583 FXUS66 KOTX 181200 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 500 AM PDT Mon May 18 2026 .KEY MESSAGES... - Pop up showers and isolated thunderstorms primarily over the higher terrain will return Monday afternoon. - Cold overnight temperatures will bring a threat of morning frost Monday. This could impact sensitive plants or crops. - Conditions trend drier and warmer through the workweek regionwide, with periodic breezy winds for the Cascades and central WA. && .SYNOPSIS... Diurnally forced showers with isolated afternoon thunderstorms will continue today Monday. Precipitation chances decrease and afternoon highs trend warmer through the workweek, climbing back into the 70s and 80s by Thursday and continuing through next weekend. Breezy winds are expected at times through the Cascade gaps and across the western Columbia Basin. && .DISCUSSION... Today through Friday night: A deep longwave trough of lower pressure will remain over the CONUS for this weekend through the workweek. The axis of this longwave trough will slowly migrate over the Rockies by through Wednesday and then over the Plains by Thursday into Friday. The Inland Northwest will remain under the backside of this trough today with a conditionally unstable air mass. Lingering showers over extreme eastern Washington into the Idaho Panhandle early this morning will wane with decreasing instability at mid levels. However, diurnal heating will destabilize the lower levels of the atmosphere for the afternoon. There will be a lack of instability over the Columbia Basin today, which should result in much of the showers and thunderstorm activity confined to mainly the higher terrain today. Instability parameters will be much less compared to Sunday with upper levels trending warmer. Much less likely to see as much small hail like we've seen with this storms, but some is expected with slightly stronger thunderstorms over the mountains. Convection will also be capable of wind gusts up to around 20-25 mph and infrequent cloud to ground lightning strikes. Best potential for thunderstorms today will be over northeast Washington into the Northern Panhandle with 20-25% chance of occurring. Convection is expected to wane more quickly into the evening hours compared to Sunday. We then see a drying trend into mid week as a ridge of higher pressure in the eastern Pacific nudes east into the Northwest. There is a shortwave disturbance that pushes across BC on Tuesday and does bring a 20-30 percent chance for showers across the far northern mountains closer to the Canadian border, and this potential could linger into Wednesday for North Idaho as the shortwave pushes across fairly slowly. There is a 15% chance that places like Lauier, Northport, Metalline Falls, Porthill, and Eastport may also see a passing thunderstorm. Temperatures warm up above normal by Wednesday with our highs back into the 70s. The risk for morning frost will decrease as well as temperatures see a slow warm into the weekend. Saturday through Sunday: Model ensembles remain in pretty good agreement with a shortwave trough of lower pressure to flatten the ridge. There is uncertainty with how deep this shortwave will be. About 80 percent of the ensemble members show this disturbance to be fairly weak with minimal cooling of just a few degrees Saturday into Sunday. Westerly winds will see an increase. Stronger wind gusts of up to around 30 mph will be across the Cascades and into the western basin and up to around 20-25 mph potentially into places like Spokane and the Palouse. Winds would pick up Saturday afternoon, but could also remain fairly breezy into Sunday as well. Models continue to diverge as we head into the beginning of next week. Outliers such as the 00Z operational ECMWF and Canadianindicate a deep trough to dig in into BC and potentially as far south as the Pacific Northwest. This scenario would represent more cooling and a better potential for showers than what is in the forecast. The NBM suggests a more zonal flow pattern with the potential for progressive weaker waves that could bring light shower activity but nothing looking all that substantial. After our warm up late in the week, temperatures look to cool near normal for Sunday into the beginning of next week. /SVH && .AVIATION... 12Z TAFs: A moist boundary layer is in place early this morning across far eastern Washington and north Idaho. Nighttime microphysics satellite imagery reveals a stratus deck between 4.5k-7kft from Sandpoint to Pullman and patchy shallow fog from Deer Park to the Spokane metro area. Given the stratus deck across north Idaho, confidence is lower for fog development at KCOE. Fog at KGEG/KSFF may bring IFR/MVFR conditions through 16-17Z. Convective showers with isolated thunderstorms are expected 18Z-04Z primarily over the mountains of northeast Washington into the Idaho Panhandle. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Confidence is low for visibility restrictions and IFR conditions with radiational fog at KGEG/KSFF this morning. Low confidence for stratus to bring MVFR conditions to KCOE and KPUW. ----------------------- Confidence descriptors: Low - Less than a 30 percent chance Moderate - 30 to 70 percent chance High - Greater than a 70 percent chance For additional probabilistic information for NWS Spokane airports, please refer to the Aviation Dashboard on our webpage: https:/www.weather.gov/otx/avndashboard && .Preliminary Point Temps/PoPs... Spokane 66 41 69 44 72 45 / 10 10 0 0 0 0 Coeur d'Alene 64 41 67 44 70 45 / 20 20 10 0 0 0 Pullman 62 39 65 42 68 43 / 10 0 0 0 0 0 Lewiston 67 43 71 46 73 48 / 10 0 0 0 0 0 Colville 69 36 71 40 75 41 / 20 30 10 10 0 0 Sandpoint 62 40 66 43 68 43 / 30 30 10 10 0 0 Kellogg 61 39 66 43 68 43 / 20 20 10 0 10 10 Moses Lake 73 42 75 46 78 49 / 0 0 0 0 0 0 Wenatchee 72 48 74 51 77 54 / 10 0 0 0 0 0 Omak 73 43 75 48 78 51 / 10 10 10 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...Frost Advisory until 7 AM PDT this morning for Northeast Mountains-Okanogan Highlands-Spokane Area-Washington Palouse. ID...Frost Advisory until 7 AM PDT this morning for Central Panhandle Mountains-Coeur d'Alene Area-Idaho Palouse- Northern Panhandle. && $$  726 FXUS63 KLBF 181203 AFDLBF Area Forecast Discussion National Weather Service North Platte NE 703 AM CDT Mon May 18 2026 .KEY MESSAGES... - A cool, raw day is in store for western Nebraska Monday as daytime highs remain 20-30F below normal and light rain crosses the area. - Cooler overnight lows Monday and Tuesday night may lead to the potential for at least patchy frost/freeze conditions west of Highway 83. - Periodic light precipitation potential will persist through the upcoming week as daytime highs climb to seasonable and then above normal values by the late weekend. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 206 AM CDT Mon May 18 2026 Early this morning, scattered showers were lifting north and east across the Sandhills and portions of the Nebraska Panhandle. This was associated with a weak impulse located around h7 ejecting ahead of the parent trough situated across the Great Basin. Light rain is possible beneath this activity as low level humidity remains fairly high within a post frontal airmass. Temperatures largely sit in the upper 40s to lower 50s with breezy north winds. Cloud cover should keep temperatures from falling too significantly though morning lows will still reach 5-10F below normal for late May. Monday/Monday Night...northerly low-level flow will persist through the daytime across western Nebraska. The frontal inversion will support cloudy to mostly cloudy conditions for the bulk of the daytime and combined with persistent cold air advection, should keep temperatures in check across the region. Afternoon highs will likely only reach the lower 40s in the northwest to near 50F in our far south and east. These values will approach 30F below normal for mid- May and when factoring in steady north winds gusting 20 to 30 mph, feels like temperatures will struggle to climb out of the lower 30s for portions of the area. Main upper trough will begin to pivot by midday as it crosses the central Rockies to the west. This will lead to a fairly expansive area of thunderstorms along a stalled frontal boundary and associated baroclinic zone draped in southeast Nebraska. It is here where the Storm Prediction Center has maintained a Moderate Risk (Level 4 of 5) extending south into Kansas and folks with interests in these locations should check for local information regarding this threat from reliable sources. Further west in the local area, the cooler temperatures will all be prevent the threat for severe weather. While MUCAPE may approach 500 j/kg, perhaps enough for a rumble of thunder across central Nebraska, severe weather is not anticipated west or north of the Tri- Cities. Lift via increasing height falls, cyclonic vorticity advection, and frontal forcing should lead to expanding precipitation primarily for the Panhandle into portions of north central Nebraska. PoPs should gradually increase this afternoon with the highest probabilities arriving by early evening. Even with the cooler temperatures, precipitation is expected to fall as rain with colder air waiting to filter in until precipitation has departed. Rates should be slow and steady given primarily synoptic lift and limited if any instability. The result is showery activity overtop the widespread stratus. HREF probability matched mean (PMM) output suggests most locations see < 0.10" outside the Panhandle and our far northern counties. The going forecast matches this well with most locations seeing < 0.05" save for the Pine Ridge vicinity where closer to 0.20" seems plausible. Precipitation exits the area shortly after Midnight tonight with temperatures then falling to the upper 20s in the west to middle 30s east. The going forecast lows of 32F and 33F at North Platte and Valentine respectively fall into the lowest 10% of observed values for the May 19 date. Will defer to later forecasts for potential Frost/Freeze headlines but believe these will be necessary given recent updates of susceptible vegetation. Tuesday/Tuesday Night...behind departing trough, mid-level heights will begin to build quickly across the region. Surface high pressure will nose in from the west and support steady northwesterly winds. Increasing h85 temperatures and downsloping flow should produce a warmer day as temperatures look to return to the upper 50s to lower 60s. Subsidence aloft will allow for eroding clouds and dry conditions. High pressure will settle to the east and return southerly flow should become established by late evening. Cloud cover should increase as a result with subtle moisture advection over the High Plains. Forecast lows remain on par with Monday night's forecast values so additional Frost headlines may need to be considered if the current forecast holds. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Issued at 206 AM CDT Mon May 18 2026 The extended pattern will generally favor warming temperatures with periodic rain and thunderstorm potential. Southwesterly flow should return by mid week as modest troughing forms west of the Continental Divide. Moisture should increase across the area and set the stage for low-end PoPs periodically. Temperatures should moderate steadily with NBM median MaxT and MinT values showing 4-6F day-over-day climbs. Given the expected daytime temperatures returning to seasonable and then abnormally warm values, believe any precipitation potential will likely come in the form of thunderstorms. Generally weak mid-level flow will likely limit the threat for any widespread severe weather event at this time. An approaching trough on Friday may pose the greatest potential for western Nebraska as a cool front moves out of the Northern Plains. NBM matches this timeframe with 10-20% potential for seeing > 0.25" precipitation but greater probabilities are apparent east of the local area. Beyond Friday, drier conditions appear likely as precipitable water values fall off and upper-level ridging builds across the Western CONUS. NBM probabilities for exceeding 90F climbs by late weekend, with probabilities reaching 20-40% by Sunday and 40- 70% by Monday. Higher percentile outputs suggest mid to upper 90s for these days, but inner-quartile spreads remain reasonably large so certainty is low at this time. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 700 AM CDT Mon May 18 2026 Low stratus will persist across the area through the forecast period as a mid-level disturbance passes the area. For now, believe prevailing MVFR conditions are certain with periodic IFR conditions possible. Confidence in timing and coverage is low so will limit mention and monitor trends. Light precipitation in the form of rain may impact both terminals today, primarily LBF early then VTN closer to midday. Coverage will be spotty so impacts may be intermittent. CIGs should improve some over southwest Nebraska late but confidence in seeing anything greater than MVFR conditions remains low. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...NMJ LONG TERM...NMJ AVIATION...NMJ  802 FXUS63 KGID 181205 AFDGID Area Forecast Discussion National Weather Service Hastings NE 705 AM 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 /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 644 AM CDT Mon May 18 2026 For KGRI/KEAR Airports: A low deck of stratus will remain in place through the full day and night. MVFR ceilings this morning will soon drop into IFR ceilings (by 13-15z). IFR ceiling will likely remain in place until 22-4z, first lifting from KEAR over KGRI. A period of drizzle to light rain is possible to impact both terminals between 14 and 20z. There is a low-end chance for a thunderstorm to be in the KGRI vicinity between 22-2z. Otherwise, winds will remain out of a northerly direction through the day (340-030 degrees) with speeds sustaining near 15-20kts and gusting as high as 25-35kts. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ UPDATE...Stump DISCUSSION...Mangels AVIATION...Stump  880 FXUS63 KMPX 181206 AFDMPX Area Forecast Discussion National Weather Service Twin Cities/Chanhassen MN 706 AM CDT Mon May 18 2026 .KEY MESSAGES... - Another round of showers & thunderstorms tonight. Can't rule out a few strong to severe storms from far-southern Minnesota into western Wisconsin. -Seasonably cool & dry midweek. Rain chances return Friday. && .DISCUSSION... Issued at 253 AM CDT Mon May 18 2026 A few remnants showers & thunderstorms will linger over the area towards sunrise, but all of the active weather has moved well off to our east overnight. Cloud cover is expected to stick around through much of the day today, & cool northeast winds mean that temperatures may struggle to warm much out of the 50s & low 60s across much of central Minnesota. Farther east, portions of western Wisconsin will still remain ahead of the surface low/cold front & temperatures could reach the 70s this afternoon along with muggier dew points in the 60s. We'll stay dry for much of the day today, but another round of showers thunderstorms is expected to spread northeastwards out of the central plains this evening. We should north of the prime environment for severe weather across KS/NE/IA, but will have to watch just how far north a corridor of weaker surface- based instability can make it into far-southern Minnesota & western Wisconsin this evening. Expect scattered showers to quickly spread northwards across MN & WI during the early evening, with the heaviest rainfall & best chance for thunder coming between8 PM to midnight. Can't rule out a few strong to severe storms capable of damaging wind gusts across these areas, but otherwise we're just expecting your typical spring showers with a few rumbles of thunder at time. The most widespread concentration of thunderstorms, & heaviest rainfall amounts, are expected from southern Minnesota into west-central Wisconsin where rainfall amounts of 1-2" are likely. Elsewhere, the showers will be lighter & more sporadic so only expecting rainfall amounts on the order of 0.25-0.5". The showers & thunderstorms will continue on & off through the night, ending from west to east around sunrise. Much cooler weather arrives after the rain with temperatures struggling to warm out of the 50s Tuesday. Strong cyclonic flow & colder temperatures aloft will likely create a prime environment for isolated diurnally-driven showers during the afternoon, but rainfall amounts from these will be light. May need to monitor the potential for another frost/freeze Wednesday morning if clouds are able to clear out overnight & the radiational cooling potential is maximized. Seasonably cool & dry weather continues through Thursday with another chance for showers & thunderstorms looking likely Friday into Saturday. Additional chances for showers & thunderstorms look possible over the Memorial Day weekend, but it won't be a washout of a weekend. Temperatures return to more seasonable values Friday into saturday, & could warm into the 80s Sunday & Monday. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 706 AM CDT Mon May 18 2026 Predominately MVFR/IFR this period with SHRA/TSRA chances later this afternoon and evening. A line of showers between RNH and EAU will continue to move off to the NE. Cigs are expected to remain in either low MVFR and IFR through much of this forecast period. Surface low pressure centered over MSP is creating variable winds across all sites currently however winds ware expected to become NW'ly later this morning into the early afternoon. Did update previously stated prob30s to tempo groups where rain and thunder appeared most likely later this afternoon and evening. Precip should wrap up early tomorrow morning. KMSP...Not much change since the previous TAF issuance. VFR cigsare expected to fall to MVFR/IFR heights and linger there for much of the period. Converted and tightened up the previous prob30 mentions to a tempo for TSRA between 2 and 5z this evening. Variable winds will increase out of the NW between 5-10kts this morning with gusts eventually increasing to near 20kts after 10z tomorrow morning. /OUTLOOK FOR KMSP/ TUE...MVFR cigs becoming VFR. Wind NW 10-15G25kts. WED...VFR. Wind lgt and vrb. THU...VFR. Wind SE 10G20kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...ETA AVIATION...Dunleavy  632 FXUS61 KPBZ 181217 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 817 AM EDT Mon May 18 2026 .WHAT HAS CHANGED... As discussed below, there is now a conditional risk of strong storms/damaging wind gusts in portions of the region today. The risk for Tuesday is now focused to the northwest of Pittsburgh with a bit higher confidence. The rest of the forecast remains relatively unchanged. && .KEY MESSAGES... 1) Heat may impact sensitive populations early this week. 2) Highly conditional and localized severe wind risk today. A bit better chance of severe storms northwest of Pittsburgh Tuesday, and perhaps in the higher terrain Wednesday ahead of a cold front. && .DISCUSSION... KEY MESSAGE 1... The Atlantic coast/southeast CONUS ridge provides our highest 500mb heights of the week today, around 587/588dm across the Upper Ohio Valley. The lack of cloud cover for the most part across the region today will lead to efficient heating and likely the hottest temperatures. Heights begin to back off Tuesday as an Upper Midwest shortwave induces a downstream response of kicking the ridge axis further east. This, along with the potential for some afternoon clouds/isolated convection, makes temperatures a bit more uncertain. Continued to run a bit below the overly bias-corrected NBM mean suggestions for highs both days. Went with numbers closer to the LREF means overall, but did account a bit for strong sun/relatively dry ground. This leads to max values in the upper 80s to around 90 today for the majority of the region, with lower/mid 80s in the higher terrain. Went a degree or two lower Tuesday given the factors mentioned above. Urbanized valleys could crack into the lower 90s in the worst case both days. Record high values for today could be approached in higher-end scenarios. Record maximum low temperatures may also be challenged Monday night. The NWS heat risk shows mostly a moderate risk Monday into Tuesday, whereby heat may generally impact the most sensitive populations. Make sure to stay hydrated or monitor for signs of heat illness if spending excessive time outdoors. KEY MESSAGE 2... While the ridge is expected to largely suppress convective development via mid-level capping today, there are a couple of caveats. Localized convergence along the highest terrain of northern West Virginia could overcome the capping influence and take advantage of surface-based CAPE over 1500 J/kg to create isolated storms rolling northeast off of the ridges. With potential for DCAPE of 800-1000 J/kg, a brief window may exist for strong downburst wind, but the main risk area is off to our east where storms will have longer residence time. Also, a couple of the CAMS develop some isolated convection over eastern Ohio and/or southwest Pennsylvania during the late afternoon/early evening today, likely off of outflow from convection to our west. Confidence in this is quite low given the expected ridging, and no mention of precip was made for this for now, but hi-res trends should still be monitored. IF storms can manage to overcome the ridging here as well, there could be an isolated downburst risk here as well, mainly near/north of I-80 along the northwest side of the ridge. Potential for thunderstorms increases Tuesday, especially during the late day and evening, as the ridge breaks down and as a cold front advances into the Middle Ohio Valley. The most-likely scenario at this time involves convection forming to our west and flowing into the region mostly after 21Z, with a high DCAPE environment providing a downburst wind risk. The risk appears highest generally north and west of Pittsburgh, as storm strength should be on a downward trend through the evening with the typical loss of diurnal buoyancy. Models have the cold front near or just west of Pittsburgh by 12Z on Wednesday. This makes sufficient heating for strong convection highly questionable for the region, with any threat likely focused more towards the higher terrain, conditional on the development of adequate CAPE. A damaging wind threat would be most likely in any severe scenarios. Cooler temperatures behind the cold front will end any severe threat for the remainder of the week. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... High confidence VFR through the TAF period under the influence of high pressure east of the region. A few cu develops this afternoon with peak heating/mixing while southwest winds occasionally gust between 15-25kts (near 0% likelihood of exceeding 25kts). Any convective chances are tied to weak convergence along the WV ridgeline, with storms drift northeast, further cementing minimal terminal concerns. Nocturnal increases in the low-level jet may create brief periods of LLWS, but the lack of duration or meeting criteria (either by speed/direction or by height) led to an omission from TAFs. Area mid to high level cloud cover increases overnight into Tuesday morning in association with an eastward moving but decaying MCS. There is a non-zero chance for isolated showers and thunderstorms develop off its outflow near to after 00z around northwest PA but probability is too low for TAF mention. Outlook... Outside of an isolated afternoon thunderstorm Tuesday, VFR persists until an upper shortwave and surface front push a shower/thunderstorm axis east Tuesday evening through Wednesday afternoon. Initial restrictions will be tied to rainfall intensities with height falls not occurring until after frontal passage. High pressure and VFR returns by Thursday areawide before an active pattern feature multiple rain chances develops Friday into the weekend. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...CL AVIATION...Frazier/Lupo  588 FXUS62 KTBW 181215 AFDTBW Area Forecast Discussion National Weather Service Tampa Bay Ruskin FL 815 AM EDT Mon May 18 2026 ...New AVIATION... .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 322 AM EDT Mon May 18 2026 Currently at the surface, the sub-tropical ridge of high pressure is centered east of the Carolinas, and will largely hold in place through the week, keeping firm control on the weather pattern for the area. With the ridge to the northeast of Florida, east and southeast flow will result in above normal temperatures with highs topping out in the upper 80s to mid 90s each day through the forecast period. This flow pattern will also bring chances of mainly afternoon and early evening showers each day, mostly along sea breeze and outflow boundaries. For today, a pocket of dry air will move west off the Atlantic into northern Florida, prohibiting significant rain chances for areas north of Interstate 4. For the southern half of the area, more favorable atmospheric moisture will result in scattered to numerous shower and storms this afternoon, with the highest rain chances close to the west coast with the sea breeze collision. Tuesday through Thursday, deeper moisture will wrap back into northern Florida from the Atlantic, allowing for isolated to scattered storm chances over the northern half of the forecast area, while deeper moisture to the south will bring scattered to numerous storms each afternoon, with the greatest storm coverage just inland of the west coast in the late afternoon. Late in the week and into the weekend, a frontal boundary will stall out north of Florida, shifting the sub-tropical ridge slightly east. This will result in the flow pattern becoming weaker and slightly more southeasterly, shifting the highest rain chances farther inland than what will be seen earlier in the week. && .AVIATION... (12Z TAFS) Issued at 811 AM EDT Mon May 18 2026 Some drier air will be filter in to West Central Florida today limiting shower chances for our northern TAF sites. Higher moisture remain in Southwest Florida where we could see another round of scatter showers and isolated thunderstorms this afternoon and evening. Winds will be out the east with occasional gusts up to 20 knots. && .MARINE... Issued at 322 AM EDT Mon May 18 2026 High pressure will hold northeast of Florida through the week, with east and southeast flow continuing, turning onshore near the coast each afternoon with the sea breeze circulation. Winds and seas will generally hold less than headline criteria, although there is a chance for showers and thunderstorms moving west into the coastal waters each day during the late afternoon and early evening hours, causing locally higher winds and rough seas. && .FIRE WEATHER... Issued at 322 AM EDT Mon May 18 2026 A slightly drier air mass will shift west into northern Florida today, limiting rain chances north of Interstate 4 and dropping relative humidity to near critically low level this afternoon. South of I-4, humidity will be slightly higher, with scattered afternoon showers and storms. Moisture and humidity increases again on Tuesday, resulting in scattered to widespread showers and storms across the area in the afternoon. && .PRELIMINARY POINT TEMPS/POPS... TPA 92 75 92 75 / 20 10 50 10 FMY 93 74 93 74 / 50 20 70 20 GIF 92 72 91 72 / 20 0 30 10 SRQ 93 73 93 73 / 40 20 50 20 BKV 94 70 94 69 / 10 0 50 0 SPG 94 75 94 76 / 20 10 50 20 && Sea Breeze Thunderstorm Regime For Monday: 3 Sea Breeze Thunderstorm Regime For Tuesday: 3 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  664 FXUS65 KBYZ 181218 AFDBYZ Area Forecast Discussion...Updated National Weather Service Billings MT 618 AM MDT Mon May 18 2026 .KEY MESSAGES... - Frost/freeze this morning and Tuesday morning, coldest Tuesday morning. Make sure to protect sensitive vegetation. - Cooler and breezy with occasional chances of precipitation today. - Light snow accumulations (an inch or less) over the foothills this morning. Minor impacts to travel are possible. - Periods of light to moderate mountain snow today. Recreation could be impacted by winter conditions. - Another weather system brings the chance of precipitation Wednesday into Thursday. && .UPDATE... After a brief break overnight, light rain/snow is advecting north into southern portions of the area this morning as moisture and weak lift stream north. Expect a cool (highs in the 40s to low 50s), breezy and unsettled day today, with the greatest shower coverage over the southern mountains/foothills and far southeast MT as an upper low lifts north and east into the central Rockies. A few inches of additional snow accumulation is possible in the mountains, greatest on north aspects, with some slushy accumulations into the foothills (inch or less), greatest near the mountains. The Winter Weather Advisory for the Bighorn/Pryor mountains is in effect until noon today. Have updated temperatures and PoPs to latest trends through this evening. STP && .DISCUSSION... Today through Sunday... Today will be cool, breezy, and unsettled under the influence cyclonic flow aloft. With this, high temperatures will be in the 40s to lower 50s with brisk northerly wind gusts in the teens and 20s mph for most, with occasional 30s mph near the mountains and foothills. While there is at least a slight chance (15 percent or greater) of light precipitation across the area today, the best chance of more persistent precipitation is to the south near the Montana-Wyoming state line. With this, snow levels will be low enough to favor a rain and snow mix, with mostly snow during the morning hours over the foothills. This may lead to minor travel impacts for the morning commute along the Beartooth and Red Lodge foothills and the Sheridan foothills. However, accumulations are expected to remain relatively light with additional accumulations up to an inch mainly on grassy surfaces. Slick roads could also develop as temperatures drop below freezing tonight along the foothills. With that said, the Winter Weather Advisory remains in effect for the Beartooth and Red Lodge foothills to accommodate the potential for additional, potentially more robust snow shower development this morning. Precipitation gradually comes to an end late today, lingering the longest over far eastern Montana. A stray shower or two may even linger into early Tuesday morning over Fallon and Carter Counties (up to a 15 percent chance). Tuesday will be warmer with high temperatures in the 50s and 60s. While most areas will remain dry under shortwave ridging aloft, an isolated shower or two is possible over the mountains west of Billings during the afternoon (10 to 20 percent chance). Wednesday into Thursday, the chance of precipitation returns as another weather system and associated cold front move through the region. This cold front, expected to drop through the area sometime late Wednesday into early Thursday, looks to bring decent frontogenesis that could support at least scattered precipitation. With this, the chance of seeing any precipitation is currently 40 to 80 percent, greatest over south-central Montana and north-central Wyoming where upslope enhancement looks to be in play. The one potential issue to watch is that models are starting to show the system may split. If this happens, the best energy could dive south and limit the precipitation potential over our area. At this time though, models continue to provide enough frontogenesis and upslope enhancement to favor precipitation. As far as the precipitation type goes, precipitation would mostly be rain for the lower elevations and snow in the mountains with snow levels around 7000 feet. Friday into the weekend looks to remain unsettled with northwesterly flow aloft. While temperatures are currently advertised to warm back into upper 70s and 80s this weekend, temperatures may trend slightly cooler (more in the 70s) as potential weather systems moving through the northwesterly flow aloft are picked up in the models. Arends .AVIATION... Snow showers will continue to obscure the mountains at times today. Scattered rain/snow showers will impact foothill locations at times as well (KLVM and KSHR), with isolated rain showers over the plains. MVFR to local IFR conditions are possible with the showers, with widespread MVFR ceilings over the area as well. Look for conditions to gradually improve during the afternoon and evening with lifting ceilings and decreasing shower coverage for most areas. As skies clear and winds decrease overnight, some patchy fog is possible (20% chance) for central and eastern valleys. STP && .PRELIMINARY POINT TEMP/POPS... Tdy Tue Wed Thu Fri Sat Sun ------------------------------------------------------- BIL 050 029/067 043/071 043/063 042/071 045/079 050/084 2/W 10/U 01/B 75/T 11/B 00/B 01/B LVM 048 025/062 036/065 036/061 036/068 040/076 044/080 4/W 10/B 02/W 85/T 12/T 11/B 11/N HDN 050 026/067 037/073 041/064 039/072 042/079 047/083 2/W 10/U 01/B 65/T 22/T 10/B 01/B MLS 048 030/064 040/073 043/065 041/071 043/078 048/082 2/W 20/U 01/B 44/W 11/B 10/B 11/B 4BQ 045 029/062 038/072 043/062 040/068 043/076 048/081 5/W 20/U 00/U 26/W 22/W 10/B 01/B BHK 046 029/059 035/072 039/064 038/068 042/075 046/081 4/W 20/B 01/B 34/W 32/W 21/B 11/B SHR 043 024/060 031/067 036/058 033/067 036/075 040/080 8/W 10/U 01/U 47/T 23/T 11/B 01/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...Winter Weather Advisory in effect until noon MDT today FOR ZONE 171. WY...Winter Weather Advisory in effect until noon MDT today FOR ZONE 198. && $$ weather.gov/billings  775 FXUS63 KICT 181222 AFDICT Area Forecast Discussion National Weather Service Wichita KS 722 AM CDT Mon May 18 2026 .KEY MESSAGES... - Scattered to numerous thunderstorms this afternoon through overnight. All severe weather hazards possible, including large hail, damaging winds, a few tornadoes, and heavy rainfall. Greatest chances for severe weather will be over central KS. - Warm and windy today, with cooler weather tonight through Thursday. - Periodic on-and-off shower/thunderstorm chances Wednesday night through the weekend. A few bouts of strong to severe storms along with heavy rainfall are possible, but widespread severe weather potential appears low at this time. && .DISCUSSION... Issued at 305 AM CDT Mon May 18 2026 THUNDERSTORM CHANCES: PREDAWN HOURS--THIS MORNING...Remnant outflow boundary from current central-northeast KS thunderstorm complex is expected to lay out generally along the Highway 50 to Highway 54 corridor through this morning, before retreating back northward this afternoon. A strong low-level jet impinging on this boundary should support continued festering showers/thunderstorms across central and east-central KS during the predawn hours, shifting east into east-central KS and western Missouri this morning. Really like the HRRR's depiction of this activity, which keeps it mostly north of Highway 54. Thinking the primary concerns will be marginally severe hail (at worst) and areas of heavy rain and associated flooding concerns. MID-LATE THIS AFTERNOON--TONIGHT...Otherwise, attention then turns to this afternoon-evening, when a sharp dryline/cold front combo ahead of an ejecting shortwave trough will be the focus for scattered to numerous thunderstorm development. Thinking initiation will occur by 3-4pm over central KS, with storms expanding in coverage and spreading south-southeast during the evening and overnight. Further south, can't rule out an isolated dryline storm over south-central KS, but thinking those chances are lower given slightly more capping and weaker forcing. Strong to extreme fat instability coupled with 35-45 kts of deep layer shear oriented mostly parallel to the boundary should support a rather messy storm mode, with clusters of supercells early on gradually transitioning to linear with embedded supercell structures with time. Very large hail and damaging winds will be the primary threats before about 7-8pm, along with the potential for a few supercell tornadoes given strengthening low-level shear. Reason- being, it's during this time (i.e. 3-8pm) storms will have the greatest chance of being discrete or semi-discrete. Additionally, we could also see a handful of landspout tornadoes during this time across mainly central KS, given the expected strong low-level vorticity along the slow-moving boundary combined with the extreme buoyancy. As we head past 7-8pm or so, thinking the potential for both supercell and landspout tornadoes along with very large hail should start to decrease given the likely transition to mostly linear convection as the cold front picks up steam to the southeast, with the primary threats likely being golfball size hail or less, along with a damaging wind risk as storms trudge into south-central and southeast KS Can't rule out a few brief embedded tornadic circulations within this linear activity given the very strong low- level shear, but the overall tornado threat should lessen once the transition to linear storm mode occurs. Finally, another threat with this activity will be locally very heavy rainfall and associated flooding concerns, especially over central KS before 8pm when storms have the potential to train over the same areas due to the stalled nature of the frontal zone. WEDNESDAY NIGHT--WEEKEND...Periodic on-and-off shower/thunderstorm chances are possible mid week through the weekend, as a handful of low-amplitude shortwaves traverse Mid-America amidst returning low- level moisture. Thinking there will be some opportunities for strong to severe storms and heavy rainfall during this period, although widespread severe weather appears unlikely. There's quite a bit of uncertainty surrounding this period, stay tuned. WIND: Strong south winds will continue today, as low pressure continues to deepen to the west. Sustained winds of 25-35 mph with gusts up to around 45-50 mph are likely. Will continue the inherited wind advisory from mid this morning into this evening. TEMPERATURES: Southerly flow and above average heights/thickness will support continued above average temperatures through today, with overnight lows in the 60s to low 70s and daytime highs in the 80s and 90s. A strong cold front will blast south across the region tonight, supporting near to below average temperatures Tuesday through Thursday, with daytime highs in the 60s-70s and overnight lows in the 40s-50s. Deterministic and ensemble consensus shows a warming trend from late week through next weekend and beyond. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 713 AM CDT Mon May 18 2026 Cold front was beginning to stall out over central Kansas with low clouds in the IFR category over central Kansas early this morning. The low clouds look to linger into the early afternoon hours. Meanwhile low clouds in MVFR category will affect south central and southeast Kansas into the afternoon hours. Showers and storms over southeast Kansas will gradually diminish late this morning or early afternoon. Thunderstorms are expected to redevelop this afternoon along the stalled out cold front over central Kansas, some of them could become severe. The activity will then increase in coverage and spread southeast across the region tonight. && .ICT WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 10 PM CDT this evening for KSZ051>053- 067>070-082-083-091>094-098. && $$ DISCUSSION...ADK AVIATION...CDJ  530 FXUS65 KTFX 181245 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 645 AM MDT Mon May 18 2026 .KEY MESSAGES... - Mainly mountain showers today, with dry and cool conditions elsewhere. - Another cold night is in store tonight across the valleys of Southwest and Central Montana, with a high chance for a hard freeze. - Temperatures moderate through rest of the work week, but daily chances for showers exist. && .UPDATE... Lingering northerly flow aloft has resulted in a few areas of more persistent upslope snow in a few mountain areas. The only change this morning was to increase probability of precip and snow amounts in these areas through the remainder of the morning. Precipitation becomes more showery in nature this afternoon as daytime heating ensues, and largely looks to be confined to the mountains and adjacent areas. -AM && .DISCUSSION... /Issued 517 AM MDT Mon May 18 2026/ - Meteorological Overview: One final day of well below normal temperatures can be expected as cool, cyclonic northwest flow prevails over the Northern Rockies, with additional opportunities for predominately mountain precipitation, especially along the Rocky Mountain Front. By this afternoon upper level ridging over the Eastern Pacific will begin to amplify, with overall rising heights across much of the Western CONUS. While this ridge will amplify over the Eastern Pacific it will fail to build east and over the Northern Rockies through the work week, which will help to keep Southwest through North Central Montana beneath continued northwest flow aloft. While temperatures will moderate beneath the rising heights aloft there will be daily chances for showers and storms throughout the work week, especially from Wednesday morning through Thursday morning when a compact shortwave dives southeast and over the Northern Rockies within the aforementioned northwest flow aloft. This shortwave looks to bring the best chance for widespread precipitation this week, with most lower elevations seeing light rainfall up to 0.10" and the mountains seeing between 0.10" to 0.25". The exception to this will be the northerly upslope areas of Central Montana, Island Ranges of Central Montana, and Continental Divide where precipitation amounts of between 0.10" to 0.25" and 0.25" to 0.50" are possible for plain and mountain locations, respectively. This weekend the upper level flow will become quasi-zonal, which will lead to increasing surface winds and warming temperatures, with most locations climbing above to well above normal. - Moldan - Forecast Confidence & Scenarios: Cold Temperatures Tonight... Upper level ridging building in over the Northern Rockies combined with overall light surface winds and mostly clear skies will setup ideal radiational cooling processes across much of Southwest through North Central Montana tonight, with the exception of the immediate Rocky Mountain Front where southwest surface wind will be just strong enough to inhibit surface decoupling. With below normal temperatures already in place thanks to this weekends disturbance temperatures will cool efficient tonight; with a 50% or greater chance that values fall below freezing across most locations and 70% or greater chance for a hard freeze across most valley locations in Southwest and Central Montana. Those with early season gardening interest should be prepared to take protective measure for sensitive vegetation. Below is the NBM5.0 probabilities for certain temperatures for select locations across North Central, Central, and Southwest Montana tonight. Low Temperature Probabilities LOCATION <36F | <32F | <28F Browning 100% | 55% | <5% Cut Bank 95% | 60% | 20% Havre 100% | 80% | 40% Great Falls 95% | 60% | 25% Lewistown 100% | 100% | 85% Helena 85% | 45% | 5% Bozeman 100% | 100% | 85% Dillon 100% | 100% | 70% Ennis 100% | 100% | 90% West Yellowstone 100% | 100% | 100% Gusty Winds and Choppy Water this Memorial Day Weekend... Increasing south to west surface winds over the holiday weekend, specifically on Sunday and Monday, is likely to lead to choppy water conditions on area lakes, reservoirs, and long fetches of rivers. NBM5.0 probabilities for wind gusts in excess of 40 mph across most of Southwest through North Central Montana range from a 20-40% chance on Sunday and between a 40-60% chance on Monday, with the exception of the Rocky MOuntain Front where a 40-75% chance exists both days. Those with plans to recreate on waterways should be prepared for choppy conditions, especially considering that local waterways will be significantly colder than the ambient air temperature due to snowmelt. These choppy conditions and cold water temperatures will create an increased risk for drowning should a person fall into the water without proper safety equipment. - Moldan && .AVIATION... 18/12Z TAF Period Primary concern throughout the 1812/1912 TAF period will be the potential for fog at the KGTF and KCTB terminals through 14-16z this morning; however, confidence in this occurring is low so for now kept conditions to temporary MVFR with the potential for VLIFR/LIFR conditions. Otherwise IFR/MVFR/low-VFR CIGS will improve to low-VFR/VFR through 16-20z today. Mountain obscuration will persist through 00-06z tonight. - Moldan && .PRELIMINARY POINT TEMPS/POPS... GTF 52 29 63 40 / 10 0 30 10 CTB 54 31 63 38 / 20 10 20 10 HLN 55 29 62 38 / 10 10 20 0 BZN 51 22 60 34 / 10 0 10 0 WYS 41 16 51 24 / 10 10 20 0 DLN 48 23 60 30 / 10 10 20 0 HVR 54 26 66 41 / 10 0 50 10 LWT 46 23 59 36 / 40 0 30 0 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls  862 FXAK68 PAFC 181254 AFDAFC Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 454 AM AKDT Mon May 18 2026 .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)... Active weather continues across Southcentral Alaska as multiple waves and fronts move through the region. Rain persists along coast areas of the north Gulf coast and Kodiak Island through the early week. Western Susitna Valley and along terrain of the Copper River Basin will also continue to see precipitation through Tuesday afternoon. Lower elevation of the Mat-Su Valleys and the Copper River Basin, as well as Anchorage and western Kenai Peninsula will be on the drier side over the next couple of days. Gap winds, including Turnagain Arm, Knik, and Copper River, and winds along terrain will increase and become gusty this afternoon through Tuesday morning as the front approaches. Winds will gradually diminish through Tuesday afternoon as the front moves onshore and passes through. Another North Pacific low pushes into the southern Gulf of Alaska late Tuesday night, keeping the unsettled weather pattern in place for much of Southcentral through mid-week. KM && .SHORT TERM FORECAST SOUTHWEST ALASKA, THE BERING SEA/ALEUTIANS (Days 1 through 3)... Our Bering Sea low has drifted slightly westward this morning. Previously centered over the Pribilof Islands the low is now roughly 260 nautical miles to the west-southwest. Even with the westward jaunt the overall pattern remains the same. Smaller waves of low pressure continue to rotate through the base of the low, aided by a west-southwesterly upper-level jet directed into the Alaska Peninsula. Morning water vapor imagery depicts the current wave now tracking from the Alaska Peninsula into the Western Alaska Range. This wave is promoting isolated to scattered showers across much of the region. A second wave moves into Southwest Alaska later this evening/tonight and will maintain rain chances through Tuesday. Increasing southeasterly winds will also accompany the second wave tonight into Tuesday. Gusts will range from 15 to 25 mph for most areas, though winds coming out of the Kamishak Gap could gusts as high as 40 to 50 mph for Newhalen, Pedro Bay and Kokhanok. The biggest question for today entails a low chance for isolated wet thunderstorms. The threat remains highly conditional on breaks in cloud cover allowing for building instability this afternoon and evening. The passage of the next wave of low pressure into Southwest Alaska will be timed favorably during peak daytime heating while also providing some upper-level lift. Currently, thinking is that the best chance for any thunderstorms will exist across the northern tier of the Kuskokwim Valley from Lime Village to Crooked Creek, to Aniak and Lower Kalskag, wrapping westward to just north of Kasigluk and Tuluksak. Looking ahead, Wednesday has the potential to provide some relief from persistent rain across the region, as Tuesday's wave amplifies over the Gulf of Alaska and the next upper low moves into the western Bering. However, decreasing clouds may allow for stronger daytime heating and another threat for isolated wet thunderstorms during the afternoon and evening hours. -BL && .LONG TERM FORECAST (Days 4 through 7: Thursday through Sunday)... A broad upper-level trough over the Bering Sea extending into the Gulf will remain in place through the middle of next week. This will continue to support unsettled conditions across much of southern Alaska. By midweek, the focus shifts farther west as the active Bering Sea pattern continues. Another low is expected to move off Kamchatka and track eastward. Model guidance is now in better agreement, bringing the low across the Aleutian Chain before continuing into the Gulf of Alaska, remaining south of the mainland. Unsettled conditions will persist across the Aleutians as this system and its associated front progress eastward through the end of the week. LM && .AVIATION... PANC...VFR conditions will prevail through the TAF period. Strong southeasterly winds are expected continue, though the winds will not be as strong as yesterday. The cloud deck is expected to drop to 4k feet early this morning before increasing to 6k feet by late morning. There is a chance for showers at higher elevations, likely not making it to the airport due to the dry surface. There is a slight chance that low level wind shear will occur overnight tonight into Tuesday morning. && $$