 10C in central Kansas to near 15C in extreme southwest Kansas. Considering the HREF shows a 70-90% probability of temperatures topping 65F in west central/central Kansas to a better than 90% probability of exceeding 65F farther south near the Oklahoma line, look for afternoon highs mainly in the 60s(F). Similar temperatures are likely Wednesday under the influence of a prevailing easterly upslope flow. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1100 AM CDT Mon May 18 2026 IFR cigs are expected to linger in vicinity of KHYS through mid- afternoon as prevailing low level stratus continues to erode slowly northward, then return to VFR the remainder of the afternoon as the stratus scatters out. Otherwise, primarily VFR conditions will persist in vicinity of KLBL, KDDC, and KGCK through early Tuesday. Thunderstormdevelopment is likely along and ahead of a warm front projected to advance northward across south central Kansas late this afternoon through early evening. However, storms are expected to remain east of a KHYS to KDDC line. Light north-northeast winds will persist across west central and portions of southwest Kansas north of a quasi-stationary frontal boundary extending from the eastern Texas Panhandle northeast into south central Kansas. Meanwhile, southerly winds around 15 to 25kt with gusts up to 35kt will continue across south central Kansas into eastern portions of southwest Kansas south of the boundary through early evening. North winds around 15 to 25kt with gusts up to 30kt are forecast to develop generally after 23-01Z behind a cold front pushing southward through western Kansas this evening. && .DDC WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 9 PM CDT this evening for KSZ074>078- 084>088. && $$ DISCUSSION...JJohnson AVIATION...JJohnson  339 FXUS63 KGRB 181844 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 144 PM CDT Mon May 18 2026 Forecast discussion for routine afternoon forecast issuance .KEY MESSAGES... - Isolated severe storms possible through tonight. Greatest coverage of storms northwest part of the area late this evening and overnight. - Drier and cooler mid to late week. Frost or freeze headlines may be needed Tuesday night and Wednesday night. - Warmer by next weekend with return of rain chances. && .DISCUSSION... Issued at 142 PM CDT Mon May 18 2026 Main concern is chance of severe storms through tonight ahead of an approaching cold front. Modified warm front is working through the area from the south. It is running into affects from earlier storms to south and southeast. Subsidence to west of storms over Michigan is resulting in minimal re-development of showers and storms thus far. Decent cu field is blossoming over western WI into central WI, but capping is noted on forecast soundings in these areas rest of the day. Lowered pops to slight chance all areas through 5p. An warm and certainly more humid day by recent standards. Primary convective development this afternoon into early evening will be well to the south over the central Plains. As the warm front lifts north, it could be enough to overcome the capping for a few storms to develop, especially northern WI. Isolated strong storm is possible with MUCAPE up to 1000J/kg and effective shear of 30-40 kts. Severe threat will be higher if a storm could become truly surfaced based and occur near the front. Wave to north of this convection over the plains along with approaching sfc low looks to bring best chance of a line of storms late this evening into the overnight hours for central and north-central WI. Main hazard with these storms will be gusty winds and heavy rain. Isolated damaging wind gust could occur if line remains more organized as it moves into the area. Overall the chance for severe weather this afternoon through tonight has trended downward as SPC has trimmed the Slight Risk out of all our forecast area. Leftovers of this overnight line of storms shift by late tonight. A few showers or storms may linger through the morning over eastern WI, just ahead of cold front. The front sweeps through by early afternoon, shifting southwest winds to northwest. Winds will be gusty up to 30 mph. Highs could touch 70 over eastern WI, but will be in the 60s for most, with even some 50s over north-central WI. Beyond Tuesday, rest of the week looks generally dry. Canadian high shifts across late Tuesday through Wednesday night. Frost or freeze headlines may be needed Tuesday night and Wednesday night, especially northern WI. Greatest risk is Wednesday night with high overhead and PWATs less than 0.5 inch. Min RH will be low Wed through Fri afternoon's. Return flow kicks in late this week into next weekend with highs steadily returning to at or above normal. Chances for rain and perhaps some thunder increase by next weekend. && .AVIATION...for 18Z TAF Issuance Issued at 1256 PM CDT Mon May 18 2026 Low pressure and a modified warm front lift across WI through tonight. Cold front sweeps through on Tuesday morning. Subsidence in wake of cluster of storms over Lake Michigan and lower Michigan will restrict pop-up showers and storms this afternoon. As the warm front lifts through, could be isolated showers and storms late this afternoon into this evening. Another line of showers and storms will move into central and north-central WI late this evening and overnight. Not clear whether this line makes it into eastern WI. A few lingering showers and storms on Tuesday morning, then it dries out with gusty northwest winds developing behind the cold front. Cigs MVFR to VFR today, lowering to IFR to MVFR late tonight into early Tuesday. Cigs improve to VFR in all areas on Tuesday afternoon. Southerly winds gust to 15-20 kt into this evening, with winds shifting southwest into the overnight. Winds shift to northwest Tuesday morning, with gusts to 25 kt. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....JLA AVIATION.......JLA  645 FXUS63 KIND 181847 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 247 PM EDT Mon May 18 2026 .KEY MESSAGES... - Severe storms possible this afternoon and again Tuesday afternoon and evening with damaging winds the primary threat - Heavy rain and some flooding are possible into the evening and again Tuesday - Highs in the 80s Tuesday - Storms will end Wednesday as the front shifts south, but unsettled weather likely returns late this week into the holiday weekend && .DISCUSSION (This evening through Monday)... Issued at 246 PM EDT Mon May 18 2026 Rest of This Afternoon and Tonight... Please see the latest Mesoscale Discussion section for details on the current convective situation. Thunderstorms will continue to move east this afternoon, with faster movement across the northern forecast area. To the south, the cold pool is having a harder time moving south, and showers and storms continue to develop as the low level jet impinges upon it. Later this afternoon into early evening, some additional upper energy will produce additional showers and thunderstorms. Will continue high PoPs this afternoon into early evening, especially southwest where the regeneration of storms will continue along the cold pool boundary. This regeneration of showers and storms in the southwest may lead to flooding, so will continue the Flood Watch. May have to adjust the location of the watch if the area of regeneration shifts. The main threat for severe will be out ahead of the initial line of storms into the afternoon. Damaging winds will be the primary threat. Coverage of rain will diminish this evening into the overnight as most forcing exits. However, some weak upper energy may keep the threat for a few showers around northwest. Went cooler than guidance for lows given the rain cooled air. Tuesday... Uncertainty remains on how convection will develop on Tuesday with the surface cold front moving in. There may be cloud cover in the morning from upstream convection which would help limit instability. Some CAMs limit coverage to the southeast forecast area, while larger scale models bring rain to all areas Tuesday into Tuesday night. Given the strength of the front and the plentiful moisture, went likely PoPs all areas at some point Tuesday afternoon and evening. The severe threat will depend on how well the instability is able to build. Damaging winds will be the primary severe threat. Given today's rainfall and the plentiful moisture Tuesday, heavy rain and flooding will remain a threat for Tuesday as well. Highs on Tuesday could reach the middle and upper 80s if morning clouds are thin enough and rain holds off long enough. Wednesday and Thursday... Some rain may linger Wednesday morning in the south, so kept some low PoPs there. There remains some uncertainty on how far south the front will then settle and thus how fast it returns north. GFS seems aggressive with returning rain on Thursday, so will keep most of the area dry through the daytime Thursday. Rain chances begin to spread north Thursday night. Much cooler air will return for this period with highs in the upper 60s to around 70 and lows in the middle 40s to lower 50s. Friday through Memorial Day... A northern stream upper trough will move into the central USA while a southern stream smaller upper wave moves into the area. These will help bring the surface front northward back into the area into Saturday. Decent moisture will move back north with it, so will have likely or higher PoPs Friday into Friday night. Upper energy may interact with the lingering front to produce some rain on Saturday, so will keep PoPs around. A couple of upper troughs will bring more rain chances Sunday into Memorial Day. There remains some decent uncertainty on timing and strength, so will broadbrush PoPs and keep them under the likely category until uncertainty improves. With the surface front having lifted north, warmer air will return, with perhaps 80s again by the latter half of the holiday weekend. However, confidence isn't high in these given the uncertainty in rain coverage Sunday into Memorial Day. && .MESOSCALE UPDATE... Issued at 1244 PM EDT Mon May 18 2026 Thunderstorms are developing along the Indiana Illinois state line. These storms have been loosely organized so far, but an outflow boundary from convection further upstream is impinging from the west. This outflow boundary may allow storms to consolidate into a more coherent line as they progress deeper into Indiana. A recent sounding from Purdue University shows modest lapse rates between 6-7 C/Km, with a moist profile to about 500 mb. Additionally, modest shear is also present (20-25 knots) with messy hodographs centered around the mean storm motion. As such, little in the way of storm relative upper-level outflow appears likely...storms should behave more like single cells to multicell clusters until they become influenced by the outflow boundary or their own outflow. Once storms consolidate on the outflow boundary, they should still be relatively 'pulsey' in nature but more organized than in the open warm sector. The primary threat today appears to be strong wind gusts, as enough moisture loading within mature updrafts is possible for wet microbursts. Additionally, cold pool dynamics such as rear- inflow jet surges are also possible which may produce strong to damaging wind gusts. Given a mean shear vector towards the northeast, cold pools that orient in a NW to SE direction pose the greatest threat for severe wind gusts. Hail is possible but given only modest lapse rates, high moisture content, and the lack of long straight hodographs it does not appear to be all that likely. Tornado potential also appears low, given the outflow dominant nature of storms today. A brief QLCS spin up cannot be ruled out, however. Another threat, likely replacing wind as the primary hazard later this evening, is the potential for flooding and flash flooding. High- resolution guidance shows the cold pool settling in a SW to NE fashion across central Indiana. This may allow for repeated rounds of storms into tonight. As mentioned above, moisture content in the profile is high and freezing levels are near 15,000 feet. With a warm cloud layer over 10,000 feet in thickness, warm rain processes should lead to efficient rainfall production today. As such, various CAMs are showing pockets of very heavy rainfall totals between 3 to 5 inches. HREF ensemble mean shows a large area of 1 to 2 inches. Because of this potential, a Flood Watch has been issued for for western portions of the area. As cold pools become more defined, this may need to be trimmed or expanded. && .AVIATION (18Z TAF Issuance)... Issued at 114 PM EDT Mon May 18 2026 Impacts: - Showers and storms at times into this evening - Peak wind gusts this afternoon at 25 to 30kts Discussion: Initial area of convection impacting the western sites at the moment will continue to move east and will impact the other sites early in the period. Additional development will continue into the evening, so there will be periods of showers and storms through about 03Z. IFR and worse are possible in convection. While additional convection may pop up overnight, better chances for convection return closer to 18Z Tuesday. Gusty winds will continue this afternoon, and near LLWS conditions are possible tonight. && .IND WATCHES/WARNINGS/ADVISORIES... Flood Watch until 11 PM EDT this evening for INZ043>045-051>054- 060>062-067. && $$ AVIATION...50 DISCUSSION...50 MESOSCALE...Eckhoff  712 FXUS61 KLWX 181849 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC Issued by National Weather Service Mount Holly NJ 249 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... Minor adjustments to the thunderstorm chances this afternoon and evening based on current radar trends, otherwise no major changes were made to the forecast package. && .KEY MESSAGES... 1) Near record warmth with isolated strong to severe thunderstorms over the mountains today and Tuesday. 2) A strong cold front brings widespread rain and thunderstorm chances on Wednesday, followed by much cooler and showery conditions toward the end of the week. && .DISCUSSION... KEY MESSAGE 1... Near record warmth with isolated strong to severe thunderstorms over the mountains today and Tuesday. It's a very hot start to the workweek as upper level ridging strengthens over the region. Aside from areas under the influence of the bay breeze and higher terrain locations, widespread 90s have been reported across the region as of 3 PM. There are a few hours left today for some additional heating, so no major changes with the forecasted highs. This will mark one of the hottest days so far this season, although even hotter conditions can be expected Tuesday as the upper level ridge peaks over the region. Scattered showers and storms have already started to develop over the higher terrain. Storm coverage is expected to be limited in nature given the lack of a direct lifting mechanism. Hi-res CAMS show good continuity in regards to convective development that will be fueled by ample instability, steep low level lapse rates, and marginal shear. MLCAPE values of 1000-2000 J/kg, DCAPE values of 1000-1300 J/kg, and enough mid- level flow (20-30 kt) will provide some organization to any cold pools that develop. This supports forecast soundings with inverted V profiles indicative of damaging winds which aligns with several hi - res model members suggesting gusts of 40-50 kts on any storms that form. Any thunderstorm activity will quickly diminish through the evening hours with dry conditions and areas of patchy fog. Don't expect too much relief from the heat tonight with lows in the upper 60s and low 70s. Even hotter conditions can be expected Tuesday with highs well into the low to mid 90s. A few upper 90s cannot be ruled out across the urban corridor and down to the south across the central VA Piedmont given the strengthened ridge peaking overhead and dry air at the surface. An isolated shower or t-storm remains possible over the mountains, although most will see nothing given the heightened ridge squashing anything overhead. Temperatures cool slightly Wednesday with increasing cloud cover as a cold front approaches the region. Highs will still push into the 90s along with increasing humidity. Even with that said, the combination of heat and humidity will remain below heat headline criteria through the period. KEY MESSAGE 2...A strong cold front brings widespread rain and thunderstorm chances on Wednesday, followed by much cooler and showery conditions toward the end of the week. A strong area of low pressure moves through the Northeast on Wednesday, with a cold front extending down the East Coast that will bring widespread rain and thunderstorm chances to the Mid-Atlantic in the afternoon/evening. While the center low will be well north of us, the timing of the front aligning with the diurnal cycle and the high temperatures seen at the start of the week could still contribute towards some thunderstorm development in the region. Potential severity at this time still ranges widely--NCAR's AI NWP Convective Hazards Forecast currently has our region outlined in its 45%-60% probability for severe weather to occur, while CSU's medium- range probabilities ranks the severe threat much lower. Regardless, this front will likely result in widespread showers at a minimum as well as a sharp drop in temperatures seen later in the week. Highs on Thursday will range in the upper 60s and low 70s, a marked shift from the mid-90s expected earlier in the week. Lingering rain showers may still be moving out of the area by Thursday morning, while a meandering front to the south could bring a few additional rain showers on Friday. Temperatures begin to increase again going into the weekend, as a warm front meanders through the region Saturday. Upper-level zonal flow slow transitions to UL ridging by the end of the weekend, indicating a potential decrease in rain chances going into the start of next week. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions are expected to prevail across the terminals through Wednesday morning as high pressure strengthens offshore. South/southwesterly winds return today and Tuesday gusting between 15 to 20 kts during the afternoon and evening hours. Daily shower and thunderstorm chances will occur each afternoon although coverage will be spotty in nature mainly at terminals along and west of a line from KMRB, KHGR, KFDK, to KEKN. Elsewhere confidence remains low given the lack of a lifting mechanism and strengthening high pressure overhead. Sub-VFR restrictions return at times Wednesday afternoon and evening as a cold front brings widespread showers and thunderstorms to the region. Winds will remain out of the southwest ahead of the front before shifting back to the north and northwest Thursday. Some low CIGS may hang on through Wednesday night before lifting Thursday as the front sits south of the region. Periodic rain showers moving through the region on Thursday and Friday could bring additional sub- VFR periods at terminals towards the end of the week. Wind gusts could reach 15-20 knots on Thursday before gradually decreasing. Northerly winds shift east-southeast by Friday night. && .MARINE... SCA southerly channeling over the bay and lower tidal Potomac is expected this afternoon and evening. Winds will drop briefly back below sub-SCA levels tonight before additional SCAs are needed due to channeling Tuesday afternoon and evening. Winds will remain out of the south and southwest with gusts up to 20 kts today and Tuesday. Winds may near low-end SCA levels in south to southwesterly flow on Wednesday, and then again in northerly flow on Thursday. SMWs appear possible Wednesday into Wednesday night as thunderstorms move over the waters. Small Craft Advisories are likely during the day Thursday & Friday as winds gust up to 15-20 knots, growing calmer overnight. Winds drop below SCA thresholds Friday night. Northerly winds shift easterly by Friday morning. && .CLIMATE... Here are some daily temperature records during the May 18-20, 2026 timeframe: A '+' sign indicates multiple years currently hold that record. A '!' sign indicates the record is forecast to be tied or broken. ***MONDAY, MAY 18TH, 2026*** LOCATION RECORD HIGH (YEAR) RECORD WARM LOW (YEAR) Washington-National (DCA) 96F (1877) 72F (2015) Washington-Dulles (IAD) 91F (1987)! 68F (2015)! Baltimore (BWI) 97F (1962) 70F (2017) Baltimore Inner Harbor (DMH) 97F (1962) 75F (2017) Martinsburg (MRB) 96F (1911) 66F (2015)! Charlottesville (CHO) 95F (1962)+ 73F (1911) Annapolis (NAK) 95F (1962)+ 69F (1953)+! Hagerstown (HGR) 93F (1962) 71F (2017) ***TUESDAY, MAY 19TH, 2026*** LOCATION RECORD HIGH (YEAR) RECORD WARM LOW (YEAR) Washington-National (DCA) 96F (1997)+ 72F (2015)! Washington-Dulles (IAD) 92F (1997)+! 66F (2017)+! Baltimore (BWI) 98F (1962) 75F (1877) Baltimore Inner Harbor (DMH) 98F (1962) 78F (1962) Martinsburg (MRB) 98F (1911) 69F (1996)! Charlottesville (CHO) 97F (1962) 72F (1997) Annapolis (NAK) 96F (1962) 71F (1911)! Hagerstown (HGR) 97F (1996) 69F (2017)+! ***WEDNESDAY, MAY 20TH, 2026*** LOCATION RECORD HIGH (YEAR) RECORD WARM LOW (YEAR) Washington-National (DCA) 96F (1996) 73F (2019) Washington-Dulles (IAD) 93F (1996) 69F (2019) Baltimore (BWI) 95F (1962) 71F (2019)+ Baltimore Inner Harbor (DMH) 97F (1962) 74F (1998)+ Martinsburg (MRB) 97F (1911) 70F (1998) Charlottesville (CHO) 96F (1996) 73F (1996) Annapolis (NAK) 98F (1997) 76F (1898) Hagerstown (HGR) 97F (1996) 66F (1998) && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory until 2 AM EDT Tuesday for ANZ531>534- 537>543. && $$ DISCUSSION...BRO/KJP/EST/SRT/99 AVIATION...BRO/EST/SRT/99 MARINE...EST/SRT/99  679 FXUS62 KMLB 181848 AFDMLB Area Forecast Discussion National Weather Service Melbourne FL 248 PM EDT Mon May 18 2026 ...New KEY MESSAGES, DISCUSSION, MARINE, FIRE WEATHER... .KEY MESSAGES... Issued at 245 PM EDT Mon May 18 2026 - Isolated/scattered showers and storms through the week, especially south of Cape Canaveral. A slight increase in rain chances is forecast this weekend, areawide. - A Moderate HeatRisk gradually expands across east central Florida, especially late week into the weekend; adequate hydration and breaks from the heat will be important for those spending time outdoors. - High risk for life-threatening rip currents continues at ALL central Florida Atlantic beaches. Entering the dangerous surf is strongly discouraged! && .DISCUSSION... Issued at 245 PM EDT Mon May 18 2026 Now-Tonight...Showers and scattered storms from this morning have continued into the early part of the afternoon along the Treasure Coast. This is where 1.6-1.7"+ PW exist, according to GOES-derived PW imagery. Farther north, mostly dry conditions continue with temperatures in the mid/upper 80s. CAMs are suggesting a gradual end to coastal rain/storms, transitioning activity toward the west FL coast late this afternoon and evening. However, model initialization has lagged behind what is being observed on radar, so trends will be monitored for coastal activity to linger a bit longer. East- southeast winds remain gusty, reaching 25 mph at times. Across the interior, wind speeds are forecast to decrease after sunset to 5-10 mph. Along the coast from the Cape southward, persistent easterly flow looks to keep winds elevated (10-15 mph) through the night. As a result, mid 70s are forecast along the Volusia/north Brevard coast while lows in the upper 70s are expected. Isolated coastal showers and occasional lightning strikes cannot be ruled out overnight, though chances are low (15-20%). Tuesday-Sunday...Not a whole lot of change is expected to our overall setup from mid week into the Memorial Day weekend. Surface high pressure remains anchored well offshore over the Atlantic with an H5 ridge well north of Florida. There is a broad mid level low that rotates toward the ECFL coast Wednesday, helping to moisten 300- 500mb layer a bit more. It remains to be seen whether that will at all support any more shower/storm coverage, particularly at the coast. By the end of the week, this feature becomes rather disorganized while moving away from ECFL, toward the Bahamas. With continued ESE flow, rain chances that start the day at the coast will again end across the interior and west coast of FL. Precip chances increase modestly Friday into the weekend as moisture increases areawide. This update carries a 40-55% chance for showers and storms each afternoon, which is a slight downward trend from this morning's forecast (but closer to climo). H5 temps will be warming as well, so the primary concern with any stronger storm would be gusty winds. High temperatures warm into the low 90s for much of the area after Thursday, with the coast remaining in the upper 80s behind the daily sea breeze. Gusts around 20-25 mph along and in the wake of the sea breeze are likely to continue as well. With additional moisture comes a higher heat index, forecast to reach the upper 90s to low 100s Friday-Sunday. Warm and muggy conditions each night will provide little relief around the clock, so at least a Moderate HeatRisk is forecast. For those considering beach plans this holiday weekend, a moderate to high risk of rip currents will continue as onshore winds persist. Always heed the advice of lifeguards! When red flags are flying, entering the water is strongly discouraged. && .MARINE... Issued at 245 PM EDT Mon May 18 2026 East-southeast flow, gusty at times, remains through the week as high pressure remains anchored well offshore. Embedded in the onshore flow at times are isolated to scattered showers and storms, some of which contain frequent lightning and gusty winds around 30 kt. Outside of storms, seas may briefly build to 5 ft overnight but generally remain 2-4 ft through late week. Small craft should exercise caution, offshore south of the Cape and in the nearshore Treasure Coast waters tonight. && .AVIATION... (18Z TAFs) Issued at 118 PM EDT Mon May 18 2026 Continued SHRA/TS on the Treasure Coast this afternoon, but activity should gradually diminish. Otherwise, deep ESE flow up to 15 kt continues with VFR prevailing. Few additional showers around DAB/TIX are favored in the guidance late tonight. Low confidence if this makes it into MCO tomorrow morning/midday, will need to monitor trends. && .FIRE WEATHER... Issued at 245 PM EDT Mon May 18 2026 High pressure centered well offshore will help maintain east- southeasterly winds through the week and into the weekend. Sustained winds during the day of 10-20 mph with gusts around 25 mph are possible, along with briefly higher gusts embedded in showers or isolated lightning storms. The greatest chance for rain and storms will be south of the Cape, transitioning inland with the afternoon east coast sea breeze. However, many locations will remain dry. Recent dryness will prolong fire sensitive conditions, and any lightning strikes could lead to new fire starts. && .PRELIMINARY POINT TEMPS/POPS... DAB 75 86 74 87 / 20 20 10 20 MCO 73 89 73 89 / 10 30 10 30 MLB 77 85 77 86 / 20 20 10 20 VRB 77 87 77 87 / 20 20 10 20 LEE 72 90 72 90 / 0 30 10 30 SFB 73 89 72 90 / 10 20 10 30 ORL 73 89 73 89 / 10 30 10 30 FPR 76 86 76 86 / 20 20 20 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ DISCUSSION...Schaper AVIATION...Heil  765 FXUS61 KCTP 181850 AFDCTP Area Forecast Discussion National Weather Service State College PA 250 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... * Day 2 SPC Outlook upgraded to a Slight Risk (Level 2 out of 5) for damaging winds in northwest PA. && .KEY MESSAGES... 1) Hottest temperatures of the year so far forecast this afternoon along with some scattered storms in south central PA. 2) More heat & humidity will produce scattered showers and thunderstorms on Tuesday afternoon and evening, some of which could be strong to severe, especially across northern PA. 2) A strong cold front to bring showers and thunderstorms with the potential for severe weather on Wednesday followed by colder temperatures. && .DISCUSSION... KEY MESSAGE 1: Hottest temperatures of the year so far forecast this afternoon along with some scattered storms in south central PA. An expansive deck of fair weather cumulus had developed across the Commonwealth this afternoon with very warm temperature and sticky-but-not-overly-humid dewpoints. Convection has begun to fire in the West Virginia panhandle and will continue to extend north-northeastward this afternoon and evening as temperatures continue to rise under an anomalous upper level ridge. 500 mb heights per the GEFS will rise to near 590mb this afternoon across southeast PA, correlating to standardized anomalies of +2 sigma along the Mid Atlantic Coast through 18z Tuesday. We collaborated with LWX and SPC to paint a MRGL risk for SVR TSRA this afternoon from the Scent Mtns to the West Branch Valley of the Susq. This corridor will be near the eastern edge of somewhat stronger (35-40 kt) swrly mid level winds with MU CAPE reaching near 2000 J/KG. Additionally, the eastern edge of an elevated mixed layer (currently over the Middle Ohio River Valley) will be tracking ENE at 15-20 kts and reach the western edge of the MRGL Risk area around 22-23Z today helping to enhance mid level lapse rates and updraft intensity. The primary hazard with these pulse storms will be the potential for gusty winds associated with the the clearly high- based convection occurring within an inverted-V sounding. Daily record highs could be challenged in some locations. See the Climate section for more details. Manual adjustments were made to lower NBM maxT by a few degrees today due to a known systematic bias correction issue identified during the shoulder seasons. This should also keep max heat indices under 100F, precluding any need for Heat Advisories. Still, heat risk impacts will continue to be monitored given the quick ramp-up in heat and limited acclimation time. Dewpoints over 60F for many will also feel more humid relative the recent cool stretch we've had. ------------------------------------------------------------- KEY MESSAGE 2: More heat & humidity will produce scattered showers and thunderstorms on Tuesday afternoon and evening, some of which could be strong to severe, especially across northern PA. By Tuesday, we'll still be under the influence of the anomalously strong ridge of high pressure, with broad southwesterly flow continuing to pump warmer temperatures and humid conditions into Pennsylvania. Highs on Tuesday should be fairly comparable to today, though afternoon showers/storms in the west could limit how warm it gets there. At the surface, a deepening surface low will lift across the Great Lakes with gradually sinking heights aloft impinging northwest PA. Underneath this sprawling ridge, Pennsylvania will be in a moist and unstable airmass with MUCAPE values expected to reach 1000-1500J/kg. With marginal but sufficient shear, this amount of instability could support a few stronger storms will strong to damaging wind gusts. The SPC upgraded NW PA to a Slight Risk (Level 2 out of 5) of severe weather Tuesday afternoon. The Marginal Risk extends down to about halfway between I-80 and I-76. Low level hodographs do exhibit some spin and an isolated tornado cannot be ruled out in northwest PA closer to the parent surface low pressure system. CAMs disagree on the extent to which convection initiation will occur Tuesday afternoon, but the heat and humidity will provide as much fuel for storm development as we've seen yet this year. Rainfall amounts are not expected to be all that impressive with this system, largely owing to unimpressive/relatively dry moisture profiles with dewpoints in the upper 50s to low 60s. The good news is that these lower dewpoints will keep our heat index values below 100F and mitigate the need for Heat Advisories across the area. Rainfall amounts will be highest west of I-99 and locations farther east may not see much rain at all before Wednesday. -------------------------------------------------------------- KEY MESSAGE 3: A strong cold front to bring showers and thunderstorms with the potential for severe weather on Wednesday followed by colder temperatures. A cold front (accompanied by more widespread and frequent showers/t-storms) brings relief to the relatively short bout of heat and moderate humidity Wednesday into Thursday. High temperatures on Wednesday in northwest PA (behind the front) will be nearly 20 degrees cooler than Monday/Tuesday. The Lower Susquehanna Valley will squeak out another warm day with highs in the upper to 80s to near 90F. Ahead of and along the front, there will be a risk for severe weather again on Wednesday. The magnitude & location of the severe threat will be highly dependent on cold front passage timing and amount of cloud cover in advance of the frontal boundary. A Marginal Risk area covers locations south and east of the I-80/I-99 corridor and highlights locations along and downstream of the cold front between 12PM and 8PM on Wednesday. A few of the hi-res models depict a slower cold front passage. Such a solution would allow for more destabilization ahead of the front and a higher threat for damaging straight line winds. If the front ends up being faster than progged, clouds/rain in the morning could limit instability and lead to an unimpressive gusty shower event. Regardless, this system will feature beneficial rainfall with rainfall amounts generally 0.10-0.25" and locally higher totals possible in thunderstorms. In the wake of the cold front, high pressure will build in for a short time. Temperatures are forecast to cool down back to historical/climo averages for late May for the end of next week. Early indications show the aforementioned cold front stalling out south of the Mason-Dixon line late in the week and lifting back north across PA as a warm front into Memorial Day weekend. The current outlook favors a cooler/wetter stretch through the holiday weekend thanks to that warm front, but there is still a lot of time for the forecast to trend in a more favorable and optimistic direction for the holiday weekend that marks the unofficial start of summer. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Scattered cumulus clouds have been noted moving over the central Pennsylvania air space. Flight conditions are expected to remain VFR throughout the TAF period outside of a an isolated thundershower this afternoon. Confidence is overall low on thunderstorm development this afternoon. Forcing for storms is weak despite the available energy in the atmosphere. Latest CAM guidance would indicate a narrow window for convective storms to develop after 22Z this afternoon. These storms will be very isolated in nature, and PROB30 groups have been included at airfields that may see one of these storms. Overnight, a shortwave tracking across the Great Lakes may result in a few showers/thundershowers across West-Central PA (mainly KBFD), though flight restrictions appear unlikely with this activity. After 12Z on Tuesday clouds will begin to scatter out again and clear, with wind gusts up to 25kts possible again on Tuesday throughout the afternoon. Outlook... Tue...Mainly VFR. Patchy A.M. fog possible. Isolated P.M. shower or t-storm possible. Wed...Restrictions probable through Wednesday night with widespread showers/storms along CFROPA. Thu...Lingering showers across S PA, restrictions possible. Fri...Lingering showers across S PA, restrictions possible. && .CLIMATE... Daily record max temperature for May 18-19: 5/18 5/19 Harrisburg 94 in 1962 95 in 1962 Williamsport 95 in 1962 96 in 1996 Altoona 91 in 1962/1996/2017 92 in 1996 Bradford 85 in 1962 85 in 1962 State College 92 in 1962 92 in 1934/1996 Overnight low temperatures on Monday night into Tuesday are also in jeopardy. Please note: State College Co-operative observations are a 24-hour summary taken once per day around 7 AM (7AM-7AM). Therefore, a max temp occurring in the daylight or late in the day is usually reported in the _next_ day's observation. Also, the same min temp may be reported on two consecutive days if the min occurs at observation time. && .CTP WATCHES/WARNINGS/ADVISORIES... Air Quality Alert until midnight EDT tonight for PAZ057-059- 063-065-066. && $$ WHAT HAS CHANGED...Banghoff KEY MESSAGES...Banghoff/Ciampi DISCUSSION...Banghoff/Ciampi AVIATION...Bowen/Teare CLIMATE...Dangelo/Steinbugl  807 FXUS64 KBMX 181851 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 151 PM CDT Mon May 18 2026 ...New DISCUSSION... .KEY MESSAGES... Issued at 150 PM CDT MON MAY 18 2026 - Warm conditions are expected today and tomorrow with highs near 90 degrees. - Chances for showers and storms will be above average Wednesday through the weekend, with the highest (40-70%) chances in northern and western portions of Central Alabama during the afternoon and evening hours. && .DISCUSSION... (This afternoon through Sunday) Issued at 150 PM CDT MON MAY 18 2026 Temperatures are warming up nicely across the area with many areas approaching 90 degrees. A mid-level trough is located over the western CONUS, while mid-level ridging is generally in place over the Gulf, Southeast CONUS, and western Atlantic, though there is a broad upper low near the Bahamas. At the surface, low pressure is located over Kansas with a Bermuda high over the western Atlantic. Overall we are in a summer-like pattern, indicating the beginning of the summer convective season. Showers are already developing in southern Alabama, in an area of 1.5 inch GOES-derived PWAT values lifting northward. Latest HREF guidance indicates isolated to scattered showers and storms lifting northward late this afternoon and into the early evening, aided by this enhancement in moisture and weak confluence on the west side of the Bermuda high. However, ridging aloft and a lack of higher PWAT values will be a limiting factor for coverage. MLCAPE values will be around 1000-1500 J/kg this afternoon with weak mid-level lapse rates and weak shear. This should limit overall updraft intensity, with severe storms being unlikely, but with DCAPE over 1000 J/kg there will be a risk for gusty winds with any stronger storms. Heights increase slightly on Tuesday while some lower PWATs advect in from the east. The daytime hours look to be mainly dry and warm across Central Alabama. Convection will develop ahead of the stalling cold front over Mississippi aided by some weak vorticity maxima in southwest flow aloft. Some of the activity and its outflow boundaries may move into our northwest counties Tuesday night. CAMs generally indicate this activity more or less falling apart, but low to medium (20-40%) rain chances will continue through the overnight hours Tuesday night. Wednesday through the end of the week a quasi-stationary frontal boundary will remain stalled to our northwest, with elevated PWATs in the 1.7-1.9 inches lingering through the extended period, highest far northwest. Positively tilted troughing will be located to our north and west, with ridging being suppressed to the Gulf. This will place Central Alabama under southwest flow aloft with several shortwaves moving through and continued low- level southerly flow off of the Gulf. Chances for showers and storms will remain above climatology for much of the rest of the period in the 40-70% range, lower than that in the southeast counties. We are not expecting a washout, but occasional periods of showers and storms, with details dependent on outflow boundaries and MCVs from previous days. 0-6 km bulk shear values around 20-25kts may be sufficient for multicells at times, with convection being of the "pulse" variety. While widespread severe weather is not expected, some isolated to widely scattered instances may occur. Overall rainfall amounts should mostly be beneficial, though if some areas get several rounds of heavy rainfall then some minor flooding could occur. 32/JDavis && .AVIATION... (18Z TAFS) Issued at 1231 PM CDT MON MAY 18 2026 VFR conditions are expected the next 24 hours outside of any convection. Sufficient moisture and weak confluence on the west side of the Bermuda high will result in isolated to scattered SHRA/TSRA initially in the vicinity of MGM, then potentially northward to BHM/EET. However, coverage will be limited by ridging aloft. PROB30s are included at MGM/EET/BHM, while at AUO/TCL probabilities are only 20 percent and will not be mentioned. Variable gusty winds may occur with any TSRA. 32/JDavis && .FIRE WEATHER... Isolated to scattered showers and storms are forecast this afternoon, with mainly dry conditions expected Tuesday afternoon. Min RH values will be in the 40-50% range both afternoons. Rain chances increase by mid week and continue into the weekend as a front stalls near the region, with higher Min RH values. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 65 88 65 87 / 10 10 10 70 Anniston 65 88 66 86 / 10 0 10 60 Birmingham 70 89 70 87 / 30 0 10 70 Tuscaloosa 69 90 69 88 / 20 0 20 50 Calera 67 90 67 88 / 30 0 10 60 Auburn 67 89 68 88 / 10 0 0 30 Montgomery 68 90 69 89 / 20 0 10 40 Troy 66 90 68 89 / 20 0 10 40 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...32/JDavis AVIATION...32/JDavis  889 FXUS64 KAMA 181853 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 153 PM CDT Mon May 18 2026 ...New KEY MESSAGES, SHORT TERM, LONG TERM, AVIATION... .KEY MESSAGES... Issued at 143 PM CDT Mon May 18 2026 - High-end critical to extremely critical fire weather conditions persist Today. - A cold front will arrive this evening bringing northerly winds and cooler temperatures. - Showers and thunderstorms are possible beginning as early as Tuesday night and extending through Saturday. && .SHORT TERM... (This evening through Tuesday night) Issued at 143 PM CDT Mon May 18 2026 Hot, dry, and gusty conditions are solidly imposing their will on the Panhandles once again today, creating high-end critical to extremely critical fire weather conditions across the Panhandles. These details are investigated further in the fire weather forecast discussion. A storm system traversing the central Plains today is responsible for our active weather today, and will continue pushing eastward through the overnight hours. As the base of this large trough passes over the region through this afternoon, a sharpening dry line will become rooted in the vicinity of the TX - OK state line. East of this feature, southeast winds are advecting higher dew points in the 60s while building strong instability of over 4000 J/kg MLCAPE. This environment would be extremely conducive for severe thunderstorms capable of all hazards (damaging, hail, & tornadoes), but it is uncertain if we will get any successful attempts at convective initiation in the far eastern Panhandles before the dry line fully mixes out of our CWA into western Oklahoma. Proximity to better synoptic support would give the far NE & SE Panhandles near Beaver/Lipscomb and Collingsworth counties respectively the better chances for storms, although the probability for development is still only about 15%. As the system departs, a relatively strong cold front will drop southward over the region this evening, bringing breezy northerly winds of 15-25 mph with gusts up to 35 mph through the overnight hours (10-20% chance for a few rogue gusts >40 mph). This will finally provide improved moisture and cooler temperatures to mitigate fire weather concerns for the Panhandles by Tuesday. Winds will gradually settle to 10-15 mph later tomorrow with cooler highs in the 70s and lows in the 40s for most locations. Harrel && .LONG TERM... (Wednesday through next Sunday) Issued at 143 PM CDT Mon May 18 2026 Is a pattern change truly on the way? Will rain chances finally pan out? Medium and long range weather models have been insisting for some time now that the onset of El Nino will provide increasing moisture opportunities for the high Plains during late May to early June. Now that we are knocking on the door of this time frame, models have insistingly held onto this hope for better rain chances over the next week or two. Ensemble projections depict multiple rounds of systems approaching the Panhandles beginning Wednesday and lasting into next week, with decent potential to pull improved moisture along with them. Many of these opportunities will likely only bring hit or miss showers and storms, but some locations could certainly get lucky with rain any given day during this stretch (15-30% POPs daily). Wednesday - Thursday is currently the most promising window for storms, as southwest flow aloft settles atop the Plains and draws improved theta-e thanks to troughing over the western CONUS. Concerns exist that a localized dry slot may prevent moisture return from effectively spreading across the area Wednesday, but many models have additional moisture influx negating this issue later in the day. Highest confidence in storm development exists further west in thehigher terrain of New Mexico and further south across the West TX Big Country, but some of this activity could spread north and east into the Panhandles if moisture is favorable. Thursday's rain chances would likely be conditional based on Wed night activity, but the synoptic pattern will remain relatively unchanged. One bonus to the forecast pattern outside of rain chances, is the high likelihood of the return to near or below average temperatures to end the month. After the anomalously hot, windy, and dry stretch we've been in, the outlook of lighter winds, cooler temperatures, and higher humidity should provide an extremely welcomed reprieve from fire weather concerns. Harrel && .AVIATION... (18Z TAFS) Issued at 143 PM CDT Mon May 18 2026 Gusty southwest winds of 20-30 kts with gusts around 40 kts will persist through this afternoon-evening at all sites. These winds will likely kick up blowing dust, but are not expected to provide significant visibility reductions. A cold front will shift winds out of the north this evening through the end of the period, initially at 15-25 kts with gusts up to 35 kts. Winds will settle down tomorrow morning through the end of the period. Mentions of LLWS may need to be included for tonight behind the front if confidence increases as we get closer. Otherwise, VFR ceilings are forecast at all sites. Harrel && .FIRE WEATHER... Issued at 1053 AM CDT Mon May 18 2026 With extremely critical fire weather conditions still expected to materialize this afternoon and evening, the arguably greatest factor of concern lies with any existing fires and the arrival of a cold front to the region later this evening. This front dropped further south than models anticipated this morning, helping higher humidity and cooler temperatures linger across the NW and central Panhandles. Unfortunately, there are no favorable parameters for these conditions to linger through the day, and the front should easily retreat northward allowing drier air and southwest winds of 25-35 mph gusting up to 50 mph to take over the rest of this afternoon-evening. The cold front will fully breach the Panhandles this evening, quickly shifting winds out of the north at 15-25 mph gusting up to 35 mph (10-20% chance for a few gusts >40 mph). Better moisture behind the front will help humidity values greatly improve overnight (60-90% RH), but the initial wind shift will pose a significant risk for any existing fires to spread rapidly southward. This front is currently projected to reach the OK Panhandle as early as 6-8 PM, the northern and central TX Panhandle as early as 8-10 PM, and the I- 40 corridor by 10 PM to midnight. We will monitor the timing of the front closely through the day. Harrel && .AMA WATCHES/WARNINGS/ADVISORIES... TX...Red Flag Warning until midnight CDT tonight for TXZ001>020-317. Wind Advisory until 8 PM CDT this evening for TXZ001>020-317. OK...Red Flag Warning until midnight CDT tonight for OKZ001>003. Wind Advisory until 8 PM CDT this evening for OKZ001>003. && $$ SHORT TERM...38 LONG TERM....38 AVIATION...38  894 FXUS65 KBYZ 181853 AFDBYZ Area Forecast Discussion National Weather Service Billings MT 1253 PM MDT Mon May 18 2026 .KEY MESSAGES... - Frost/freeze Tuesday morning with temperatures in the mid to high 20s F. Make sure to protect sensitive vegetation. - Another weather system brings the chance (40-90%) of precipitation Wednesday into Thursday. Snow levels around 6,500 ft. - 50% chance for getting greater than 0.75 inches of precipitation for the Beartooth foothills. Possible impacts to the East Side burn scar. && .DISCUSSION... Today through Monday... A widespread freeze is expected Tuesday morning with temperatures in the mid to high 20s F for most locations. Act now to protect sensitive plants. Temperatures increase into the 60s Tuesday afternoon. Wednesday will see a 500 mb wave impact the region. Models continue to indicate this wave diving further south with increasing precipitation values. A cold front will move through the region late Wednesday bringing 40-90% precipitation chances late Wednesday through Thursday with chances decreasing from west to east. Weak low pressure over Northeast Wyoming/Western Dakotas is expected to turn 700 mb winds northeasterly bringing good upslope for foothills locations. Ensembles show that the farther the trough digs south and the farther west the trough sets up, the more precipitation the region can expect to receive. The NBM is giving locations west of Rosebud County a 40-90% chance of getting greater than 0.25 inches of precipitation with the highest chances in the mountains and foothills. Locations from Rosebud County and east have a 20-40% chance for greater than 0.25 inches. Precipitation type will be snow in the mountains and rain for the lower elevations with snow levels around 6,500 ft. Given the favorable setup for the Beartooth foothills there is a 50% chance for getting greater than 0.75 inches of precipitation. This could cause concern for the East Side burn scar. Storms are not expected and the precipitation is expected to be long duration acting to limit any burn scar risks. Snow levels will also be important, if snow levels set up lower there will be no risk to the burn scar. Temperatures are expected to be in 70s F Wednesday before cooling into the 60s F Thursday and Friday. Saturday and Sunday will see temperatures increase into the 70s and 80s F with dry conditions. Torgerson .AVIATION... Isolated rain and snow showers will continue to decrease this afternoon and evening. MVFR to local IFR conditions are possible with the showers. Expect occasional mountain obscuration due to mountain snow through the evening. As skies clear and winds decrease overnight, some patchy fog is possible (20% chance) for central and eastern valleys, including near KSHR and KMLS. Archer && .PRELIMINARY POINT TEMP/POPS... Tdy Tue Wed Thu Fri Sat Sun ------------------------------------------------------- BIL 050 030/067 042/071 043/061 040/068 043/079 049/085 1/E 00/U 11/B 87/T 21/B 00/U 01/U LVM 048 026/062 036/065 036/057 034/066 038/075 045/081 4/W 10/B 13/T 98/T 21/B 10/U 11/U HDN 050 026/067 036/073 041/061 037/069 040/078 046/085 1/E 00/U 00/B 57/T 31/B 10/U 01/U MLS 048 030/064 040/073 044/065 040/069 042/077 047/083 1/E 00/U 00/B 44/W 21/B 10/U 01/U 4BQ 045 029/062 039/072 042/064 040/066 042/076 047/083 3/W 00/U 00/U 16/T 42/W 10/U 01/U BHK 046 028/060 036/073 039/066 037/066 040/075 046/083 4/W 20/U 00/B 25/T 32/W 20/U 01/U SHR 043 024/060 031/067 036/055 033/064 035/074 040/082 9/W 00/U 01/B 39/T 43/W 11/U 01/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings  945 FXUS61 KBOX 181854 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 254 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... Heat Advisories issued for most of Southern New England Tuesday and Wednesday with the first multi-day stretch of hot temperatures and a moderate degree of humidity. Record high temperatures remain possible. && .KEY MESSAGES... - First multi-day stretch of hot temperatures (in the mid to upper 90s away from the South Coast) with a moderate degree of humidity Tuesday and Wednesday. Near record heat possible. - Isolated thunderstorms possible Tuesday north and west of Interstate 95. Better chances for strong to severe thunderstorms on Wednesday with strong straight line winds the main risk. - Seasonable and dry Thursday and Friday. - Cooler and unsettled weather is possible Memorial Day Weekend, but confidence remains low. && .DISCUSSION... KEY MESSAGE 1...First multi-day stretch of hot temperatures (in the mid to upper 90s away from the South Coast) with a moderate degree of humidity Tuesday and Wednesday. Near record heat possible. A spell of anomalous heat (e.g. 850 mb temps running in the upper teens Celsius, which are 2-3 standard deviations above climatological normals for late May) will build into Southern New England on Tue, only slightly cooler on Wed. SW breezes should also mitigate the risk for cooling seabreezes but will keep the immediate South Coast, Cape and Islands considerably cooler than further inland (highs mid 70s/low 80s). Away from the South Coast, highs on Tuesday should reach the mid 90s in most areas with upper 90s possible due to westerly downsloping in the CT and Merrimack Valleys. With a southward-sagging frontal boundary nearby on Wed, highs project to be a few degrees cooler in the upper 80s/low 90s north of the Mass Pike and low-mid 90s in the CT-RI-SE MA corridor, with still cooler temps 70s/near 80 South Coast/Cape and Islands. Even though the NAM-based guidance shows dewpoints in the mid 60s to low 70s, it usually demonstrates a moist-bias in these strong-mixing days and values should be closer to the mid 50s to mid 60s Tue and Wed. That's also a factor which will be alluded to in the next Key Message to follow. We're looking at a spell of hot temperatures but a generally drier heat, not necessarily oppressively humid like we typically see with forecasted temperatures this hot. With dewpoints mid 50s to lower 60s, it's more of "drier" heat and the difference between the air temperature and the apparent temperature (heat index) may not be that much different. Framing this setup a little more, if this type of setting were deeper in the summer months, it might not rise to the level of heat headlines. However WPC and CDC's HeatRisk graphics outline portions of the CT and Merrimack Valleys in the Major HeatRisk classification. Given this datapoint, forecasted heat indices which are borderline (mid to upper 90s), and that there may be individuals who are not yet accustomed to this degree of heat as of yet, we opted to issue a Heat Advisory for Tuesday and Wednesday. KEY MESSAGE 2...Isolated thunderstorms possible Tuesday north and west of Interstate 95. Better chances for strong to severe thunderstorms on Wednesday with strong straight line winds the main risk. The warm airmass Tuesday and Wednesday will create a maginally to moderately-unstable convective setting, with some risk for thunderstorms both days. I'm skeptical of the NAM's inflated instability parameters given the above moist-bias (upper 60s to low 70s) and the highest CAPE values stem from the NAM and its downscaled 3-km version, but even the drier GFS shows about 1000 J/kg on Tuesday and again on Wednesday. Soundings show a well-mixed PBL favorable for downdraftand gust-front production if any showers or storms can pop up. What may trigger storms on Tuesday is debatable, as the best mid- level winds/stronger wind shear and strong cold front is to our north and west. A passing sfc trough could be enough to generate isolated storms north and west of I-95; one or two could become strong if storms develop with strong winds the main risk; the lack of sufficiently strong wind shear would lead to more pulse- type storms. Wednesday may offer a better chance at strong to severe storms with the approaching cold front interacting with moderate instability. The front's timing is in some question but somewhat better chances for thunderstorms near to south of the Mass Pike. Both days feature a Level 1 of 5 (Marginal Risk) for severe weather. KEY MESSAGE 3...Seasonable and dry Thursday and Friday. Thursday and Friday are fairly straightforward, with a 1030mb high pressure system across the Great Lakes on Thursday before shifting east on Friday, leading to dry weather. What is most noticeable is the cooler air mass. 850mb temperatures lower to +2C to +5C on Thursday, a far cry from the +18C to +20C observed just a few days prior. With a dry and well-mixed boundary layer, mixing up to 850mb seems likely, tapping into those cooler temperatures aloft and yielding highs in the middle 60s to around 70F both days. Considering climatological normal maximum temperatures for mid-May are generally in the upper 60s to lower 70s, this is more typical for the time of year versus the early taste of summer that challenged daily record highs. With clear skies Thursday night and nearly calm winds as surface high pressure moves overhead, good radiational cooling is expected, allowing temperatures to lower into the 40s, with perhaps some upper 30s across the higher elevations of northern and western Massachusetts. While slightly cooler than normal, temperatures will be nowhere near record-setting. KEY MESSAGE 4...Cooler and unsettled weather is possible Memorial Day Weekend, but confidence remains low. The unofficial start to summer this weekend brings the potential for unsettled weather, though there remains a good deal of uncertainty due to model variability at this range. However, it bears watching given the numerous outdoor activities planned for Memorial Day Weekend. Global deterministic and ensemble guidance show the potential for rainfall, particularly Saturday night into Sunday, though there remain large differences in timing among models and runs. That said, it is worth noting both the AIGFS and ECMWF AIFS depict a 1035mb surface high pressure system situated east of New England, suppressing precipitation to the west. This solution would favor a drier, albeit cooler, weekend with easterly flow and highs generally in the lower 60s. For now, the NBM PoPs remain the best first estimate for the upcoming weekend, but do not write it off just yet, there is still pounds of time for forecast adjustments. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 18Z TAF Update: Mainly VFR conditions through Wed. However, stratus and fog will likely develop over the ocean as SW flow brings higher dewpoints over cooler ocean and this may impact portions of the south coast and Cape/Islands tonight. LLWS risk for all terminals tonight heading into early Tue morning. Isolated t-storms possible Tue afternoon, but uncertain on if they will impact any terminals. E-NE wind becoming S 10-20 kt this afternoon. S-SW wind 5-10 kt tonight increasing Tue with gusts to 25 kt developing. KBOS...High confidence in TAF. Seabreeze today with wind shift to S late today or early evening. KBDL...High confidence in TAF. Outlook /Tuesday Night through Saturday/... Wednesday: VFR. Breezy. Chance SHRA, slight chance TSRA. Wednesday Night: VFR. Breezy. Thursday through Friday: VFR. Friday Night: VFR. Chance SHRA. Saturday: Mainly VFR, with local IFR possible. SHRA likely. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Through Tuesday Night: High confidence. Issued small craft advisories valid from 12z Tuesday through Wednesday evening. SW winds will be increasing to around 15-25 kt Tuesday and remain so through Wednesday, higher over the southern waters. Seas will also be building to around 4-6 ft, with some 7 footers possible Tuesday night over the southern waters. Mainly dry weather prevails through Tuesday night, although fog may develop both tonight and Tuesday night. Outlook /Tuesday Night through Saturday/... Wednesday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Chance of rain showers, isolated thunderstorms. Wednesday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers. Thursday: Winds less than 25 kt. Seas locally approaching 5 ft. Thursday Night through Friday: Winds less than 25 kt. Friday Night: Winds less than 25 kt. Chance of rain showers. Saturday: Winds less than 25 kt. Rain showers likely. && .CLIMATE... Record Highs for Tue May 19... BOS 90/1949 BDL 94/1962 PVD 91/2017 ORH 92/1962 Record Highs for Wed May 20... BOS 91/1996 BDL 99/1996 PVD 95/1996 ORH 91/1903 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...Air Quality Alert until 11 PM EDT this evening for CTZ002. Heat Advisory from 11 AM Tuesday to 8 PM EDT Wednesday for CTZ002>004. MA...Air Quality Alert until 11 PM EDT this evening for MAZ008>011. Heat Advisory from 11 AM Tuesday to 8 PM EDT Wednesday for MAZ003>007-010>019-026. RI...Heat Advisory from 11 AM Tuesday to 8 PM EDT Wednesday for RIZ001>004. Air Quality Alert from 11 AM to 11 PM EDT Tuesday for RIZ001>008. MARINE...None. && $$ DISCUSSION...Loconto/Dooley AVIATION...Dooley/McMinn MARINE...Loconto/Dooley CLIMATE...KJC  915 FXUS65 KGGW 181854 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 1254 PM MDT Mon May 18 2026 .KEY MESSAGES... - Tuesday morning will be cold across northeast Montana, with chances for near record lows if clouds clear out overnight. - Warm weather returns mid week. The next chance for showers returns Wednesday. && .DISCUSSION... WEATHER PATTERN OVERVIEW: A strong upper trough will keep cool conditions through tonight before weakening and allowing temperatures climb closer to normal by Wednesday. Tonight low temperatures look to drop below freezing with clearing skies and light wind. With these cooler temperatures, make sure to protect sensitive vegetation. By mid week upper level ridging over the west coast will allow quick moving shortwave troughs to sneak through the overall quasi- zonal flow, bringing some isolated thunderstorm chances through the end of the week. The best chance for thunderstorms will be Wednesday. Model plumes continue to suggest weak instability in the ~300 J/kg MLCAPE range during Wednesday evening. GEFS forecast RH and dewpoint for Wednesday evening continue to rise. FORECAST CONFIDENCE & DEVIATIONS: No changes to NBM. && .AVIATION... LAST UPDATED: 1900Z FLIGHT CAT RANGE: MVFR-IFR through daytime. MVFR-VFR by Tuesday. DISCUSSION: Overcast conditions with isolated rain showers will persist over the region through the afternoon and evening. Clouds begin to clear out sometime overnight from west to east, and any clouds that do remain should be right around the MVFR threshold. Temperatures could be below freezing for many locations Tuesday morning. WINDS: Winds will be north to northwest through this evening at 10-15kts. By close to midnight, expect a transition to light and variable winds which should remain through midday Tuesday. Cliff && .GGW WATCHES/WARNINGS/ADVISORIES... None. && $$ weather.gov/glasgow  038 FXUS61 KBTV 181856 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 256 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... As of 252 PM EDT Monday... No significant changes have been made at this time. Well above normal temperatures are expected Tuesday with the potential for strong to severe thunderstorms. && .KEY MESSAGES... As of 252 PM EDT Monday... 1. Well above normal temperatures expected on Tuesday with much cooler weather expected on Wednesday and Thursday. 2. Strong to locally severe thunderstorms possible Tuesday afternoon and evening. 3. Cooler and drier conditions are favored Thursday and Friday before a transition back to seasonable temperatures and a wetter pattern. && .DISCUSSION... As of 252 PM EDT Monday... KEY MESSAGE 1: Continued warm air advection will set the stage for unseasonably warm temperatures on Tuesday. The latest NBM shows high potential for 90 degree weather, however, much of the other guidance and MOS is showing temperatures likely plateauing in the mid to upper 80s. Cloud cover and convection will be a huge factor in determining how warm we get as a lot of guidance suggests partly to mostly cloudy skies. Any convection would increase cloud cover and any precipitation would drop temperatures significantly. Still, there is overwhelmingly high confidence in high temperatures being 15 to 20 degrees above normal. On Wednesday, a cold front will likely push through the region during the morning hours which will limit daytime heading with strong cold advection expected to follow in the wake of the front. We could still warm into the 80s across eastern Vermont but will likely be in the 70s for most of Vermont and New York based on the timing of the frontal passage. Thursday will be 10-20 degrees colder than Wednesday as we will see temperatures struggle to climb into the mid 50s to lower 60s. North winds in the 10-20 mph range will help make it feel a bit blustery, especially after the recent warmth. Most clear skies should help it feel a little warmer given the late May sun angle. KEY MESSAGE 2: The convective potential for Tuesday continues to remain very conditional. A lot of the machine learning and AI tools are showing modest probabilities (15-30%) for severe weather Tuesday afternoon and evening while the latest deterministic guidance shows rather lackluster instability. There is high confidence in around 50 knots of deep-layer shear as we have a strong 500 jet move overhead but the thermodynamic profiles keep fluctuating from model run to model run. Even though temperatures are expected to warm into the mid to upper 80s and dewpoints rising in the lower to mid 60s, the mid-level lapse rates between 850 mb and 500 mb aren't exactly what you want to see to maximize severe potential. In addition, no notable surface convergence outside of orographic lifting is expected with the cold front not expected to come through until Wednesday morning. There will be some weak height falls under anticyclonic flow aloft and a weak shortwave trough pushing through which will give up some deep layer support but getting storms to initially develop will be difficult. The main focus, initially, will be across the higher terrain and along lake breezes as this could create some surface convergence and the upper level support could take over from there. There may be residual cloud cover from overnight convection across western New York which may stunt surface heating. Should this occur, instability values may underperform further and lead to little to no thunderstorm activity. Hence the condition potential. Largely unidirectional wind profiles with slight curvature in the Champlain Valley is expected which likely makes Tuesday a wind threat. High LCLs will strongly inhibit tornado potential with high freezing levels also making severe potential very difficult to come by. The main window for convection will be between 4 and 8 PM with instability waning rapidly following sunset. KEY MESSAGE 3: Winds weaken Thursday night with skies clearing; this may be a period of concern for some frost outside the Champlain Valley with lows in the mid/upper 30s for many locations, and low 40s for the Champlain Valley. Temperatures begin to warm up on Friday with northwest flow weakening, high temperatures will reach the 60s areawide. A slow warming trend is then expected through the weekend into Monday. Models begin to split on precipitation timing heading into the weekend. Consensus maintains some chances of showers increasing Saturday with more widespread rain Sunday. However, a number of models are beginning to hold onto the ridge longer delaying precipitation onset until the late weekend. Either way, a pattern shift to deep return flow from the Gulf Coast northeastward into the Northeast is appearing probable. This flow pattern would result in multiple days of rain potential once it sets up. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Through 18Z Tuesday...A low level jet will sweep through this afternoon promoting some LLWS for MSS/SLK/PBG/EFK. Surface winds at PBG could gust 20-30kts at times with favorable off- lake, channeled flow while most other terminals see gusts around 20kts. Gusts drop by 00Z with clouds thickening early morning as a diffluent flow pattern moves over the region with some increasing elevated instability. A few showers will be possible after 06Z, but widespread LLWS will return as the next lljet moves into the region 00-12Z. Winds slacken overnight but pick up again Tuesday morning. Outlook... Tuesday Night: VFR. Slight chance SHRA, Slight chance TSRA. Wednesday: Mainly VFR, with local MVFR possible. Chance SHRA. Wednesday Night: VFR. NO SIG WX. Thursday: VFR. NO SIG WX. Thursday Night: VFR. NO SIG WX. Friday: VFR. NO SIG WX. Friday Night: VFR. Chance SHRA. Saturday: VFR. Chance SHRA. && .MARINE... As of 300 AM EDT Monday... A Lake Wind Advisory is in effect for the Broad Waters of Lake Champlain. Winds have been slow to materialize thus far after plenty of cloud cover and rainfall this morning stunted the winds on Lake Champlain. Winds have currently increased to 15 knots in the broad lake and will continue to increase to 25 knots between 8 and 10 PM this evening. These stronger winds will continue through 8 AM on Tuesday and will diminish to 15 knots or less on Tuesday. Waves are currently ranging between 1 and 2 feet and are expected to increase to 2-4 feet this evening with the highest waves expected across the broad lake. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ WHAT HAS CHANGED...Clay DISCUSSION...Clay/Neiles AVIATION...Neiles MARINE...Clay  057 FXUS63 KGLD 181856 AFDGLD Area Forecast Discussion National Weather Service Goodland KS 1256 PM MDT Mon May 18 2026 .KEY MESSAGES... - Scattered light rain showers through early evening. - Frost possible Tuesday morning west of Highway 25 as temperatures fall into the low to mid 30s. - Occasional shower chances through the rest of the week, perhaps a few isolated thunderstorms Thursday and Friday. && .SHORT TERM /THROUGH THURSDAY NIGHT/... Issued at 1245 PM MDT Mon May 18 2026 Low clouds, drizzle and light rain showers covering much of the area this morning will slowly erode on the southern edge through this afternoon, with the latest HRRR showing clearing as far north as Interstate 70 by 22z. Afterwards, the clouds will push south again and they will persist through much if not the entire night. Deepening low pressure in southwest Kansas will result in northwesterly winds gusting to 30-40 mph generally south of Interstate 70 between 00-06z, then gradually decreasing overnight. Chance for any light showers will end with the wind shift. Due to the persistent clouds and wind, temperatures will likely only drop into the low to mid 30s for lows, so issued a Frost Advisory to account for that. Clouds will finally dissipate Tuesday morning leaving a mostly sunny and milder day with highs mainly in the 60s. Next shortwave trough will come out of Colorado Tuesday night, and combined with surface winds turning to east and southeast will result in scattered light rain showers. Overnight precipitation amounts will be less than a tenth of an inch. The showers will continue to increase in coverage Wednesday morning as additional shortwave energy moves out of Colorado in the persistent southwest flow aloft. Weak instability in the afternoon is limited to the immediate vicinity of the Front Range and not expecting any thunder here. QPF remains light through the day on Wednesday, but there is a modest increase Wednesday night, with SREF/NBM means showing generally up to a quarter of an inch, but some deterministic output suggesting locally up to a half inch or more. High temperatures will be in the 50s and 60s with the clouds and precipitation, coolest in Colorado. Thursday will see a stronger disturbance move out of the northern Rockies into western Colorado by the afternoon, then moving across the area Thursday night. Shower and thunderstorm chances will increase once again. Instability will be limited by cloud cover, and models showing only weak SBCAPE of around 500 j/kg in the afternoon, mainly in Colorado. Deep layer shear will increase to 30-50 kts by 00z and may compensate somewhat for the weak instability in Colorado, where a marginally severe storm may be possible through the early evening before loss of heating. Scattered showers and isolated thunderstorms will continue through Thursday night as the upper wave makes its way across the area. Additional rainfall amounts Thursday night are generally between 0.25" - 0.50", though locally higher amounts over 1" are possible. Temperatures on Thursday could remain in the 50s, especially north of Interstate 70, where clouds persist through the day, with perhaps 60s further south or west with limited clearing. && .LONG TERM /FRIDAY THROUGH SUNDAY/... Issued at 217 PM MDT Sun May 17 2026 Wednesday, our region is forecast under a southwest upper-level flow with a weak trough developing west of the Rocky Mountains and a ridge building off the west coast. Wednesday will be cool and windy with high temperatures forecast in the 60s and wind gusts from 30 to 40 mph are possible west of Highway 27. Several embedded shortwaves will pass through the region bring chances for showers and thunderstorms Wednesday afternoon through Thursday morning. The entire county warning area (CWA) has a Probability of Precipitation (PoPs) around 30-40% during the day Wednesday. PoPs increase in the evening to around 60-70% and persist overnight into Thursday for the southern CWA. Conditions remain unseasonably cool for Thursday with highs again forecast in the 60s. Our region remains in a southwest upper-level flow with embedded shortwaves passing through, so chances for showers and thunderstorms continue. Cooler temperatures and a mostly stable environment will likely keep and storms that develop sub- severe. Pops range from 30-60% Thursday overnight into Friday with the southern CWA on the higher end. Ensembles are in disagreement on when the aforementioned trough ejects eastward and takes us out of the persistent southwest flow, but it will likely move on after Friday. A slight warming trend begins Friday with high temperatures forecast in the 70s for Friday and 80s for Sunday. Chances for showers and thunderstorms remain Friday through Saturday with PoPs around 20-30% for the eastern CWA as several shortwaves pass through the area. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1112 AM MDT Mon May 18 2026 IFR will continue through most of the TAF period at both KGLD and KMCK due to low ceilings and occasional showers/drizzle. Surface winds will shift to northerly late this afternoon with gusts up to 35 kts through early evening, then gradually diminishing the rest of the night. Not expecting a return to VFR until Tuesday morning when ceilings will lift. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...Frost Advisory from midnight MDT /1 AM CDT/ tonight to 8 AM MDT /9 AM CDT/ Tuesday for KSZ001-002-013-014-027-028-041- 042. CO...Frost Advisory from midnight tonight to 8 AM MDT Tuesday for COZ090>092. NE...Frost Advisory from midnight MDT /1 AM CDT/ tonight to 8 AM MDT /9 AM CDT/ Tuesday for NEZ079-080. && $$ SHORT TERM...024 LONG TERM...Rhoades AVIATION...024