385 FXUS66 KLOX 190301 AFDLOX Area Forecast Discussion...UPDATED National Weather Service Los Angeles/Oxnard CA 801 PM PDT Mon May 18 2026 .SYNOPSIS...18/539 PM. Warmer temperatures are expected this week with some locally breezy Santa Ana winds at times through Tuesday morning. The warmest day will be Wednesday with slow cooling the rest of the week along with a return of night and morning low clouds and fog. && .SHORT TERM (MON-THU)...18/800 PM. ***UPDATE*** The story of today is the development and rapid spread of the Sandy Fire, which began this morning in Simi Valley. Under the influence of the weak to moderate Santa Ana Wind event on the heels of a prolonged warm and dry period, the fire quickly burned to the southwest. At the onset of this afternoon's rapid wind shift to onshore southwest to west winds, the fire quickly switched direction and further intensified. There have been a myriad of Evacuation Orders and Warnings, so please follow the advice of your local emergency officials. Additionally, two other fire starts occurred, one in the Antelope Valley, and one in the Angeles National Forest. These fires were contained relatively quickly. Onshore winds will weaken through tonight and winds will become relatively mild. Then another round of (slightly weaker) Santa Ana winds is forecast to begin Tuesday morning across wind prone mountains and valleys of Los Angeles and Ventura Counties. For the Sandy Fire specifically, winds are forecast to rapidly increase from the northeast in the morning hours between 8-6am, peaking from 8am-12pm. Another pronounced shift to onshore is expected tomorrow afternoon, this time an hour or two early that today. Another day of widespread elevated to locally brief critical fire weather conditions will be common across aforementioned areas. ***From Previous Discussion*** Another offshore push (although slightly weaker) is expected to develop tonight through Tuesday afternoon with wind gusts in the 30-40 mph range across the mountains, and 15-30 mph across the valleys and potentially the eastern edge of the Oxnard Plain. This mornings onshore push surfaced across the valleys and even some coastal areas. The Sandy Fire broke out this morning in Simi Valley and quickly burned through grassy hills due to gusty northeast Santa Ana winds. Even with slightly weaker winds, there again is an elevated threat for fire weather conditions tomorrow thanks in part to a prolonged warm and dry period. Winds will shift onshore Tuesday afternoon. Onshore flow will become more prominent Wednesday, increasing Thursday. Not expecting any marine layer coverage again until possibly late Tuesday through Wednesday, but more likely Wednesday night into Thursday morning as onshore flow becomes more pronounced. There is a very small chance that southern LA County, specifically the Long Beach area, sees low clouds and fog late tonight into Tuesday morning. Expecting all coastal areas and even some lower valleys to become entrenched in marine layer cloud coverage by Thursday night into Friday morning. High temperatures will increase 3-7 degrees tomorrow, and another degree or two in most areas Wednesday. By Wednesday, highs in the mid to high 80s will be common across coastal and interior valleys, with low 70s to low 80s common across coastal areas. A cooling trend begins Thursday on the coastal side of the mountains, while the interior will continue to warm a few degrees. .LONG TERM (FRI-MON)...18/1234 PM. A fairly quiet pattern will continue through the remainder of the forecast period, with weak winds aloft. Aside from a slight decrease in temperatures Friday and possibly Saturday, there will be little change in sensible weather day-to-day. Widespread temperatures in the 70s to low 80s will be common acrosscoastal valleys and basins, slightly cooler at the immediate coasts with mid 60s to low 70s likely. Inland valleys will see highs reach the mid to upper 80s, with low 90s possible, especially Friday. A more robust marine layer is likely to develop each night through morning, with some coastal areas struggling to clear each day. Marine layer clouds will try to move into some of the coastal valleys by this weekend, as onshore flow increases into the weekend. Onshore flow will then stay relatively steady through Monday. Moderate southwest winds across the Antelope Valley and foothills by this weekend, which would lead to elevated fire weather concerns each afternoon in the far interior. && .AVIATION...19/0038Z. At 1633Z at KLAX, the marine layer was 1000 ft deep, with an inversion up to 2600 ft and a maximum temperature of 19 C. Moderate to high confidence in TAF package. Wind speeds may be off by up to 5 kts during peak winds, and wind shift may be off by 1 hour. There is a chance of a few hours of MVFR conds at KSMO (40%), KOXR (20%), KSBA/KSMX(15%), and KCMA/KBUR/KVNY (10%) between 10Z-16Z Tue. There is a 25% of no flight cat restriction developing at KLAX and KLGB. KLAX...High confidence in VFR conditions through at least 06Z Tuesday. Moderate chance of CIGs between OVC010-020 from 10Z-16Z Tuesday, with a 25% chance of no flight cat restriction developing through the period. The east wind component is expected to be 4 kt or lower. KBUR...Moderate confidence in TAF. Wind speeds may be off by up to 5 kts during peak winds, and wind shift may be off by 1 hour. There is a 10% chance of a few hours of OVC008-020 cigs from 10Z-16Z Tue. && .MARINE...18/754 PM. For the Outer Waters, high confidence in current forecast. Small Craft Advisory (SCA) level winds will linger into tonight, dropping below SCA levels by early Tuesday morning. Then Tuesday through Friday, winds and seas are expected to remain below SCA levels, except for localized pockets of near SCA NW winds during the afternoons and evenings. For the Inner Waters north of Point Sal, high confidence in current forecast. There is a 50 percent chance of SCA winds on Wednesay afternoon/evening. Otherwise through Friday, winds and seas are expected to remain below SCA levels. For the Inner Waters south of Point Conception, high confidence in current forecast. This evening into tonight, localized near SCA winds may occur. Then local SCA winds may occur again Tuesday and Wednesay evening off the coast of Point Dume, across the San Pedro Channel, and in the Santa Barbara Channel. Otherwise through Friday, winds and seas are expected to remain below SCA levels. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for zones 670-673-676. (See LAXMWWLOX). && $$ PUBLIC...Lewis AVIATION...Schoenfeld MARINE...Black/Schoenfeld SYNOPSIS...LP/MW weather.gov/losangeles Experimental Graphical Hazardous Weather Outlook at: https://www.weather.gov/erh/ghwo?wfo=lox  961 FXUS64 KHUN 190311 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 1011 PM CDT Mon May 18 2026 ...New NEAR TERM, SHORT TERM, LONG TERM... .KEY MESSAGES... Issued at 1010 PM CDT Mon May 18 2026 - Low to medium chances (30-60%) of showers and thunderstorms return late Tuesday. - Medium to high chances (50-90%) of showers and thunderstorms then persist each day from Wednesday through much of the weekend. No severe weather is forecast. && .NEAR TERM... (Rest of Tonight and Tuesday) Issued at 1010 PM CDT Mon May 18 2026 Currently watching as a few showers/storms, remnants of outflow boundaries to our south, move from central Alabama up into Cullman County. These may eventually progress into Morgan and Marshall counties late this evening if they hold together. Overall, not anticipating much out of this activity other than some light rainfall and perhaps some lightning (no severe weather). With the loss of daytime heating, these are forecast to gradually dissipate over the next hour or so, as has been the trend the last several radar scans. Otherwise, expect a warmer night as lows only decrease into the upper 60s to lower 70s (cooler over the higher terrain of northeast Alabama). Confidence is low in the occurrence any patchy fog development, with winds around 5 knots continuing overnight and clouds on the increase later tonight as well. Upper level southwest flow will continue on Tuesday, along with surface high pressure to the east over the Carolinas. Although, an cold front looks to progress over the mid-Mississippi River Valley by late afternoon. There are very low chances (less than 10%) of showers and storms over far northwest Alabama Tuesday afternoon. In fact, with the cold front expected to still be well to our west by late afternoon, most shower and storm activity should hold off until the evening. Therefore, partly cloudy skies will continue yet again tomorrow with warm temperatures - highs in the upper 80s to around 90 degrees! && .SHORT TERM... (Tuesday Night through Thursday Night) Issued at 1010 PM CDT Mon May 18 2026 Southwest flow will persist aloft through late week, with subtle shortwaves rippling along the flow during this time. In addition, the aforementioned surface cold front over the Mississippi River Valley will slowly progress southeast over the Tennessee Valley. This feature looks to then meander over the region for several days (through late week). This overall pattern will keep daily chances (50-90%) of showers and storms in the forecast from midweek into the weekend. To put the wet conditions into perspective, model PWATs generally range between 1.5-1.8 inches through the short term period. When compared with Sounding Climatology from Birmingham, these values are right around to just over the 90th percentile (1.6 inches) for May 20th and 21st. Therefore, showers and storms will be efficient rainfall producers. With daily rain chances through late week, we'll need to keep an eye on which areas receive rainfall and if it's repetitive, which would increase the localized flood risk. Currently, the Weather Prediction Center has most of north Alabama and southern middle Tennessee in a Marginal Risk (level 1/4) of excessive rainfall and this continues through late week. Remember, if you encounter flooded roads, Turn Around Don't Drown! As for the potential for any severe storms, while instability looks to be sufficient, confidence is low in the development of severe storms due to the continuing trend of low bulk shear values by guidance (especially on Wednesday). The main concerns are more likely to be lightning and localized flooding through Thursday. As for temperatures, the increased rain chances will temper values, resulting in highs only reaching the lower to mid 80s by Thursday. Lows will generally remain in the 60s, due to elevated moisture. && .LONG TERM... (Friday through Monday) Issued at 1010 PM CDT Mon May 18 2026 A more summerlike pattern will persist through the Day 4-7 period as 5h ridging builds farther into the southeast U.S. and eastern Gulf of America. Southwesterly flow will persist northwest of the ridge, maintaining a moist flow of air into the Gulf States, particularly in the lower MS Valley where 2.0+ inch PWs will reside. Although, there is a corridor of slightly lower values in the 1.5-1.8 inch range over AL into eastern and middle TN, with higher values farther east across the FL peninsula through GA and the Carolinas. Multiple weak impulses will lift northeast through this period, with medium to high chances of showers and thunderstorms each day (diurnally inflated due to heating). High temperatures will be in the lower to middle 80s, with lows in the 60s. Dew points will be in the 60s to around 70 degrees. && .AVIATION... (00Z TAFS) Issued at 443 PM CDT Mon May 18 2026 VFR flight weather conditions are forecast. After 15Z Tuesday, southerly flow will increase to ~10kt with gusts of 15-20kt. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...26 SHORT TERM....26 LONG TERM....17 AVIATION...17  524 FXUS63 KBIS 190324 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 1024 PM CDT Mon May 18 2026 .KEY MESSAGES... - Lows tonight into Tuesday morning dip into the upper 20s to lower 30s. Freeze Warnings and Frost Advisories have been issued. Cold temperatures again possible Tuesday night/Wednesday morning, mainly east. - Isolated showers remain possible overnight west and south central. Patchy fog possible in the far northwest. - Unsettled weather pattern develops mid to end of the week. Greatest and most widespread chances (about 30 to 60 percent) come Thursday into Friday. && .UPDATE... Issued at 1025 PM CDT Mon May 18 2026 Showers have generally exited to the east of western and central North Dakota at the time of this mid evening update. Weak radar returns linger over portions of central North Dakota, though with such poor forcing only sprinkles are anticipated at this time. Otherwise, with clearing skies found upstream to the northwest of the forecast area, did opt to add some patchy fog to northwest for the early to mid morning. UPDATE Issued at 630 PM CDT Mon May 18 2026 Light rain continues across portions of south central North Dakota at the time of this early evening update, with sporadic reports of drizzle also found further to the west. Precpitation is generally expected diminish from west to east through the evening. More isolated showers will be possible across the west and south central overnight, though additional accumulation is would be light. Have tweaked the PoP grids in line with the latest CAM guidance. Will also need to evaluate the potential for additional fog development tonight, especially across the northwest where low stratus is expected to diminish the quickest. Overall, the forecast remains in good shape at this time. && .DISCUSSION... Issued at 223 PM CDT Mon May 18 2026 Current surface analysis places low over the upper midwest with notable frontal boundary stretching to the southwest through the central plains. High remains over southern Saskatchewan into central Montana. Upper level analysis places trough over Saskatchewan southward towards the central Rockies. Southeast flow over our area with some embedded short waves is resulting in broad shower activity over much of South Dakota into southeast/south central North Dakota. For tonight, ongoing showers will continue into this evening before departing to the east/northeast. In the meantime, surface high settles into the area, mainly western locations, with cool air continuing to slide in. This will result in sub freezing temperatures over parts of western and north central North Dakota, therefore a Freeze Warning has been issued. Further east, confidence is a little lower as to how cold it will get given the persistant cloud cover. With that said, lows look to dip close to or reach freezing, so have decided to go with a Frost Advisory for that area even though technically "frost" will not form, but sensitive plants could be damaged, especially if temperatures are a degree or two lower than forecast. Trough pushes east early Tuesday, with a low amplitude ridge passing over for Tuesday into Wednesday. Expect a gradual warm- up for high temperatures, but Tuesday night may see some freezing lows, mainly over our east given the high passing over and clearing skies. Next trough digs in over the western CONUS on Thursday with our flow shifting southwesterly before the system closes off and ejects to the northeast to close out the week. Greatest chances for precipitation come Thursday into Friday (about 30 to 60 percent chance). Warming trend expected going into the weekend with NBM temperature spreads being quite confident in seeing well above average temperatures by late weekend. && .AVIATION/00Z TAFS THROUGH 00Z TUESDAY/... Issued at 1025 PM CDT Mon May 18 2026 Widespread MVFR and sporadic IFR ceilings are found at all terminals as low stratus persists across the region. Rain showers continues across the south central, occasionally promoting the aforementioned IFR ceilings and some MVFR visibility reductions. Ceilings are expected to generally improve through the evening across the far west, with also generally diminishing through this period. Ceilings are then expected to improve across the east overnight through Tuesday morning. North winds will diminish through the evening, becoming light overnight through Tuesday morning as they turn more northwesterly. Gusty winds are then expected to develop in the south central late Tuesday morning through the afternoon, with sustained speeds around 15 knots and gusts up to 25 knots at times. && .BIS WATCHES/WARNINGS/ADVISORIES... Freeze Warning until 9 AM CDT /8 AM MDT/ Tuesday for NDZ001>005-009-010-012-017>020-022-031>033-040-041-043-044- 055>059. Frost Advisory until 9 AM CDT /8 AM MDT/ Tuesday for NDZ013- 023-025-035>037-042-046>048-050-051-060>062. && $$ UPDATE...Adam DISCUSSION...JJS AVIATION...Adam  676 FXUS63 KUNR 190328 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 928 PM MDT Mon May 18 2026 .KEY MESSAGES... - Cold temperatures overnight with freeze/frost headlines - Gradual warmup mid-week with increasing precipitation chances for Thursday/Friday - Sharp warmup for the weekend into early next week && .UPDATE... Issued at 919 PM MDT Mon May 18 2026 Going forecast in pretty good shape. Clouds are starting to breakup as leftover diurnal showers wane per shortwave moving into the upper Midwest. This will allow temperatures to drop into the upper 20s to lower 30s over much of the CWA overnight, covered by Freeze/Frost headlines. A warming trend begins tomorrow and peaks over the weekend. Weak disturbance and a bit of buoyancy may pop weak convection Wednesday with better chances Thursday/Friday as stronger disturbances rotate through the northern Rockies into the northern Plains. Ensemble spreads tight, but then diverge a little for the weekend into early next week, but most paint a sharp warmup in line with flat upper ridge/westerly downslope flow. && .DISCUSSION...(This Evening Through Monday) Issued at 128 PM MDT Mon May 18 2026 Current Water Vapor and upper air models show troughing just east of the Rockies running through the northern and central plains, with upper ridges over the New England region and off the west coast. 19Z surface analysis depicts a surface low to our east over MN, surface high over central MT. Radar shows widespread precipitation across the forecast area, with some of the higher elevations receiving light accumulations of snow today. Winds are currently breezy out of the northwest to north, with temperatures in the 30s to low 40s. Precipitation will taper off from west to east late afternoon through the evening, as trough slides eastward today. Cool temperatures continue tonight as clouds clear up and light northwest winds continue. Much of the area is expected to reach near or below freezing overnight. HREF probability for temps to reach at or below freezing sit at 80-100% for areas from the Black Hills and west. Further east will be a bit trickier as cloud cover will linger into tonight as the trough slowly shifts eastward. A Freeze warning has been issued for most of our plains areas, with a frost advisory in effect for part of south-central SD for Tuesday morning. Brief and weak ridge sets over the region mid-week, resulting in drier conditions and a warming trend towards near seasonable. Another wave rides southeast from western Canada towards the northern plains later in the week, increasing chances for precipitation late Thursday into Friday. Shortwave ridging moves over the weekend, bringing warmer temps back in as well. By Sunday/Monday the region should see highs climb back into the 80s to low 90s. && .AVIATION...(For the 00Z TAFS Through 00Z Tuesday Evening) Issued At 519 PM MDT Mon May 18 2026 An area of precipitation (rain on the plains/snow up high) and low clouds will lift northeast this evening. Widespread MVFR/IFR (local LIFR with the snow) conditions will slowly improve from west to east overnight with lingering MVFR/IFR conditions from KD07-KICR Tuesday morning. VFR conditions are expected all locations after 19/18z. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Freeze Warning until 9 AM MDT Tuesday for SDZ001-002-012>014- 025>027-030>032-041>044-072>078. Frost Advisory until 10 AM CDT Tuesday for SDZ046-047. WY...Freeze Warning until 9 AM MDT Tuesday for WYZ054>056-058>060. && $$ UPDATE...Helgeson DISCUSSION/KEY MESSAGES...Dye AVIATION...Helgeson  678 FXUS64 KOHX 190328 AFDOHX Area Forecast Discussion National Weather Service Nashville TN 1028 PM CDT Mon May 18 2026 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 1023 PM CDT Mon May 18 2026 - Above normal temperatures Tuesday will cool into the low-80s Wednesday into the end of the week. - There are daily medium to high rain chances Tuesday into the weekend. There is only a low severe weather threat Tuesday. - There is a high chance that rain amounts are at least 2 inches by the weekend. && .SHORT TERM... (Tonight through Wednesday Night) Issued at 1023 PM CDT Mon May 18 2026 Satellite imagery this evening shows an upper-level trough over the Great Plains with a cold front over the Kansas/Nebraska area. On Tuesday, this trough will eject into the Great Lakes region with the cold front slowly tracking south through the Ohio Valley. Ahead of this cold front, moisture will be on the rise across Middle TN. There's already evidence of this with dewpoints in the 60s and the PWAT on this evening's sounding rising to 1.14 inches. Do expect this PWAT to continue to rise with models still showing values near to above 1.5 inches. As the aforementioned front approaches, a pattern change is finally here. Scattered showers and storms will mainly favor areas west of I-65 Tuesday afternoon into the evening. While the setup isn't the most favorable for severe weather with highest wind shear displaced to the north, there does remain a low severe weather risk for storms near the front. Main concern would be strong to damaging winds, but forecast soundings do show steep mid-level lapse rates that could result in small hail. The front slowly sags south through Wednesday, and high rain/storm chances will be in place through the day. Don't anticipate severe weather Wednesday with the setup even less favorable with the instability getting pushed south ahead of the front. But it should be a beneficial setup for some much needed rain with the front and PWATs near the 90th percentile for this time of the year. Temperatures will also start to cool behind the front, from upper-80s to low-90s Tuesday into the low-80s Wednesday. && .LONG TERM... (Thursday through next Tuesday) Issued at 1023 PM CDT Mon May 18 2026 The front stalls to our south Thursday, and with a troughing pattern setting up over the eastern CONUS through the end of the week, this will keep medium to high rain chances in the forecast. With the front to the south Thursday, highest rain chances will favor areas south of I-40, but then a series of shortwaves look to bring high rain chances areawide Friday and into the weekend. This is still looking like a very good setup for the rain we do desperately need, and forecast rain totals continue to trend up. By the end of the weekend, probability looks high at 70-80% for widespread rain totals over 2 inches. This pattern will also keep temperatures closer to normal with highs in the low-80s. && .AVIATION... (00Z TAFS) Issued at 528 PM CDT Mon May 18 2026 VFR conditions expected for this TAF cycle, however I have added in a PROB30 for CKV late tomorrow afternoon now that we finally look to have some storms in the area. Time may have to be adjusted slightly with future issuances based on latest guidance. Southerly winds will relax below 10 kts after 00Z, then become gusty again late tomorrow morning with gusts of 20 to 25 kts. && .PRELIMINARY POINT TEMPS/POPS... Nashville 71 91 68 83 / 0 30 60 80 Clarksville 72 90 67 80 / 0 50 70 80 Crossville 66 85 64 81 / 0 10 40 90 Columbia 70 90 67 82 / 10 20 50 90 Cookeville 69 87 66 82 / 0 10 40 90 Jamestown 66 88 64 83 / 0 10 30 90 Lawrenceburg 70 87 67 82 / 10 10 40 90Murfreesboro 71 90 67 84 / 0 20 40 90 Waverly 73 91 67 81 / 0 40 60 80 && .OHX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Clements LONG TERM....Clements AVIATION.....Unger  952 FXUS64 KBMX 190338 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 1038 PM CDT Mon May 18 2026 ...New DISCUSSION... .KEY MESSAGES... Issued at 1036 PM CDT MON MAY 18 2026 - Warm conditions are expected again on Tuesday with highs near 90 degrees. - Chances for showers and storms increase late Tuesday into Wednesday and continue through the weekend, with the highest (40-70%) chances in northern and western portions of Central Alabama during the afternoon and evening hours. - High moisture levels will support periods of heavy rain, though total amounts are anticipated to be light (1-2 inches across the area) && .DISCUSSION... (Tuesday through next Monday) Issued at 1036 PM CDT MON MAY 18 2026 Over the last few hours, we have been watching a few thunderstorms work up the I-65 corridor. A H7 shortwave has been helping guide this activity within a plume of healthy moisture advecting north across the state. These storms are likely to wane over the next hour or two. While chances are low (20-30%), I wouldn't be surprised to see patchy fog develop late tonight, especially in locations that saw rain this afternoon and evening. As we head through the day Tuesday, the upper ridge off to our east will begin to be suppressed as a stout upper trough slides across the Plains. An associated cold front will slowly move towards the southeast, eventually stalling just off to our west. Convection is likely to develop along and ahead of the boundary through the day Tuesday. Latest CAMs continue to hint at this activity decaying before making it into Central Alabama. We will need to monitor trends and any lingering outflow boundaries that may keep this activity going a bit longer and making it into our northwest counties. We will hang onto low to moderate chances for showers and storms daily Wednesday through the end of the week as several shortwaves traverse through the southwesterly flow aloft and interact with the stalled boundary. PWATs will remain elevated through the end of the week, generally in the 1.7-1.9" range which will help support periods of heavy rainfall. Despite the prolonged period of increased rain chances, rainfall amounts are not too impressive, roughly 1-2" across the area. While widespread severe storms are not expected, we could see a few stronger storms develop as we reach peak heating each afternoon. By the weekend, the stalled front retreats back to the north, leaving plentiful moisture in place. Continued bouts of upper level energy will keep moderate rain chances in the forecast. 95/Castillo && .AVIATION... (00Z TAFS) Issued at 617 PM CDT MON MAY 18 2026 VFR conditions prevail through this TAF cycle. The KBMX radar reveals isolated convection, generally across the southern half of the CWA. As a result, I have continued with the PROB30 mention for TSRA at BHM/EET/MGM/TCL through 04Z. Drier air along the AL/GA state line will help keep convection clear of AUO. Winds will be out of the south-southeast from 5-10 knots through this TAF cycle. 95/Castillo && .FIRE WEATHER... Dry conditions are in store for much of the day Tuesday with minRHs in the 40-50% range during the afternoon. Rain chances increase late Tuesday into Wednesday and continue into the weekend as a front stalls near the region, with higher Min RH values. Elevated fire weather concerns are not expected. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 65 88 65 87 / 10 0 0 70 Anniston 65 88 65 87 / 10 10 0 50 Birmingham 70 89 70 87 / 30 0 10 60 Tuscaloosa 69 90 69 88 / 10 0 20 40 Calera 67 90 67 89 / 30 0 10 40 Auburn 67 89 69 89 / 10 0 0 30 Montgomery 68 90 69 89 / 20 0 10 30 Troy 66 90 68 89 / 20 10 1040 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...95/Castillo AVIATION...95/Castillo  056 FXUS63 KDTX 190342 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 1142 PM EDT Mon May 18 2026 .KEY MESSAGES... - Warm and humid conditions exist again Tuesday which supports a risk of severe thunderstorms during the afternoon and evening hours. The strongest storms are capable of damaging wind, large hail, and isolated tornadoes. - A cold front Tuesday night ushers in dry and cooler weather for Wednesday and Thursday. - The next chance of rain arrives Friday and Friday night. && .AVIATION... VFR conditions in place tonight. Strengthening southwesterly winds this morning draws richer low level moisture back into SE MI supporting the developing of scattered low cloud (~2-3kft). There is signal for widely scattered shower development along the nose of this moisture offering a shot at light showers and borderline MVFR cigs for the mid/late morning hours. An approaching cold front reaches southern lower MI by afternoon bringing the next chances for showers/storms. Due to the morning shower/low cloud potential, exactly how much the region is able to destabilize (which in turn will affect the subsequent coverage of thunderstorms) is the main point of uncertainty. As such, have maintained Prob30s groups except for MBS as confidence in convection developing that far to the northwest is lowering, better potential looking towards Detroit. D21/DTW Convection... No convection is forecast tonight through Tuesday morning. There is a chance for scattered storms to develop in the afternoon, ~20-00Z, in advance of a cold front. .DTW THRESHOLD PROBABILITIES... * Low-medium for thunderstorms Tuesday afternoon/evening. * Low for ceilings at or below 5000 ft tonight, medium by Tuesday morning through the day. && .PREV DISCUSSION... Issued at 337 PM EDT Mon May 18 2026 DISCUSSION... Severe Thunderstorm Watch 221 is in effect until 800 pm for the mature MCS inbound into SE Mi. Damaging wind gusts of 70 mph or greater have been reported and remain the primary hazard as the line tracks across SE Mi. Instability trends remain on track as full morning to early afternoon sun lifted temperatures to near 90 all areas. Model MLCAPE up around 2000 J/kg in HREF mean and RAP projections of hourly mesoanalysis add confidence to persistence. The system is already demonstrating benefits of the locally enhanced wind shear profile supplied by the parent MCV resulting in a mature linear convective mode now expected to maintain organization while crossing SE Mi. Storms exit eastward into Ontario by 00Z at or before watch expiration. Another round of severe thunderstorm potential for Tuesday is set up by Midwest low pressure as it moves into upper Michigan while pulling a cold front through the central Great Lakes. SE Mi remains firmly in the warm sector of this system throughout the day with early to mid evening cold front timing offering time for instability to become sufficient. Morning clouds and a stray shower likely slow the pace of surface heating compared to today, however model projections of MLCAPE place 2000 J/kg in reach by 21Z Tuesday afternoon, especially toward the Ohio border. This occurs in a very similar wind profile compared to today in terms of moderate unidirectional shear except with a deeper 40-45 knot layer through 500 mb. Storm initiation timing is the primary uncertainty as shown in the wide range of hi-res model solutions that collectively suggest a later afternoon consensus. Later timing equates to less impact to SE Mi in terms of coverage area and also a more isolated severe threat before storms can better organize while the cold front moves through the area. Frontal passage Tuesday night, before midnight, sweeps storms out of SE Mi and sweeps in cooler air for the mid week period. A broad area of surface high pressure and short wave ridging ensures below normal temperatures but dry weather during this time period as well. Central Plains to Ohio valley low pressure then brings the next round of showers into Lower Mi later Friday and Friday night. MARINE... Attention to the near-term forecast will focus on the ongoing line of thunderstorms that extend across central Michigan. This line will pass across the eastern Great Lakes this evening and will bring heavy downpours, frequent lightning, and strong to severe weather. Strong to severe thunderstorms will be capable of producing wind gusts aoa 50 knots for all of the open water locations. Hail to an inch and/or a waterspout cannot be ruled out but are secondary hazards for severe weather. Prior to this line of thunderstorm arriving, isolated to scattered thunderstorm activity will be possible. A Severe Thunderstorm Watch is in effect until 8 PM EDT. Outside of any thunderstorm activity, breezy southwest to south flow will persist, bringing non-thunderstorm gusts on the order of 20 to 25 knots. The main line of storms will exit late tonight but isolated to scattered showers and thunderstorms will be possible overnight. Renewed strong to severe thunderstorm chances will again be possible tomorrow afternoon and evening which will bring additional chances to see all storm hazards included wind gusts aoa 50 knots. These stronger storms will be most favorable from central Lake Huron and locations south. Outside of thunderstorms, gusts to 25 knots will again be possible during daylight hours. Re-issuance of Small Craft Advisories will be likely. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...Small Craft Advisory from 10 AM to 10 PM EDT Tuesday for LHZ421-422- 441>443. Dense Fog Advisory until 4 PM EDT Tuesday for LHZ361>363-462>464. Lake St Clair...Small Craft Advisory from 10 AM to 10 PM EDT Tuesday for LCZ460. Michigan waters of Lake Erie...Small Craft Advisory from 10 AM to 10 PM EDT Tuesday for LEZ444. && $$ AVIATION.....KDK DISCUSSION...BT MARINE.......BT You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.  250 FXUS63 KJKL 190345 AAA AFDJKL AREA FORECAST DISCUSSION...UPDATED National Weather Service Jackson KY 1145 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 1145 PM EDT MON MAY 18 2026 No significant changes were made to the forecast now that the rogue showers or storms have left the area in the far east. Have mainly updated with 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 SAFs and zones. 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 movesto 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  145 FXUS64 KLUB 190345 AFDLUB Area Forecast Discussion National Weather Service Lubbock TX 1045 PM CDT Mon May 18 2026 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 1042 PM CDT Mon May 18 2026 - Much cooler Tuesday as a cold front passes through during the morning hours with a small chance for an isolated storm across the Rolling Plains. - Cooler and wetter conditions from mid to late week with a chance for heavy rainfall overnight Wednesday. && .SHORT TERM... (Tonight through Tuesday Night) Issued at 1042 PM CDT Mon May 18 2026 Current surface observations late this evening analyze the previously stalled front over the northern Texas Panhandle, where it has resumed its southward progression over the last hour. This FROPA is expected to make it's way into the far southern Texas Panhandle shortly after midnight, around the 06Z to 07Z timeframe. Behind the front, winds will shift out of the north-northeast where they may briefly become breezy around 30 to 40 mph. Additionally, there remains a slim window of opportunity for an isolated thunderstorm to develop along the frontal boundary as it progresses southward through the overnight period. This will be primarily across the far southwestern Texas Panhandle and Rolling Plains, where moisture will be maximized with the dryline slowly retreating westward. However, confidence remains a bit low in regards to precipitaion overnight with models all over the place with timing and location, if any storms at all develop. If they do, convergence along the frontal boundary along with steep mid-level lapse rates around 8 C/km and bulk shear magnitudes around 40 knots would suggest the potential for large hail with any storm that develops. Precipitation chances will wane by daybreak Tuesday, thereafter mostly dry conditions are expected. As the front makes its way through the FA, post-frontal northerly winds will develop and last through much of the morning. Becoming easterly by Tuesday afternoon as a surface low develops over central New Mexico. With the post frontal airmass in place and upslope component to the wind a much cooler day is expected with highs in the 70s expected. Highs will vary across the region, and will remain dependent on the timing of the FROPA. NBM highs seem a bit to warm across our southern zones so opted for a blend of NBM 25th percentile to reflect the FROPA moving through shortly after daybreak. Isolated shower and thunderstorm chances may exists late Tuesday afternoon and evening as the stalled FROPA to our south retreats back north late in the day. Compared to this time yesterday, most guidance has backed off on this scenario. Nonetheless, depending on how far north the boundary retreats will play a factor in the potential for convective initiation. Otherwise, a quiet night is expected for much of the region with cooler overnight temperatures across the far southwestern Texas Panhandle in the mid 40s to mid 50s while off the Caprock expect lows in the 60s thanks to increasing moisture and the potential for low stratus. && .LONG TERM... (Wednesday through next Monday) Issued at 1042 PM CDT Mon May 18 2026 The main theme of the extended forecast package will be the daily afternoon chances for showers and thunderstorms Wednesday through the weekend. Broad large scale troughing will remain established over portions of the western CONUS through the period, while the associated parent trough remains displaced to the north digging into the Canadian Provinces. Embedded perturbations tracking through the main flow out ahead of the base of the trough over the Desert Southwest are expected to translate through the region each day from mid to late week this week. Meanwhile off to our east, an upper level ridge will remain overspreadmuch of the southeastern CONUS. This synoptic setup will support southwest flow aloft initially, before we see a more westerly regime set-up by late Wednesday in response to the upper low digging south into portions of the Intermountain West. This more zonal flow aloft will likely limit subtropical moisture transport into the region, with recent guidance placing the bulk of the moisture plume east of the area. This is also reflected in both the GEFS and ECMWF ensemble runs with the QPF footprint favoring higher precipitation totals off to our east. Nonetheless, the upslope component to the surface winds with relatively easterly flow will work to transport moisture in from the Gulf allowing for rich low-level moisture to advect into the region. Dewpoints are progged in the 50s and 60s, with mid to upper 60 dewpoints positioned across the southeastern Rolling Plains where we expect the best moisture to be positioned. Similar to the m-d to upper level moisture, the better forcing for ascent looks to remain confined to a pair of H5 jet maximas that are forecasted to remain north and south of the region. Therefore, precipitation chances across the area will be dependent on the perturbations translating through the main flow and interacting with the moisture already in place. Ensembles continue to hint at the best opportunity for shower and thunderstorm activity being late Wednesday into Thursday morning, when the strongest vorticity max moves through the northern Texas Panhandle and West Texas region and taps into the plentiful moisture. If showers and thunderstorms are able to develop, there is a chance for heavy rainfall across portions of the region, primarily our southern counties, where we find PWATs around 1.25" to 1.50" which is well above the 90th percentile seasonal normal for this time of year. This will likely be the main severe threat with activity, although small hail cannot be ruled out given modest MLLR around 7 to 8 C/km and MUCAPE values around 1500-1700J/kg. Expect a similar set up each afternoon Thursday through Saturday as perturbations track through the region and attempt to tap in to the moisture in place across the region. As for temperatures, Tuesday's cold front will provide the much needed relief from the absurdly warm temperatures we saw last week and this past weekend. Easterly winds will remain in place as well through much of the week and with little to no change in heights and thickness values we can expect highs in the 70s to hold through at least Friday, before we begin to see a subtle warm up back in the 80s through the weekend. && .AVIATION... (00Z TAFS) Issued at 632 PM CDT Mon May 18 2026 VFR and strong south-southwesterly surface flow will continue through the rest of this evening, with winds then gradually weakening after sunset. A cold front will pass southward through the region tonight, and will bring a shift to strong north winds which will continue from before sunrise on Tuesday through the rest of the morning. Some convective development is expected along the front, with TS possible overnight especially at KCDS with lesser chances for thunder at KLBB and KPVW. A period of post- frontal MVFR CIGs is also possible at all sites on Tuesday morning, with highest confidence in MVFR CIGs at KCDS. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...12 LONG TERM....12 AVIATION...30  377 FXUS64 KMEG 190348 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1048 PM CDT Mon May 18 2026 ...New DISCUSSION, AVIATION, FIRE WEATHER... .KEY MESSAGES... Issued at 1048 PM CDT Mon May 18 2026 - Hot and humid conditions are expected through Tuesday, with high temperatures reaching or exceeding 90 degrees in many locations. - Widespread showers and thunderstorms will return to the forecast by Tuesday afternoon, bringing a slight (level 2 out of 5) risk for damaging wind gusts. - Chances for showers and thunderstorms will persist daily beginning Tuesday through the remainder of the upcoming week. && .DISCUSSION... (Tonight through next Monday) Issued at 1048 PM CDT Mon May 18 2026 Upper air observations continue to show a large upper ridge axis centered over the Atlantic coastline with a trough ejecting into the central Plains. At the surface, a cold front currently extends southwest from the Midwest into the southern Plains with a broad area of southwesterly flow extending into the Midsouth. The combination of southerlies and upper ridging has allowed for temperatures to eclipse 90 F Monday. Convection and the strengthening of a surface high over the northern CONUS will kick the front eastward through Tuesday. Temperatures are expected to have time to reach back into the upper 80s and low 90s again before the front arrives, which is progged to occur through Tuesday afternoon. Thunderstorms are expected to accompany the front as it moves into the region. Plenty of MLCAPE (2500 - 3000 J/kg) will be in place by early afternoon just ahead of the boundary. However, the upper trough in the plains will have ejected into Canada by this point, leaving only paltry upper level winds and forcing with less than 25 kts. So, storms may struggle to organize, especially ahead of the front. A branch of the subtropical jet will impinge on the region from the southwest, but the stronger winds are expected to remain above 500 mb, leaving little to no impact on the effective shear. Regardless, current HRRR guidance does display ~900 J/kg DCAPE, supporting a marginal/slight threat for damaging wind gusts with any thunderstorms. The hail threat will be muted due to the weak shear and sub-optimal mid-level lapse rates with little to no expectation for tornadoes given near-zero SRH. Any troughing will decrease in amplitude throughout the southeastern CONUS quickly into Wednesday. The front will then stall somewhere within the region, washing out as upper ridging returns. Temperatures will drop in response to cloud cover and rainfall, bringing highs into the upper 70s and low 80s through the end of the work week. However, the front will not have made a significant dent on the abundance of moisture that has plagued us since last weekend, keeping elevated rainfall and thunderstorm chances in the forecast into next week. Looking at LREF guidance, there is enough agreement regarding QPF that the probability of 3"+ of rainfall exceeds 50% throughout the majority of the region. Severe weather chances are still uncertain as the upper pattern remains at a low-amplitude, but models (NAM/GFS/ECMWF) gradually increase large-scale troughing with a few, smaller waves embedded in the flow. If these features are able to remain in the forecast come Wednesday through Friday, low-end severe chances could materialize with higher effective shear. In summary, a cooler, rainier forecast is expected through at least next weekend with the potential for some severe weather depending on how the upper pattern shakes out. && .AVIATION... (06Z TAFS) Issued at 1048 PM CDT Mon May 18 2026 Prevailing VFR conditions are expected through at least the middle of the day tomorrow, before SHRA/TSRA moves across the airspace along a frontal boundary. There is still fairly low confidence with the timing aspect of things, so have left any TSRA mention in PROB30 grouping for all four terminals generally in the afternoon and early evening. Some lingering -SHRA behind temp vis/cig drops with TSRA cannot be ruled out, but terminals should quickly rebound back to VFR. Otherwise, southerly winds will become gusty once again around 14 to 15Z, with gusts upwards of 20 to 25 kts for MEM, MKL, and JBR. Winds will fall back below 7 kts by 00Z, with some variability into the end of the current TAF period. && .FIRE WEATHER... Issued at 1048 PM CDT Mon May 18 2026 No major fire danger concerns for the foreseeable future, with minimum relative humidity values remaining above 40%. Wetting rains will return beginning Tuesday, lasting through at least the end of the week with the potential for thunderstorms each afternoon. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...JAB AVIATION...CMA  438 FXUS63 KOAX 190350 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 1050 PM CDT Mon May 18 2026 .KEY MESSAGES... - Cooler weather moves in on Tuesday with potential for morning frost for northeast Nebraska on Wednesday. - Shower/thunderstorm chances return Wednesday night into Thursday continuing on/off through Friday. - Trend back toward warmer temperatures over the weekend. && .DISCUSSION... Issued at 1050 PM CDT Mon May 18 2026 Severe weather has cleared to the southeast this evening leaving cool, cloudy conditions in place for the overnight hours. We have a large temperature gradient across the area with temperatures in the upper 40s across northeast Nebraska, to low-to-mid 60s in southwest Iowa and far southeast Nebraska. The HRRR continues to show some potential for a couple additional storms developing over far southeast Nebraska and southwest Iowa around midnight tonight. If anything were to develop, it likely wouldn't be severe. Skies will be clearing Tuesday morning as high pressure builds over the area. Cooler air mass remains in place under northerly flow. Overnight Tuesday night into early Wednesday we light winds and clear skies contribute to temperatures dropping into the low-to-mid 30s across northeast Nebraska, possibly necessitating a frost advisory for this area. Places more across southeast Nebraska and southwest Iowa will see temperatures drop into the upper 30s to low 40s, though a few outlying areas around Omaha and Lincoln could still see some patchy frost. High pressure remains centered over the region on Wednesday keeping temperatures cooler than normal with highs in the upper 50s to low 60s. The trough over the northern Rockies starts to deepen on Wednesday, re-amplifying southwesterly flow across our region. This will bring moisture back to our area with increasing clouds into the afternoon. Rain chances return late Wednesday into Thursday as the trough over the northern Rockies starts to deepen, reamplifying southwesterly flow across our region which will lead back to moisture advecting back into our area from the Gulf. As a warm front lifts into northern Kansas on Wednesday, we see isentropic upglide over our area lead to shower and storm development starting Wednesday night continuing into Thursday. We don't actually see the warm front lift into our area until Friday, keeping temperatures cool on Thursday as well. Friday the warm front lifts north, getting wrapped up into a developing surface low over the Northern Plains. This will reinvigorating shower and storm chances through the morning hours. We may see a small window of clearing before the cold front arrives Friday afternoon/evening. We should watch this period with some potential for severe storms, but at this time there is still a lot of uncertainty surrounding the details of this system. Confidence significantly decreases in the forecast going into next weekend as significant differences in the forecast of the upper-level pattern develop. Ensembles suggest a trend back toward warmer-than-normal temperatures toward the latter-half of the weekend with low chances for storms possible Saturday and Sunday. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1244 PM CDT Mon May 18 2026 Widespread IFR/MVFR ceilings are observed across terminals this afternoon. Will see an area of scattered showers and storms overspread KLNK and KOMA after 21z. Have refined timing a bit with this issuance, but expect further refinements and adjustments. Storms that affect terminals will likely become severe with strong winds, very large hail, and the potential for a tornado. Have added a transition to -SHRA at KOMA and KLNK after 01/02z. Ceilings will bounce between MVFR/IFR overnight, before largely becoming MVFR late in the TAF period. Winds from the north northeast will turn to the north northwest this evening, with gusts gradually increasing to 25 to 30 kts, persisting for the rest of the TAF cycle. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...McCoy AVIATION...Castillo  533 FXUS63 KAPX 190354 AFDAPX Area Forecast Discussion National Weather Service Gaylord MI 1154 PM EDT Mon May 18 2026 .KEY MESSAGES... - Marginal risk for severe thunderstorms on Tuesday. - Sharply cooler weather arrives Wednesday and Thursday, with frost/freeze concerns Tuesday night through Thursday night (especially on Wednesday night). && .DISCUSSION... Issued at 1207 PM EDT Mon May 18 2026 Pattern Synopsis/Forecast: Moisture rich warm sector spreading northeast across the Great Lakes this afternoon as deep layer southwest flow continues between southeast Conus ridging and deep troughing rotating across the Intermountain West. Showers and thunderstorms beginning to percolate across northern Lake Michigan along decaying cold pool convergence (from overnight convection to our west). Surface based warming and attendant northward expansion of over 500 joules/kg of mixed layer cape within marginally supportive convective layer shear should continue to allow intensification of this activity as it races east across our area. Deep upstream troughing will continue to lift northeast, steadily shearing out as it crosses into southern Canada and the northern Great Lakes later Tuesday into Tuesday night. Attendant cold front expected to cross our area on Tuesday, with additional showers and storms expected to fire in the pre-frontal warm sector until its crossing. Sharply cooler airmass follows this passing wave, setting the stage for additional frost/freeze concerns for the middle of the week. Primary Forecast Concerns: Shower/storm evolution and severe potential through Tuesday. Secondary focus on just how cold we become through the middle of the week (those frost/freeze concerns). Details: Expect upscale growth to convective activity as it quickly slides northeast across our area the remainder of this afternoon. Combination of instability, those marginal convective layer shear profiles, and expected congealing cold pool dynamics should support some isolated severe potential, with gusty winds and marginally severe size hail the primary concerns. However, slightly backed low level wind fields down near Saginaw Bay will also support a very low risk for tornadoes as well. Loss of surface based instability should end the most aggressive shower/storm concerns quicky early this evening. Focus for most numerous storms and greatest severe potential focuses off to our west tonight in vicinity of primary wave and attendant east advancing cold front. May see some of this decaying activity slide into our area later tonight/early Tuesday morning. Not expecting anything too significant with this activity as surface rooted instability core is lost by then. Cold front will work steadily east across our area on Tuesday...exiting off to our east by early Tuesday evening. Front becomes increasingly detached from any large scale support, though moisture rich pre-frontal environment and forced low level convergence will continue to support shower and storm generation. Severe potential tied to just how much heating/surface rooted instability generation can occur prior to frontal passage. Think ongoing showers and cloud cover may limit this potential, with focus for severe storms centering to our south and southeast. SPC maintains just marginal severe weather potential across northern lower Michigan...themselves focusing on pre-frontal destabilization concerns. Focus quickly shifts to the arrival of a much cooler airmass as Canada originated high pressure drops into the western Great Lakes Tuesday night into Wednesday. Simple breadth of cold air advection looks to drop temperatures down into the 30s across a good portion of the area Tuesday night, although maintenance of gusty northwest winds will likely prevent much freeze or frost concerns. A chilly Wednesday...when some areas will likely not get out of the 40s...gives way to what is shaping up to be a cold Wednesday night. Pattern recognition definitely supports such, with high pressure centering directly overhead supplying what should be clear skies and light/calm winds...all within an already exceptionally chilly airmass. Widespread lows well down into the lower and middle 30s looks easily attainable, and fully believe some of our traditional colder interior areas will make a run into the 20s. Definitely something to monitor given our recent warm temperatures. Conditions modify some Thursday and Thursday night, but could still see more frost and potential freeze concerns early Friday morning. Current trends support slow moderation through the weekend, with readings at least approaching more normal levels on Sunday. Other than the chill, extended period looks far less active, with perhaps some better rain chances returning during the weekend. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 1154 PM EDT Mon May 18 2026 Fog/stratus is developing, especially in northern sites (CIU/PLN/APN). IFR to VLIFR expected at times overnight. This should improve as thicker clouds and showers return to the area toward and after daybreak. Still expect CIU to be IFR/LIFR for much of Tuesday, and PLN for Tuesday morning. MVFR elsewhere Tuesday with some showers, and perhaps a few TSRA. Breezy s to sw winds early Tuesday become w and nw late. && .APX WATCHES/WARNINGS/ADVISORIES... MI...None. MARINE...Small Craft Advisory from 8 AM Tuesday to midnight EDT Tuesday night for LHZ345>349. Small Craft Advisory until midnight EDT Tuesday night for LMZ323-341-342-344>346. Small Craft Advisory from 8 AM Tuesday to midnight EDT Tuesday night for LSZ321-322. && $$ DISCUSSION...MSB AVIATION...JZ  634 FXUS64 KOUN 190357 AFDOUN Area Forecast Discussion National Weather Service Norman OK 1057 PM CDT Mon May 18 2026 ...New AVIATION... .KEY MESSAGES... Updated at 1046 PM CDT Mon May 18 2026 - There is a risk for strong to severe thunderstorms this afternoon through Tuesday. - Critical fire weather conditions are possible for far western Oklahoma into western north Texas this afternoon - Very warm temperatures are expected today with cooler weather by Tuesday. && .NEAR TERM... (Rest of today and tonight) Issued at 126 PM CDT Mon May 18 2026 Windy with potential fire weather across our far west and severe risks for storms are the headlines for today and tonight's period. The strong low-level jet overnight is not expected to weaken too much today as we could see wind gusts in the 40-50 mph as we continue to mix higher into the jet. A deepening surface low lee of the Colorado Rockies will maintain a tight pressure gradient across our area with south winds sustained at 20-25 mph. As a result our current Wind Advisory will remain in effect through this evening in areas generally west and north of the I-44 corridor. A dryline approaching our western CWA is expected to advance across the western one-tier of our counties in Oklahoma and adjacent northern Texas. As a result the fire danger potential will be increasing Near Critical to Critical risk west of the dryline due to very low afternoon RH's expected along with the gusty south winds and hot temperatures over still dry vegetation. A Red Flag Warning will be in effect this afternoon into the evening hours in that one-tier of counties west of the dryline. As far as storms, there is a 20-25% probability for convection firing up along and east of the dryline as forecast soundings suggest diurnal heating eroding the mid-level cap. Should any storms initiate they would be growing in strongly unstable (3000- 5000 J/kg) environment. Although deep-layer shear may be weak this afternoon in our area but expected to increase tonight along with the low-level shear as the low-level jet strengthens. Although the overall highest severe risk will be highest across the Central Plains the risk will extend into the Southern Plains with an Enhanced risk across northern Oklahoma to a Slight risk covering all but our far southeast CWA. Should any dryline convection initiate there is a potential for supercells producing large hail and damaging wind gusts and a conditional risk for a tornado with that risk highest closer to the Central Plains in northern Oklahoma. Storm POPs increase late tonight up to 80% with a cold front coming down the Central Plains advancing into northern Oklahoma late this evening pushing across the remainder of our forecast area through the early morning hours. Todays severe risks and associated hazards will be remain unchanged for tonight in the warm sector along and ahead of the cold front as the shear will be increasing. && .SHORT TERM... (Tuesday through Wednesday night) Issued at 126 PM CDT Mon May 18 2026 By sunrise Tuesday expecting the cold front & storm activity to be near the I-44 corridor and continue pushing south and east. Storm POPs will remain high up 60-90% along the front during the remaining morning hours but more restricted to southeast Oklahoma in the afternoon with the cold front eventually exiting our area. The severe risk remains along the cold front into Tuesday afternoon with the hail & wind hazards remaining although the tornado risk will be very low. High surface pressure starts building in behind the cold front with lighter north winds advecting much cooler air down through the Great Plains. Although the coolest air may lag reaching southeast Oklahoma and our Texas counties for a day, the remainder of our areawill see milder unseasonably cooler temperatures with highs near 70 degrees with the muggy air restricted to southeast Oklahoma. Although our area will be post-frontal by Tuesday evening, the main systems upper trough will remain opened across the western U.S. through this week with a series of short-wave disturbances expelled downstream over the Southern Plains each day producing elevated-based convection. The first of these disturbance will increase storm chances Tuesday evening and overnight across our area. Although the ECMWF is less aggressive with the elevated instability, the NAM suggests these elevated storms could produce severe hail & winds overnight. For Wednesday all of our area will feel milder with highs in the lower to mid 70s becoming chilly with overnight lows in the 50s to low 60s and storm chances again increasing overnight. && .LONG TERM... (Thursday through Sunday) Issued at 315 AM CDT Mon May 18 2026 An active subtropical jet stream (STJ) with subtle waves lifting into the Southern Plains will result in a daily chance of showers/storms through the end the week into next weekend. At this time, there is no day that has an appreciable risk for severe weather. Temperatures are expected to be seasonable for late May. Mahale && .AVIATION... (06Z TAFS) Issued at 1046 PM CDT Mon May 18 2026 A cold front will continue to move through the area tonight and into tomorrow, causing the winds to shift to the north-northeast in its wake. Thunderstorms are expected along this boundary as it moves towards the south. MVFR conditions will persist behind front through the end of the period. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 86 61 70 55 / 20 60 40 60 Hobart OK 93 60 72 54 / 20 60 20 50 Wichita Falls TX 92 68 81 58 / 30 20 80 70 Gage OK 96 49 72 46 / 20 20 0 10 Ponca City OK 89 58 69 52 / 20 80 20 30 Durant OK 88 74 84 64 / 20 10 90 60 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...Wind Advisory until 3 AM CDT Tuesday for OKZ004>027-034>038. TX...None. && $$ NEAR TERM...68 SHORT TERM...68 LONG TERM....10 AVIATION...13  637 FXUS65 KPIH 190357 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 957 PM MDT Mon May 18 2026 .KEY MESSAGES... - A very chilly overnight tonight in the Snake River plain and eastern Magic Valley. Frost and Freeze bulletins have been issued. - Some precipitation, including Thursday afternoon thunderstorms, is possible starting Tue evening and continuing through Thu afternoon. - Weaker wind until the weekend. && .DISCUSSION... Issued at 143 PM MDT Mon May 18 2026 Tonight through Thu afternoon...Save for some showers in the extreme southeast corner of the forecast area, the next 24 hours will continue to be dry, cool to cold, and windy. This is due to an upper level trough currently in WY still pushing slowly eastward. The clear skies and continued northerly airflow means a quite cold overnight tonight, with 20 to 30 degrees expected in the Snake River plain. With the northerly flow not as strong in the eastern Magic Valley, temperatures are only expected to bottom out tonight in the middle 30s. These two reasons are why a Frost Advisory has been issued for the two Magic Valley zones and a Freeze Warning once again for all zones in the Snake River plain. The start time was mostly based on when the affected zones finally lose this strong wind tonight, which is still actually fairly late. By 19/15Z 19/0900MDT the temperatures should surge back above Freeze and Frost thresholds. The north wind is expected to shift to a southwest wind and not be as problematic for the Snake River plain for Tue. The light northerly wind in the morning will shift to a south to southwest wind for the afternoon, ending the need for a Lake Wind Advisory on Tue. This lighter south to west wind continues Wed, then a northerly wind returns for Thu. It doesn't take much for a Lake Wind Advisory to be needed in the north flow regime, so it may return. Finally, impulses moving through the northwest to west upper air flow will return on Tue night. This will mean showers over the north end of the forecast area that night, then a further digging southward will spread precipitation from a close low in central MT for heavier rainfall on Wed night and Thu morning. The precipitation will be mainly focused on the central Idaho mountains and the southern and eastern highlands, with the northern end of the Snake River plain most likely to see precipitation in the lower elevations. While isolated thunderstorms are possible Tue and Wed, Thu includes the associated cold front with this MT low actually coming through and generating high chance of thunderstorms. Since the afternoon has more unstable air, the best threat is in the eastern third of the forecast area. Thu night through next Mon...The low clears out early enough on Thu that while it is colder, the sunny skies of Fri should allow a warming trend to develop quickly. By Sat afternoon temperatures should soar above normal after a near normal Fri afternoon. A gradual warming trend continues at least into Mon, for both highs and lows. Weak troughing gets replaced by weak upper level ridging, which will allow some breezy westerly wind, but doesn't appear to bring an significant precipitation. It appears to be fairly limited to higher elevations that can provide lifting with west-facing slopes in the zonal flow, especially Fri and Sat. Only a minority of the solutions cluster around a wet scenario for eastern Idaho. This accounts for the warming trend. The zonal flow tightens starting Sat, so it will likely be breezy to windy for Sat/Sun/Mon, at least in the afternoon. && .AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/... Issued at 957 PM MDT Mon May 18 2026 Winds look light through tomorrow. Some mid cloud around SUN, BYI and PIH should dissipate overnight. SUN will probably switch to upvalley around midday, think a crosswind is unlikely in the afternoon with winds as light as they are. && .PIH WATCHES/WARNINGS/ADVISORIES... Frost Advisory from 3 AM to 9 AM MDT Tuesday for IDZ051-055. Freeze Warning until 9 AM MDT Tuesday for IDZ052>054. && $$ DISCUSSION...Messick AVIATION...13