665 FXZS60 NSTU 190108 AFDPPG Area Forecast Discussion National Weather Service Pago Pago AS 208 PM SST Mon May 18 2026 .Short term... TONIGHT THROUGH TUESDAY...Active thunderstorm activity remains over the Samoa Island chain due to a trough that lingered in the area since Saturday. WFO American Samoa reported near 6 inches of rain and counting from this time. As grounds have been saturated these past few days, we've received multiple reports of flash flooding across the territory. Model consensus had good handle on this event, forecasting peak convection Sunday and Monday (confirmed by surface observations). Latest satellite data shows these thunderstorms moving east southeast, following the movement of the trough, which is expected to shift further southeast by Tuesday. In the meantime, flash flooding conditions persist through tonight, with remnants of showers remaining into Tuesday morning. Strong winds that were observed over the weekend, have diminished today as the high pressure system producing these winds moved east. Variable winds up to 10 mph are currently observed, with winds gusting near showers and thunderstorms. .Long term... TUESDAY NIGHT THROUGH MONDAY... Showers will gradually diminish by Tuesday afternoon as the trough exists the region. However, the threat of landslides remain due to loose soil saturated by the heavy rain. Expect generally fair weather to remain through Thursday. However, a high pressure building to the south will slightly increase winds to 10 to 20 mph by Thursday afternoon, and shift winds south to southeast. Breezy winds and scattered showers will persist until the new week. && .Marine... Wave heights continue in the 7 to 9-foot range, even as winds have slightly diminished. This is due to nearby thunderstorms holding elevated seas through tonight. Expect the high surf and small craft advisory to remain in effect until Tuesday at the latest. As the trough exists the region Tuesday morning, ideal ocean conditions will persist through Thursday, before seas become a bit textured Thursday afternoon when winds increase up to 15 knots. .PPG WATCHES/WARNINGS/ADVISORIES... Flash Flood Watch High Surf Advisory Small Craft Advisory && $$ TM  119 FXUS61 KLWX 190113 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 913 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 continues 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 continues Tuesday. Convection from earlier this evening in the Alleghenies have now dissipated, with dry conditions tonight. Patchy fog is possible late tonight. Very mild conditions tonight as lows settle 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 /01Z TUESDAY THROUGH SATURDAY/... VFR conditions are expected to prevail across the terminals through Wednesday morning as high pressure strengthens offshore. 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 Fridaycould 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 to diminish late this evening. 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/KRR AVIATION...BRO/EST/SRT/KRR MARINE...EST/SRT/KRR  435 FXUS63 KJKL 190120 AAA AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 920 PM EDT Mon May 18 2026 .KEY MESSAGES... - Very warm and mainly dry weather will persist through Tuesday afternoon. - Showers and thunderstorms enter the forecast late Tuesday into Tuesday night, then persist through next weekend. - The switch to a wetter pattern yields temperatures closer to normal readings and produces a highly-beneficial, widespread wetting rainfall. && .UPDATE... Issued at 920 PM EDT MON MAY 18 2026 Added a slight chance of a shower to far eastern parts of the area as a few have snuck across the border from Virginia. These will be fleeting and probably be gone well before midnight. Cannot rule out a stray bolt of lightning from these for the next hour or so. These minor adjustments have been sent to the NDFD and web servers along with a freshening of the zones and SAFs. UPDATE Issued at 725 PM EDT MON MAY 18 2026 23Z sfc analysis shows high pressure to our southeast still in control of the weather over eastern Kentucky while a cold front is noted well off to the northwest. Strong storms are located closer to that boundary but will not make much progress toward the area through the night. However, they are pushing some high clouds and those may slow the temperature drop off this evening. Currently, temperatures are running in the very warm low to mid 80s. Meanwhile, amid southwest winds of 5 to 10 mph with some higher gusts, dewpoints are generally in the upper 50s to lower 60s. Have updated the forecast mainly to add in the latest obs and trends for the T/Td/Sky grids. These minor adjustments have been sent to the NDFD and web servers along with a freshening of the zones. && .SHORT TERM...(This evening through Tuesday night) Issued at 435 PM EDT MON MAY 18 2026 Late this afternoon an upper level ridge extended from the Southern Appalachians across the Carolinas to near Bermuda and another upper ridge was centered in the Gulf. Meanwhile an upper trough extended from Central Canada across Alberta and Saskatchewan to the Four Corners vicinity to the Southwest Conus. A couple of shortwaves were moving around the ridging and across sections of the mid MS Valley and the Lower OH Valley while a more substantial shortwave was working across sections of the Central Plains. At the surface, a ridge of high pressure extended from the Atlantic into parts of the Southeast and Southern Appalachians while a wavy frontal zone extended from the Northeast across sections of Quebec and Ontario to the northern and western Great Lakes to the Central Plains to Southwest Conus. Cumulus have developed during the heat of the day and temperatures are mild averaging between 10 and 15 degrees above normal highs for this time of year. Tonight and Tuesday, upper level ridging is expected to remain in place from near or north of Bermuda across the Southeast and into the Gulf. At the same time, a shortwave trough is expected to move across sections of the Central an Northern Plains and into the western Great Lakes through Tuesday morning and then to the Central Great Lakes through the remainder of the day. A general trend of rising 500 mb heights is expected through tonight with near neutral tendencies on Tuesday morning and then some height rises for the afternoon to early evening. Further 500 mb height falls are anticipated to end the period as the upstream shortwave moves to the eastern Great Lakes to Lower OH Valley. At the surface, the high pressure ridge will build into the Southern Plains tonight, before shifting to the south and southeast to end the period. As this occurs a sfc low tracks from the Plains across the Great Lakes and eventually to Ontario and Quebec while the trailing cold front will move into the Northeast and sag across sections of the OH Valley and into eastern KY. Dry weather should prevail through at least midday on Tuesday with the pattern favoring a modest ridge/valley split and temperatures in the coldest locations could fall a couple of degrees below the current forecast based on trends from last night and some mixed dewpoints near the 60 degree mark versus the lower 60s. Valley fog along the larger creeks, rivers, and lakes should form around or near midnight and then dissipate toward 9 AM EDT. With height falls on Tuesday afternoon, some convection cannot be completely ruled out during peak heating in the northwest half of the CWA and it is possible a larger areal extent of slight chance pops may ultimately be needed. Any stronger storm could produce gusty winds as there are some stronger gusts in the 18Z HRRR with some of the activity near peak heating. Better chances arrive later Tuesday evening and especially Tuesday night as the height falls continue and the front nears eastern KY. .LONG TERM...(Wednesday through Monday) Issued at 343 PM EDT MON MAY 18 2026 If the long term period could be summarized with just one word, it would be wet. The period will open with broad ridging over the southeastern US and troughing over the Hudson Bay. This will leave Kentucky in a regime of generally southwesterly flow aloft at the onset of the long term period. At the surface, a cold front will extend through the CONUS from a surface low centered over Quebec and push into eastern Kentucky on Wednesday, although the exact timing of the frontal passage remains dependent the upstream evolution of this system. The environment ahead of the front will be moist (owing to prefrontal southwesterly winds), but instability will be dependent on whether the timing of the frontal passage can align with maximal daytime heating. Accordingly, LREF guidance still shows a wide range of MUCAPE values, but the most likely outcome at this time is that instability should be sufficient for a few thunderstorms. Given that wind shear is expected to be meager, widespread organized severe weather appears unlikely. A few machine learning sources have introduced very low-end probabilities for gusty winds Wednesday afternoon, but this threat remaining highly conditional on favorable frontal timing, and thus confidence remains very low in this outcome. Regardless of storm strength, this system will bring much-needed rain to eastern Kentucky, which currently remains in drought (ranging from D1 conditions in our eastern forecast area to D2 and a pocket of D3 conditions in the western portion of forecast area). With broad ridging over the southeastern CONUS, the aforementioned cold front will struggle to push through into the Atlantic coast states and likely stall over the periphery of the ridge going into Thursday (TN area) before lifting into Kentucky again as a warm front on Friday. This pattern will bring multiple rounds of rain to the forecast area. As such, WPC has introduced multiple Marginal (Level 1 of 4) Excessive Rainfall Outlooks for the forecast area; one for our entire area on Wednesday, another for the Lake Cumberland area on Thursday, and a third for our entire forecast area again on Friday. QPF does not look overly impressive on any given day; LREF guidance shows that the chance of exceeding 0.5 of rain on any given day is low to moderate (maxing out at around 50% on Wednesday). However, this does not account for enhanced rain rates in any thunderstorms that do develop. If storms track over the same area for multiple days in a row, isolated instances of nuisance flooding cannot be ruled out. This is especially true closer to the KY/TN border, which will feel the greatest impacts of the stalling front. However, these details will need to be refined in the short term when convective rain rates can be better accounted for. Thursday looks to be the coolest day of the period. Following the frontal passage, CAA via postfrontal winds will keep maxTs generally below normal, with a defined thermal gradient over our forecast area as the front stalls. Currently, the NBM is outputting highs in the 80s for the southern portion of our forecast area; however, this appears to be an outlier compared to other guidance, so maxTs were bumped down a few degrees on Thursday afternoon to better account for the frontal passage. After the front lifts northward again, flow will become more southerly, and temperatures will be warmer than on Thursday. The NBMs highs in the upper 70s and low 80s may be slightly overdone given that rain is likely going into Friday afternoon (80-90% chance), but highs do represent an expected warming trend as the warm front lifts northward. Unfortunately (for outdoor activities) or fortunately (for drought relief), this weekend also looks to be quite wet even as the original front exits our area. A slow- moving upper level trough over the central CONUS, in addition to potential embedded impulses, will allow for rain chances every day through the weekend and into the end of the period. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 745 PM EDT MON MAY 18 2026 VFR conditions under times of high clouds will prevail through the period. The one caveat will be some valley fog between 04Z and 13Z with local MVFR and IFR reductions that are not expected to affect any of the TAF sites. Otherwise, south to southwest winds will average 6 to 12 kts with gusts to near 20 kts initially but diminishing through the evening. Light and variable winds will be the rule overnight, before becoming south to southwest at 5 to 12 kts again with some gusts up to 20 kts for Tuesday afternoon. By the end of the period, look for some cumulus to again develop between 4 and 6kft agl. && .JKL WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...GREIF SHORT TERM...JP LONG TERM...JMW/MARCUS AVIATION...JP/GREIF  771 FXHW60 PHFO 190128 AFDHFO Area Forecast Discussion National Weather Service Honolulu HI 328 PM HST Mon May 18 2026 .SYNOPSIS... An unstable and somewhat wet trade wind pattern will continue through Tuesday night, with brief downpours possible. From Wednesday into early next week, an area of high pressure north of the islands will push drier air the region and strengthen winds. The result will be a moderate to breezy trade wind pattern. && .DISCUSSION... Showers across windward and mauka areas, along with the Kona Districts on Big Island, were noted on radar this afternoon. Some showers have been producing moderate to briefly heavy rain, and this has resulted in the issuance of flood advisories on Kauai and on Big Island. These showers will trend down around sunset. Winds were averaging 10 to 20 mph with gusts 20 to 30 mph. Conditions remain on the humid side this afternoon as we await drier air that should arrive from Tuesday night into Wednesday night. Until that arrives, we will continue to see rather wet trades, meaning we will continue to have the chance for moderate to briefly heavy rain from showers. From late Wednesday onward, we will see noticeably lower PW values (down around 1 inch) going all the way into next week. Aloft, an upper level ridge will become established to our north, even as weak troughing will extend off the southwest coast of the mainland toward Hawaii. This troughing will have little to no impact on our surface weather, as the upper ridging will help keep relatively dry trades established over the region. Dewpoints will fall several degrees as the dry air comes in, allowing a little more cooling overnight for wind-sheltered areas. && .AVIATION... Moderate to locally breezy trades expected hold for the next couple days. Low cigs and SHRA will primarily impact windward and mauka locations with some limited spillover to leeward areas. Kona slopes of the Big Island will see low cigs and SHRA in the afternoon with some clearing overnight. MVFR conds possible in heavier SHRA, otherwise VFR prevails. AIRMET Sierra is in effect for mtn obsc for windward Kauai, Oahu, Maui and the entire area of the Big Island. Weak inversion heights are have kept moderate low level turbulence from developing this afternoon. Thus will hold off issuing AIRMET TANGO, but will continue to monitor over the next day or so as the atmosphere become more stable. && .MARINE... A surface high centered far northeast of the state will generate moderate to locally strong trades over the next few days. This anchored high will strengthen and expand during the second half of the week and will cause the trade winds to strengthen to widespread strong speeds with near gales over the windier zones around Maui County and the Big Island. A Small Craft Advisory (SCA) is currently in effect for the windier zones around Maui County and the Big Island. The SCA will expand in area later this week as the trades strengthen. A small size, short to medium period north northwest is expected on Tuesday. A Gale low developing in the North Pacific on Tuesday should send a small northwest to north northwest bump over the weekend. A series of small long-period south-southwest swells will provide surf near the summer average along south facing shores throughout the week. Strengthening trades later this week will bring an increase of short-period energy and will bring elevated surf along east facing shores by Thursday or Friday. Water levels peaking between 2.5 to 3.0 ft MLLW during today's high tides may result in some minor overwash within low lying coastal areas this afternoon. && .HFO WATCHES/WARNINGS/ADVISORIES... Small Craft Advisory until 6 AM HST Wednesday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel. && $$ DISCUSSION...Parker AVIATION...Almanza MARINE...Kino  357 FXUS63 KMKX 190144 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 844 PM CDT Mon May 18 2026 .KEY MESSAGES... - Another round of showers and storms late tonight into Tuesday with a small potential for strong to severe storms. - Cool and drier weather then returns for midweek. - Rain chances return Friday (45-55%), followed by a gradual warming trend Saturday into early next week. && .UPDATE... Issued 844 PM CDT Mon May 18 2026 The strong to severe MCS over south central IA will once again encounter much greater MLCIN and high LFCs as it continues newd toward the MS River. Thus a dissipating MCS will likely move into sw WI after midnight. However, still expect fairly widespread showers and sct storms to move across all of srn WI during the early morning hours as a sswly low level jet of 40 kts increases warm, moist advection and boosts elevated CAPE to 1000-2000 J/KG. Wind gusts will be the main concern with any storms. A wave of low pressure along the stationary front over IA will track newd to west central WI by 06Z then near Lake Superior by 12Z Tue. The low will then track ewd into Quebec during the day with its trailing cold front moving across srn WI Tue AM into the early afternoon. Moist low levels and marginal instability could result in a broken line of showers and isold storms along the front but no severe wx is anticipated. Gehring && .SHORT TERM... Issued 200 PM CDT Mon May 18 2026 Late this afternoon through Tuesday night: Quiet weather largely expected the rest of the afternoon into the evening with remnant convection moving off to the east with quite a bit of clearing ongoing right now ahead of developing storms to the southwest this afternoon and evening. This is what we will be monitoring tonight as it pushes into the CWA. Based on the development of this convection will in part determine how things play out tonight. Several models favor development and progression into a QLCS with a eastward progression. Most models have this potentially becoming elevated in addition to limited instability. As this pushes east toward southeast WI CAMs largely have this falling apart with very limited instability and very likely an elevated system at that point, which would reduce severe risk to essentially zero. However, it is worth mentioning that clearing this afternoon has definitely increased our severe risk as we will likely be able to hang on to a bit more instability and may avoid storms immediately becoming elevated as they reach the CWA. The best severe risk for tonight will be in southwest WI, likely southwest of Madison, with decreasing risk further east. We will need to monitor storms to the southwest tonight as the development and progression will play a role in determining the potential for severe storms later tonight. The remnant storms and precip will push out by mid morning with our attention turning to the cold front that will closely following the exiting precip. There is a mild concern for developing storms along the front but with departing storms in the morning it does not appear there will any recovery time ahead of the front with models suggesting very limited instability and frankly not a great shear environment either. This suggests that event should week storms develop they would not likely be of concern. The front should push in by the late morning and push through all of southern WI by early to mid afternoon. The best chance for weak storm development with the front is likely in southeast WI where the best chance for recovery would be. Otherwise, expect quiet conditions into the late afternoon and overnight as winds turn northwest behind the front with higher pressure gradually pushing behind it. Kuroski && .LONG TERM... Issued 200 PM CDT Mon May 18 2026 Wednesday through Monday: Cool and dry weather expected Wednesday and Thursday, with strong high pressure passing overhead and northeast to east winds off of Lake Michigan (around 10 to 15 MPH at times). Much of eastern WI should see highs in the 50s, with low to mid 60s further west. Some much needed calm and quiet weather. Our next noteworthy chance for precipitation arrives Friday, with roughly half of the available model guidance resolving a low pressure system tracking northeastward from the Great Plains and approaching our region. The favored track of this system would stall it either to our south or our west, with the continued onshore flow from Lake Michigan helping to reduce instability and prevent substantial moisture return over southern WI. Hence, we only forecast slight chances for thunderstorms Friday, with rain chances increasing from 15-55% in a southwest to northeast manner as the day goes by. As with any low pressure system this time of year, we will have to keep an eye on it's track and evolution, but ensemble consensus strongly suggests insufficient moisture return / instability for much in the way of thunder. Predictability drops substantially for Saturday and onwards, but the general consensus is a warming trend that continues into early next week. Sheppard && .AVIATION... Issued 844 PM CDT Mon May 18 2026 VFR conditions this evening then numerous showers and scattered storms during the early morning hours. Areas of MVFR Cigs and Vsbys may linger after the rain. More widespread MVFR Cigs will then overspread srn WI just after sunrise and ahead of the approaching cold front. Localized Cigs below 1 kft are possible over south central WI. The Cigs will dissipate after the cold frontal passage from mid to late afternoon. Gusty swly winds to 30 kts are expected on Tue especially over ern WI. Gehring && .MARINE... Issued 844 PM CDT Mon May 18 2026 A Dense Fog Advisory is in effect tonight through Tuesday morning for the north half of the lake as relatively mild and humid air flows over the cold lake waters. Otherwise modest to breezy southerly winds will develop tonight and last into early Tuesday afternoon, then followed by the passage of a cold front. Winds will shift to northwesterly with the cold frontal passage and remain a bit breezy. Scattered thunderstorms can be expected over the central and southern portion of the lake late tonight into Tuesday. High pressure around 30.4 inches will then move into the northern Great Lakes for Wednesday afternoon into Thursday. Light and variable winds taking hold from late Wednesday into Thursday. A Small Craft Advisory is in effect from Sheboygan to Winthrop Harbor from early morning Tuesday into the afternoon for breezy southwest winds. Gehring && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...4 AM Tuesday to 4 PM Tuesday. Dense Fog Advisory...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ868 until noon Tuesday. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, X, and YouTube at: www.facebook.com/NWSMilwaukee www.x.com/NWSMilwaukee www.youtube.com/NWSMilwaukee  586 FXUS63 KLOT 190146 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 846 PM CDT Mon May 18 2026 .KEY MESSAGES... - A period of showers and embedded thunderstorms is expected after midnight tonight through early Tuesday morning, some of which could be locally strong, mainly west of I-55. - Additional thunderstorms may redevelop Tuesday afternoon, mainly east of I-55, some of which could be strong to severe. - Summer-like warmth and breezy winds will prevail through Tuesday, then cooler temperatures and dry conditions will return for the middle of the week. - Milder weather returns heading into the weekend with intermittent shower/thunderstorm potential. && .UPDATE... Issued at 846 PM CDT Mon May 18 2026 A robust line of convection from Wichita, Kansas to Des Moines, Iowa, which created quite the severe event in the Central Plaines this evening, is slowly moving east. A strong instability gradient from northwest Missouri toward St. Louis should focus most of the strongest parts of the line's movement through the overnight south of the forecast area toward central Illinois. However, a plume of better lapse rates into central Iowa will slowly meander east ahead of the line of storms. Outflow from the storms should provide sufficient forcing, but being in a diurnally unfavorable time of day, the lapse rates should start to weaken by the time it approaches the Rockford Metro after midnight, but confidence lowers in coverage toward the city of Chicago as it starts to fall apart away from the better forcing. Most of the forecast area will be dry tomorrow morning, but lingering showers may crop up. The cold front will finally make it to the forecast area and turn winds from the southwest to the west and eventually northwest behind the front. Additional showers and storms are possible along the front, with the best time being in the afternoon. But by that time, the front could already be around and east of Interstate 55. Storms along the front in the afternoon could be strong to even severe with damaging wind and hail the primary severe threats. Forecast updates this evening were focused on the near-term timing of shower and thunder as well as for tomorrow afternoon. DK && .DISCUSSION... Issued at 244 PM CDT Mon May 18 2026 Through Tonight... Convection and associated MCV responsible for this morning's severe weather has moved into Lower Michigan. Air mass in the wake of this wave is substantially more stable and combined with modest height rises in its wake should prevent any renewed convective development this afternoon or evening. Severe convection currently developing over the central Plains is likely to congeal into a large QLCS that will move toward the mid-Mississippi Valley tonight. Most intense convection is likely to focus farther southwest across Missouri, likely intercepting the low level jet and orphaning the convection farther north across Iowa. This should result in convection over Iowa diminishing as it moves eastward into northern IL with some guidance suggesting very little shower activity would actually make it into our CWA. Have reflected this trend in pop grids, but opted to maintain at least chance pops given the inherent uncertainties in forecasting convective evolution. Pressure field is recovering in the wake of the morning convection which has allowed winds to pick and become rather gusty from the southwest. Gustiness of the winds will generally tend to abate by sunset, except perhaps remaining somewhat gusty tonight in the urban heat island of Chicago. -Izzi Tuesday... Convectively induced vorticity maximum will slide through northeast Illinois into early Tuesday, well outpacing the cold front, and therefore we may have some showers hanging on into the area, but confidence is medium-high that thunderstorm coverage will be on the lower side. Any lingering MCS cold pool footprint and residual cloudiness will likely delay destabilization into midday Tuesday, though additional storm development appears somewhat probable across the southeast half of the forecast area Tuesday afternoon/evening as the cold front finally pushes through the forecast area. Southwesterly flow ahead of the front will maintain mid to possibly upper 60s dewpoints and support MLCAPE approaching 1500 J/Kg. Stronger mid-level flow on the southeastern periphery of the Model guidance would support some additional vorticity maximum riding along the front, and flow to the southeast of the mid level trough across the northern Great Lakes will likely support enough storm development and some organization for a hail/wind threat during this time. This would be favored along and southeast of I-55, with short term ensemble guidance suggesting the window for much of NE IL and NW IN being fairly limited in the mid to late afternoon. For the Chicago metro area the picture is also a bit muddled for precipitation chances. High res guidance is mostly dry for the area, whereas global guidance and NAM/RAP does bring some shower activity across Chicagoland along the front in the early afternoon. KMD Wednesday onward... 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 /00Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 656 PM CDT Mon May 18 2026 Key aviation forecast messages: - Decaying line of SHRA/TSRA may move through overnight into early Tuesday AM (>30% chance). - Breezy SSW winds turn W Tuesday AM then NW by the evening. Made some timing adjustments to the overnight showers and thunderstorm potential based on latest model guidance and upstream storm evolution. Main change was to speed up the PROB30 start time by a couple hours for all sites, now 6Z RFD, 7Z DPA, 8Z ORD/MDW, and 9Z GYY. This is mainly tied to the line of storms currently racing east across southern Iowa toward the area. There remains a weak signal for isolated thunderstorms developing ahead of this feature between roughly ~4-8Z, however, confidence in this occurring remains low owing to only very subtle forcing mechanisms for lift within the increasing elevated instability (<30% chance). The potential for thunder is locally highest toward RFD where TSRA has been maintained in the PROB30. Can't rule out TS as far east as the Chicago terminals but the line will likely be decaying even further with eastward extent. A second round of showers and thunderstorms is expected during the afternoon on Tuesday but this activity should remain southeast of the terminals in areas mainly east of I-55 and south of I-80. Wind gusts this evening may subside briefly with sunset but are expected to remain at least sporadically gusty through the rest of the overnight hours around 20-25 kt out of the SSW. Winds then trend westerly behind the early AM showers and then northwest late afternoon/early evening. A period of MVFR CIGs are possible in the wake of the AM showers/storms and associated cold front into the afternoon. Highest coverage is favored out toward RFD and they may expand east into the metro toward midday, though confidence is not high enough to include in the Chicago TAFs with this update. Petr && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory from 6 AM to 4 PM CDT Tuesday for the IL and IN nearshore waters. && $$ Visit us at weather.gov/chicago  763 FXUS61 KRLX 190150 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 950 PM EDT Mon May 18 2026 .WHAT HAS CHANGED... Made a quick update to PoPs into early tonight. Overall, dry conditions are expected going forward outside of a few isolated showers/storms in southwest Virginia and far southern West Virginia over the next couple of hours. Further northwest, activity across southwest Ohio continues to become progressively more outflow dominated, which will lead to continued weakening as it gradually approaches our northwest CWA, where an isolated shower early tonight cannot entirely be ruled out. 830 PM update... Aviation Forecast Discussion update. 216 PM update... 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 /01Z TUESDAY THROUGH SATURDAY/... Widespread VFR conditions will largely prevail through this TAF period (until 00Z Wednesday). Scattered mid/upper level clouds are expected tonight amid dry conditions. Some very patchy river valley fog cannot entirely be ruled out across eastern/southern WV, potentially affecting EKN, although confidence in this occurring is quite low. Mainly dry conditions then continue during the day on Tuesday, with just the potential for a few ISOLD afternoon/evening showers or storms across the Mid-Ohio Valley. A FEW/SCT (035-050) Cu field is expected to develop late Tuesday morning into the afternoon. Calm or very light southerly flow is expected tonight, with southwest flow during the day on Tuesday. Breezes of 15-25 kts are expected at times from late morning onward, especially central/north. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z WEDNESDAY... FORECAST CONFIDENCE: High. ALTERNATE SCENARIOS: Brief MVFR or worse restrictions could occur at EKN later tonight if fog development is more than expected. 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. DATE TUE 05/19/26 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 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 00Z WEDNESDAY... Patchy IFR is possible in convection Wednesday through the weekend. && .Climate... Several record high temperatures were set or tied on Monday. Observed / Prior Records ---------------------------------- CRW | 93 (Record) / 92 (1962) | HTS | 92 (Tied) / 92 (1906) | BKW | 88 (Record) / 87 (1962) | EKN | 90 (Record) / 89 (1911) | ---------------------------------- Record high temperatures could also be challenged on Tuesday. Forecast / Record Highs ---------------------------- CRW | 92 / 95 (1931) | HTS | 91 / 92 (1996) | CKB | 90 / 90 (1959) | PKB | 91 / 90 (1964) | BKW | 87 / 89 (1996) | EKN | 87 / 93 (1996) | ---------------------------- && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ DISCUSSION...JP/GW AVIATION...GW CLIMATE...GW  876 FXUS64 KTSA 190153 AFDTSA Area Forecast Discussion National Weather Service Tulsa OK 853 PM CDT Mon May 18 2026 ...New UPDATE... .KEY MESSAGES... Updated at 851 PM CDT Mon May 18 2026 - Windy with isolated to scattered showers and storms through this evening. Limited severe risk. - Numerous showers and storms Tuesday morning into NE OK spreading southward through early afternoon. Severe weather possible along with locally heavy rainfall. - Cooler temperatures Wednesday-Friday with continued low rain chances through the remainder of the week. && .UPDATE... Issued at 851 PM CDT Mon May 18 2026 Updated pops for late tonight and Tuesday morning to reflect a bit faster movement of the convective line into and through the forecast area. The main severe weather threat in our area will likely be damaging winds, with the greatest severe weather threat near the Kansas border after midnight tonight. && .SHORT TERM... (Through tonight ) Issued at 1119 AM CDT Mon May 18 2026 Moist and unstable southerly flow remains in place across the area. Modest lift within the warm advection in the lower levels of the atmosphere is and will continue to result in isolated to scattered showers and storms the next few hours, particularly in far northeast OK and northwest AR. These storms will mostly stay sub severe, but some marginally severe hail is possible in the stronger storms. A few CAMs suggest storms could form along the dry line in western Oklahoma this afternoon, with storms then moving east into the forecast area, though this remains the less likely outcome. If these dry line storms did develop, these storms would have the potential to be severe. Otherwise, warm, humid, and windy conditions will persist through the day with highs reaching the mid to upper 80s. Near the tail end of the overnight hours a cold front will move into northeast OK. CAMs disagree on the storm details, but the most probable outcome is for a line of storms to be present along the front. Significant severe weather may occur north of the area, but the expectation is that the storms will be weakening at least somewhat as they approach the area. There are several reasons for this, including relatively weak upper level forcing and weak flow. Still, there will be a threat for strong damaging winds and an isolated tornadic spin up, particularly as storms first enter from Kansas. Areas of heavy rainfall may occur as the storms move through. && .LONG TERM... (Tomorrow through Monday) Issued at 1119 AM CDT Mon May 18 2026 Near dawn on Tuesday the line of storms will be moving through northeast OK, continuing southeast through the early afternoon before exiting the area. Wind shear will remain unimpressive, but there will be sufficient instability with daytime heating for a few storms to become severe. Large hail and strong gusty winds will be the main hazards, with a lesser tornado threat. Behind the cold front temperatures will quickly cool with much drier air. Most guidance is producing a renewal of showers and possibly a thunderstorm north of I-40 Tuesday evening. This will occur along an elevated frontal boundary remaining over the area. Wednesday will be cool and quiet outside of a few showers lingering for southeast OK and northwest AR. Highs will only reach the 70s Tuesday and Wednesday, perhaps even upper 60s in some spots. Lows will be in the lower 60s and upper 50s. A shortwave trough will dive into the area from the northwest Thursday to Friday, interacting with some remnant troughing across the desert Southwest. This will result in an increase in shower and thunderstorm activity across the area. With modest but sustained forcing, high PWAT, and a deep layer of minimal CAPE, this will be a good setup for several rounds of moderate rain, with only minimal severe weather risk. Over the weekend and into early next week it gets a little more uncertain, as models aren't confident on whether we get a short term break and warm up and dry out a bit, or if the remnant southwest troughing will keep shower activity going. Either way, if there is a break, it will be short lived with another storm cycle likely into the middle of next week. Overall, it appears somewhat cooler and wetter weather will be here to stay for a while. && .AVIATION... (00Z TAFS) Issued at 635 PM CDT Mon May 18 2026 VFR conditions will prevail this evening, with LLWS at all sites until the arrival of a cold front late tonight and Tuesday morning. A line of thunderstorms is expected to accompany the cold front, with reduced ceilings and visibilities and gusty winds. Gusty south winds ahead of the cold front will become north Tuesday, with gusts up to 20 knots through the day. MVFR ceilings will prevail through the day Tuesday following the passage of the cold front. && .PRELIMINARY POINT TEMPS/POPS... TUL 67 75 58 71 / 70 70 80 40 FSM 72 84 65 80 / 10 90 70 70 MLC 73 82 61 77 / 10 80 70 50 BVO 61 71 53 69 / 80 40 60 20 FYV 72 80 60 74 / 30 80 80 60 BYV 72 81 59 70 / 30 90 90 60 MKO 71 78 59 73 / 30 90 70 50 MIO 67 74 56 68 / 70 80 70 30 F10 70 78 58 73 / 30 80 70 50 HHW 73 81 65 79 / 10 90 60 60 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...Wind Advisory until 9 PM CDT this evening for OKZ055>064-067-154- 254-354. AR...None. && $$ SHORT TERM...06 LONG TERM....06 AVIATION...05