804 FXUS63 KBIS 181508 AFDBIS Area Forecast Discussion National Weather Service Bismarck ND 1008 AM CDT Mon May 18 2026 .KEY MESSAGES... - Medium to high chances (40 to 80 percent) for showers this afternoon through this evening south central and into the James River Valley, low chances elsewhere. - Cold overnight low temperatures near or slightly below freezing tonight (west and north central), and Tuesday night (southwest, central, and east). - Temperatures warming back to above normal by late in the work week and for the weekend, with near daily chances for showers and a few thunderstorms. && .UPDATE... Issued at 930 AM CDT Mon May 18 2026 Fog over the area has mainly dissipated as visibility has improved. Otherwise, going forecast remains on track with rain showers over South Dakota continuing to lift northeasterly. UPDATE Issued at 645 AM CDT Mon May 18 2026 Webcams and observations showing some dense fog across north western and north central North Dakota this morning. This fog should diminish by mid to late morning, however have issued an SPS for its potential impacts on the morning commute. Otherwise low clouds remain across the area. Shower activity has diminished, although some pockets of drizzle are still possible. The next round of rain is starting to take shape in western South Dakota. Left PoPs as is as we continue to monitor the progression of this next round. Lastly SPC does have southeastern North Dakota in a general risk for thunderstorms today. The better instability is in South Dakota and further south today. Perhaps some lightning is possible this afternoon with heavier showers, however, the overall threat for thunderstorms today is very low. && .DISCUSSION... Issued at 357 AM CDT Mon May 18 2026 Upper level trough will push across the state later today bringing the next round of showers. Before doing so, lingering low level moisture will bring abundant cloud cover and cooler temperatures this morning through today. A few rain showers and pockets of drizzle will also be found this morning, along with some patchy fog, as a result of this lingering low level moisture. An increased gradient on the surface of the exiting surface low may also bring some breezy north winds today to southern and eastern portions. Temperatures today will be quite cool and generally in the 40s, with some lower 50s. Later today through this evening, the mentioned upper level wave will move through bringing more organized showers to the state. Best chances for these showers remain across south central and eastern portions of the state where the better synoptic lift is. Isolated to perhaps scattered showers are possible elsewhere. QPF will be much less from this second wave, with the higher amounts being a tenth to a quarter of an inch in the southeast. The mentioned wave moves eastward tonight, although a few showers may linger as it does so especially in the west. Perhaps a rain snow mix is possible from these lingering showers. Cooler temperatures will also be found tonight with lows in the 30s. Depending if clouds can clear, some frost is possible. Low level moisture looks to linger, although some far western portions could at least partially clear which may be the area to monitor tonight for frost. Although not in the forecast, perhaps some patchy fog is also possible tonight into Tuesday morning with light winds and lingering low level moisture. Surface high will push this low level moisture eastward on Tuesday. Some isolated showers are possible in the morning as it does so, then look for clearing skies and slightly warmer temperatures in the 50s. Breezy northwest winds could also linger in the east for Tuesday. This surface high combined with ridging aloft will bring clearing skies tonight and colder temperatures. Most areas are forecast in the 30s, with some areas in the central and east could see temperatures near to slightly below freezing. Widespread frost is still likely, with perhaps some freeze highlights also needed. There still remains some uncertainty if we fully clear out and if a switch to a breezy southerly flow occurs overnight. Will continue to message the cold temperatures, yet hold off on any highlights at this time for Tuesday night into Wednesday morning. A breezy southerly flow is then forecast for Wednesday, with another broad trough pattern approaching the state. Warmer temperatures will return as a result with highs forecast in the 70s. Some lower RH values may also return, although recent rainfall should help with fuels. This trough pattern could also bring some isolated to scattered showers and thunderstorms in the afternoon and evening for Wednesday. Broad trough pattern then looks to continue through the end of the upcoming week. This is forecast to bring seasonable temperatures and near daily chances for showers and thunderstorms. Instability looks limited during the work week, thus the chances for severe thunderstorms looks low at this time. Daily high temperatures in the 60s with lows in the upper 30s to mid 40s are also expected, limiting the frost and freeze threat for the end of the week. Warmer temperatures are then possible for the upcoming weekend with highs in the 70s Saturday to perhaps near 80 on Sunday. Current NBM chances for precipitation this coming weekend are low, although zonal flow aloft and some weak instability could change this with each forecast update. These warming temperatures could also bring lower RH values in the afternoon this weekend. Winds generally look light, which should limit the fire weather threat. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 645 AM CDT Mon May 18 2026 Low clouds will continue through much of the day today, bringing MVFR to periods of IFR ceilings. Some areas of fog are also being report across northwestern and north central portions this morning bringing LIFR conditions. Fog could last through the mid to late morning hours, and generally from KXWA to KMOT. The next round of showers is expected to return this afternoon through this evening, and will be more confined to the south and east, although most sites will have at least slight chances for rain showers. Any shower has the potential to bring MVFR to IFR conditions. Tonight will see shower activity diminish, although low clouds could linger bringing MVFR to isolated IFR ceilings. Some low VFR ceilings may be found for western sites late tonight into early Tuesday morning. Patchy fog may also return tonight, although confidence is not high enough to include at this time. A breezy north wind may also be found throughout much of the forecast period. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...JJS DISCUSSION...Anglin AVIATION...Anglin  130 FXUS63 KILX 181511 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 1011 AM CDT Mon May 18 2026 .KEY MESSAGES... - There is a Slight Risk (level 2 of 5) for severe weather areawide today. While all severe weather hazards will be possible, damaging wind gusts in excess of 60 mph will be the most likely. - Additional thunderstorms will develop along an advancing cold front on Tuesday, with a Slight Risk (level 2 of 5) for severe weather in areas east of Interstate 55. Once again, damaging wind gusts in excess of 60 mph will be the most likely hazard. && .UPDATE... Issued at 1010 AM CDT Mon May 18 2026 A remnant MCS is working across central IL late this morning, producing sporadic reports of wind damage and heavy rain. Isolated storm cells out ahead of the main line in east-central and southeast IL are lifting through a less worked over environment characterized by MLCAPE and DCAPE over 1000 J/kg. Although weaker wind shear coincides with the isolated cells, increasing shear and dewpoints from late morning into early afternoon could support a continued damaging wind and isolated large hail threat. A Severe Thunderstorm Watch has been issued in coordination with SPC through this afternoon. && .DISCUSSION... Issued at 543 AM CDT Mon May 18 2026 Active Convective Complex This Morning... Radar analysis early this morning reveals a robust linear Mesoscale Convective System (MCS) stretching from north-central Wisconsin down through southeast Iowa, central Missouri, and into eastern Kansas. Strong, consolidating cold pools have allowed a leading outflow boundary to outrun the primary convective line. Convective-allowing models (CAMs) exhibit high confidence that this system will maintain its structural integrity as it pushes eastward into the central Illinois forecast area later this morning. Sustaining this morning activity is a potent 40-50 kt low-level jet (LLJ) parked directly over central Illinois. This feature, working in tandem with subtle mid-level shortwaves embedded within the southwest flow aloft, is providing ample synoptic lift and elevated instability (MUCAPE around 1500 J/kg). While weak deep- layer shear (> 30 kts) should keep the morning activity largely disorganized and sub-severe, mid-level dry air and localized evaporative cooling could help overcome the waning morning inversion, supporting isolated severe hail or localized downburst winds. As an interesting aside, numerous runs of the HRRR overnight depicted an area of 40-50 kt surface winds within the trailing stratiform region, in an otherwise unassuming area. While it is uncertain if the model is resolving a wake-low or meso-high feature, the trend bears close observation. If these winds materialize, a short- fused wind advisory or high wind warning may become necessary for a brief window this afternoon. Severe Potential This Afternoon... By early afternoon, attention shifts to areas near and east of a Taylorville-to- Champaign line. A compact shortwave trough is progged to lift northeastward out of southeast Missouri around 18z, enhancing background kinematic shear and dynamic forcing across a highly buoyant boundary layer. In this zone, temperatures climbing toward the 80-degree mark and dewpoints hovering near 70 degrees will yield SBCAPE values exceeding 2000 J/kg. While the incoming shortwave will likely spark an increase in convective coverage ahead of the main morning line, individual storm intensity remains somewhat conditional. An important limiting factor is that mid-level lapse rates will likely deteriorate through the afternoon as the residual Elevated Mixed Layer (EML) exits to the east. However, as deep- layer shear ticks upward across southeast Illinois later today, localized enhancements within the main convective line remain a possibility. This could yield bowing segments capable of producing the full spectrum of severe weather hazards as the line advances into the southeastern counties. The severe threat will not completely diminish after dark. Additional shortwaves interacting with the persistent 40-50 kt LLJ core will likely sustain elevated convective development ahead of the approaching cold front well into Tuesday morning. Conditional Severe Threat on Tuesday... Significant forecasting uncertainty shrouds the Tuesday period, primarily driven by nebulous synoptic forcing and the likelihood of extensive morning convective debris. If widespread cloud cover and rain persist deep into the morning hours, afternoon destabilization will be severely limited, rendering the severe weather threat highly conditional. At this juncture, the highest probability for boundary layer recovery exists near and south of the Interstate 72 corridor, extending through southeast Illinois ahead of the advancing cold front. Should adequate destabilization manifest, favorable instability and deep-layer shear profiles would initially support discrete supercellular structures. However, because the regional shear vectors are oriented nearly parallel to the surface frontal boundary, any discrete activity is expected to transition rapidly into a linear MCS as the front sweeps through Tuesday evening. Hydrological Concerns and High QPF Variability... Confidence remains exceptionally high that multiple rounds of convective rainfall will impact the entire region through Tuesday evening. However, the complex, repeated nature of this pattern introduces severe spatial discrepancies in expected precipitation totals. 48-hour HREF Localized Probability Match Mean (LPMM) QPF projections valid through 00z Wednesday demonstrate a stark variance, showing localized pockets picking up a mere quarter-inch while repeating Storm cores could exceed 4.5 inches. Current model guidance continues to pinpoint the highest risk for these excessive, flood-producing rainfall totals along and south of the I-72 corridor, where repeated convective elements are most likely to anchor. Midweek Clearing Followed by a Wet Weekend Outlook... Wednesday through Thursday: A welcome pattern shift occurs mid- week as a cooler, significantly more stable post-frontal regime takes hold. Continental high pressure building into the Midwest will clear skies and lower humidity levels, offering a brief reprieve from the active weather. Friday through Sunday: The dry spell will be short-lived. Global deterministic models are in notably better agreement, signaling a return to a wetter, unsettled pattern by late week. As the surface high pressure slants eastward, a potent mid-level shortwave will advance across the central U.S. A steady plume of Gulf moisture combined with a series of minor shortwave impulses lifting northeast from the Southern Plains will keep central Illinois susceptible to multiple rounds of scattered showers. While weak kinematic profiles should heavily restrict the overall severe weather risk, a gradual build-up of instability over the weekend will support widespread thunderstorm development. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 519 AM CDT Mon May 18 2026 A line of thunderstorms approaching from the west is expected to reach KPIA by 13Z, KSPI and KBMI by 15Z, and KDEC/KCMI by 16Z this morning. A three-hour TEMPO group has been included to account for IFR visibilities during the storms, with scattered showers likely to linger for several hours afterward under generally VFR conditions. Brief periods of degraded conditions are possible within the most intense storm cells. South winds areforecast to increase to 15-20 kts this morning, with gusts reaching 25-30 kts. Low-level wind shear is anticipated late tonight at regional terminals as 50 kt southwest winds return aloft. An additional round of thunderstorms will move in from the west overnight before sunrise; a PROB30 group has been added to address this potential. && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$ KEY MESSAGES...NMA/MJA UPDATE...NMA DISCUSSION...MJA AVIATION...MJA  930 FXUS64 KHUN 181531 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 1031 AM CDT Mon May 18 2026 ...New NEAR TERM, SHORT TERM... .KEY MESSAGES... Updated at 1030 AM CDT Mon May 18 2026 - Low chances (10%-20%) for showers across northeast Alabama today. - Low to medium chances (20-60%) for showers and thunderstorms returning late Tuesday, then medium to high chances (50-90%) for showers and thunderstorms each day, from Wednesday through the weekend && .NEAR TERM... (Rest of Today and Tonight) Issued at 1030 AM CDT Mon May 18 2026 Morning satellite imagery indicating mostly clear skies with scattered low/mid cloud cover passing through the Tennessee Valley. Temps are already pushing 80 degrees this morning with dew points in the mid/upper 60s. Highs will top out in the upper 80s to right around 90 degrees once again this afternoon with southerly winds of 10-15 mph gusting near 20 mph. Axis of slightly better moisture and instability (SBCAPE ~1000 J/kg) will remain east of I-65 this afternoon where there will be a 10-20 percent chance primarily for shower activity. A rumble of thunder is not out of the question but should be few and far between. Tonight...winds will drop off after sunset with lows remaining mild in the mid to upper 60s. && .SHORT TERM... (Tuesday through Thursday) Issued at 1030 AM CDT Mon May 18 2026 Mid-level ridge which has been in place to our east for several days will begin to weaken over the local area on Tuesday as a trough swings across the northern Plains and associated sfc low transitions northeastward across the Great Lakes region. The sfc cold front will push eastward throughout the day Tuesday approaching the local area late on Tuesday into Wednesday. It will slow and become near stationary over MS/AL/GA on Wednesday. As a result, chances for rain/storms will increase Tuesday night into Wednesday along and ahead of the frontal boundary with continued rounds of activity on Wednesday and Thursday as a series of shortwaves transition along the western edge of the subtropical ridge over the TN Valley as plenty of moisture remains in place along the stalled frontal boundary. Morning CAMs coming in are backing off significantly in precip chances with the initial precip coming in tomorrow night with the cold front. Any notable precip chance remain west of I-65 until after sunrise on Wednesday but that still may be too high if trends continue. Rain chances will peak Wednesday and Thursday during the daytime hours between 70%-90% both days. Shear profiles aren't impressive at this time and the severe threat remains low but will feel very summer like in terms of convection with sufficient instability, moisture, and lift in place to fuel these rounds of activity. We are included in a "Marginal" risk for Excessive Rainfall by WPC for Wednesday and Thursday but any rainfall will be beneficial at this point and QPF totals are not anticipated to result in any sort of impactful flooding outside of ponding on roadways where localized higher amounts are seen. High temps will remain above normal on Tuesday before moderating mid- week into the low/mid 80s under increased cloud cover and weakening ridge. && .LONG TERM... (Thursday night through Sunday) Issued at 1045 PM CDT Sun May 17 2026 This pattern will continue largely unabated from Thursday night into the weekend, with a broad summer-like subtropical ridge centered near Bermuda and deep SWRLY flow persisting across the TN Valley. A series of shortwaves are expected to ride along the trough/ridge interface across the region and bring bouts of increased shower/storm activity. Timing this is difficult, as the distinct nature of these shortwaves is difficult to discern in the model guidance. Nevertheless, increased instability during the daytime will certainly act to regulate chances for showers/storms during the period. Thermo profiles during the Thurs-Friday period do not appear to change significantly, with generally moist- adiabatic type profiles in the increasing deep/humid airmass. PWs climbing to near 1.7 inches and only modest CAPEs and weak-modest shear would suggest the largest threat may be due to any localized flash flooding that could result, especially with the prospect for slow-moving training storms. Shear may increase a little into the weekend, but still would characterize as modest at best. Overall, this is reminiscent of a warm, early summer pattern with highs mostly in the 80s and warm nights with lows in the 60s. && .AVIATION... (12Z TAFS) Issued at 602 AM CDT Mon May 18 2026 VFR conditions are forecast through the TAF period with southerly, breezy conditions up to 18 kts this afternoon. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...KG SHORT TERM....KG LONG TERM....KDW AVIATION...HC  018 FXUS64 KMOB 181533 AFDMOB Area Forecast Discussion National Weather Service Mobile AL 1033 AM CDT Mon May 18 2026 ...New UPDATE... .KEY MESSAGES... Issued at 1032 AM CDT Mon May 18 2026 - A HIGH risk of rip currents is in effect for all area beaches on Tuesday. - Rain chances increase by mid to late next week, especially over the northwestern portion of the forecast area. - Localized patchy fog will be possible late tonight into early Tuesday morning. && .UPDATE... Issued at 1032 AM CDT Mon May 18 2026 Have updated to increase highs by 2-3 degrees today mainly over a portion of the southern half of the area based on the latest trends. Made other minor adjustments. /29 && .DISCUSSION... Issued at 1025 PM CDT Sun May 17 2026 Dry weather conditions generally prevail for most areas today outside of perhaps an isolated shower or storm over the interior this afternoon, best chances near the Highway 84 corridor. Rain chances gradually increase into mid and late week as upper ridging weakens and southwest flow aloft works its way into the area along with several weak shortwaves. This should be enough to generate isolated to scattered shower and thunderstorm coverage each day starting Wednesday. Rain chances continue to look like they will be best this weekend as a weak upper trough pushes across the region. Overall for those who see storms it will be a beneficial rainfall to continue chipping away at our ongoing drought across the forecast area. We will probably see some patchy fog across portions of the area through daybreak this morning and again Tuesday morning. The better signal for fog, some locally dense, appears to be Tuesday morning. Fog will generally lift pretty quickly after daybreak. Outside of the rain chances, temperatures will be warm near or just above normal for this time of year on both highs and lows throughout the week. Highs generally fall in the 85 to 90 range, warmest Wednesday where some spots across the FL panhandle into south-central AL make it to the lower 90's. Lows warm with time from upper 50's to middle 60's this morning to middle 60's to lower 70's by mid week. The rip current risk remains Moderate today, becoming High Tuesday before dropping back to a Low to Moderate risk Wednesday into late week. MM/25 && .AVIATION... (12Z TAFS) Issued at 608 AM CDT Mon May 18 2026 IFR to MVFR ceilings have developed across the area this morning but will quickly give way to MVFR and VFR ceilings this morning. Winds will be out of the south-southeast around 10 knots gusting to 20 knots. An isolated shower or storm cannot be rule out this afternoon; however, any impacts to aviation will be minimal. MVFR ceilings will develop this evening with some patchy fog possible mainly across inland areas of southeastern Mississippi after midnight. BB-8 && .MARINE... Issued at 1156 AM CDT Sun May 17 2026 A light to occasionally moderate southeasterly flow will prevail through Thursday. Seas will build slightly by Monday and Tuesday then diminish Wednesday into Thursday. /29 && .PRELIMINARY POINT TEMPS/POPS... Mobile 87 71 87 70 / 10 0 0 0 Pensacola 85 72 84 72 / 10 10 0 0 Destin 83 71 83 71 / 10 0 0 0 Evergreen 89 66 91 67 / 30 10 20 10 Waynesboro 88 71 90 70 / 10 0 10 10 Camden 88 68 89 69 / 30 0 0 10 Crestview 89 66 91 67 / 20 10 20 0 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...High Rip Current Risk from Tuesday morning through Tuesday evening for ALZ265-266. FL...High Rip Current Risk from Tuesday morning through Tuesday evening for FLZ202-204-206. MS...None. GM...None. && $$  027 FXUS65 KBOU 181533 AFDBOU Area Forecast Discussion National Weather Service Denver/Boulder CO 933 AM MDT Mon May 18 2026 .KEY MESSAGES... - Rain and mountain/foothill snow increases in coverage this morning with much colder temperatures arriving. - Accumulating snow for the mountains and the foothills. Only a few wet snowflakes possibly mixed in for the I-25 Corridor. - One last spring freeze possible on some of the plains Monday night. - Delay in the warming and drying trend for the week ahead, but still warmer and drier by Friday - next weekend. && .UPDATE... Issued at 933 AM MDT Mon May 18 2026 Snow was increasing over the mountains, with a heavy accumulating drizzle along the Front Range I-25 Corridor. Precipitation rates will increase as expected this morning through mid afternoon with the heart of QG forcing and band of heavier precipitation on the western slope moving in. It was thinning a bit as it moves this way, but still expect a 2-3 hour period of enhanced precipitation rates and even a possibility of a couple thunderstorms as this moves in. Given snow levels are lower already (down to about 6500-7000 feet in Larimer County), we added a Winter Weather Advisory for the northern Foothills as snow intensity should pick up to >1" per hour. Also there was even a narrow corridor of freezing drizzle in the higher foothills of Boulder County (7,500-8,500 feet) where deeper seeder/feeder action was not in play yet. That will change soon as deeper moisture arrives. We also added North Park to the Winter Weather Advisory considering heavier snow had begun falling there this morning and will continue through mid afternoon with rates 1" per hour or more at times. Finally, still can't rule out a few snowflakes mixing in with our rain in the I-25 Urban Corridor despite high surface wet bulb temps. Main opportunity would be with convective showers early to mid afternoon, and then into evening if precipitation lingers long enough under the influence of further cold advection aloft. && .DISCUSSION /Through Sunday/... Issued at 1222 AM MDT Mon May 18 2026 An upper level trough over the Great Basin will move across the area on Mon with favorable mid level ascent thru the aftn hours. At the sfc, upslope flow will be in place which will combine with the upper level trough to produce widespread precip across the area. Snow will occur in the mtns and higher foothills with several inches of accumulation. Have upgraded areas north of I-70 in the mtns to a warning as east facing slopes could see from 12 to 18 inches in some areas. Elsewhere will keep amounts in the advisory range. In the foothills, some of the higher areas may see 4 to 8 inches above 8000 ft with lessor amounts below 8000 ft. By Mon night precip should gradually decrease over the area during the evening hours. Overnight lows late Mon night into early Tue morning may drop down to freezing or slightly below across portions of the plains. For Tue, a disturbance will move across the area late in the aftn thru Tue night. As this feature moves across, there will be another round of precip over the higher terrain and across portions of the plains. Highs on Tue will remain cool as readings stay in the 50's across the plains. Looking ahead to Wed, an unsettled pattern will continue as decent lapse rates will combine with lingering moisture to produce a good chc of showers and thunderstorms over the higher terrain and portions of the plains. Most of the activity will occur in the late aftn and early evening hours. Highs will remain below normal as readings only reach the upper 50's to mid 60's across the plains. By Thu into Fri, latest data shows another upper level trough moving southeast towards the area. Not sure about the timing of this system, however, as it moves across should see another good chance of showers and thunderstorms. Temperatures both days will be in the mid 60's to lower 70's across the plains. For next weekend, will see a return to a drier and warmer pattern based on latest data. && .AVIATION /12Z TAFS through 12Z Tuesday/... Issued at 518 AM MDT Mon May 18 2026 Ceilings are currently bouncing between 300ft and 600ft at the TAF sites. These IFR and LIFR conditions are expected to continue through the rest of today and into tomorrow morning. Scattered light rain showers this morning will increase in coverage late this morning and early this afternoon, leading to multiple hours of rain showers and a few thunderstorms. Coverage should start to decrease near the TAF sites around 21Z to 23Z, leaving some scattered showers for the late afternoon and evening. Rain chances will decrease for the overnight period, but there still is a low chance (<30%) that a few showers could stick around. Ceilings will start to lift slightly for Tuesday morning, but they still look to remain below VFR thresholds. Winds today will generally be out of the north or east with periods of gusty winds late this morning at KDEN and KAPA. Variable gusty winds could also accompany any thunderstorms in the area. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 9 PM MDT this evening for COZ030- 031-034-035. Winter Storm Warning until 9 PM MDT this evening for COZ033. Freeze Watch from late tonight through Tuesday morning for COZ038>051. && $$ UPDATE...20 DISCUSSION...RPK AVIATION...AP  041 FXUS62 KKEY 181534 AFDKEY Area Forecast Discussion National Weather Service Key West FL 1134 AM EDT Mon May 18 2026 ...New DISCUSSION, MARINE, AVIATION, PREV DISCUSSION... .KEY MESSAGES... - Very warm and humid conditions over the next few days will lead to a generally moderate risk of heat illness with periods of high risk conditions. - Rain and thunder chances will remain on a plateau through tomorrow, and gradually decline thereafter. - A period of on and off breezy conditions over the next few days will help to mitigate some of the discomfort from warm overnight temperatures. && .DISCUSSION... Issued at 1130 AM EDT Mon May 18 2026 This morning has looked very similar to yesterday across the Florida Keys! Temperatures are currently in the mid to upper 80s with dew points in the upper 70s. This gives us heat index values in the mid to upper 90s, which is within a degree or two compared to this time yesterday. Our KBYX radar has been busy detecting pockets of shower activity across the area. The heaviest showers have remained to the south and southwest of the Lower Keys, so we guess the marine life may be enjoying it. It is almost a little surprising that there isn't more shower activity on radar. The 12Z KKEY sounding calculated a PWAT value of 1.84", which is very close to the 90th percentile value of 1.86". The profile seems to be moist enough with only a couple of slots of dry air in the upper levels, but there is a small, shallow cap noted at 935mb. Our initial guess as to why shower coverage may be lacking is that there isn't any notable synoptic scale feature to provide robust lift. The low level flow also appears to be fairly uniform. Low level wind speeds are roughly 15 to 20 knots, so any outflows that have been produced by collapsing showers haven't had the opportunity to collide with other outflows. Radar trends suggest that a drastic increase in shower coverage may not occur during the daytime hours, but hi res guidance is hinting that the best chance for this will be later this evening. Either way, the inherited 40 percent PoPs seem reasonable considering these factors. No changes or updates are needed with this morning update. && .PREV DISCUSSION... Issued at 440 AM EDT Mon May 18 2026 Additional moisture to our east should pivot in throughout the rest of today. This combined with an already accelerated flow, should help to smash any mesoscale boundaries out there, allowing for showers to increase in coverage again. This enhanced moisture pool will linger through tonight and gradually begin scouring out starting Tuesday. This will not be a fast process and rain chances will be slow to diminish through the week. Meanwhile, a high pressure near Bermuda will flatten over the next several days, weakening the pressure gradient through the end of the week. This will lead to generally a slackening of winds, though there will still be some peaks in the evenings at times. By the end of the week we may have an easterly undulation move through the Bahamas and along the east coast of Florida, injecting more moisture back across the area, and subsequently rain chances. It's too far out to get our hopes up at this time. && .MARINE... Issued at 1130 AM EDT Mon May 18 2026 Small Craft Should Exercise Caution across all Florida Keys local waters due to east to southeast winds of 15 to 20 knots. From synopsis, surface high pressure centered near Bermuda will continue to promote moderate to fresh east to southeast breezes through the next couple of days. Breezes then undergo a very slow slackening process with peaks expected during the evenings and lulls during the day. Rain and thunder chances will remain above normal through much of the week. && .AVIATION... (15Z TAFS) Issued at 1036 AM EDT Mon May 18 2026 VFR conditions will prevail at both island terminals with FEW to SCT skies based between FL020 and 030. Short lived pop up showers will continue to traverse the area, and may clip either air field at virtually any point in the TAF period. Opting to keep the beginning of the package free of showers, and introducing VCSH from 20Z onward. && .PRELIMINARY POINT TEMPS/POPS... Key West 91 80 91 80 / 40 40 40 30 Marathon 87 79 86 80 / 40 40 40 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...DP Aviation/Nowcasts....DP Data Acquisition.....DP Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest  236 FXUS63 KIWX 181540 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 1140 AM EDT Mon May 18 2026 .KEY MESSAGES... - Strong to severe storms are likely today between 12 PM to around 8 PM EDT. Damaging wind gusts to 60 mph and heavy rain are the main threats. Low but non-zero risk for large hail and an isolated tornado. - Strong to severe storms are anticipated again Tuesday afternoon and evening, with all hazards possible. - Warm and humid through Tuesday with highs in the mid to upper 80s. - Cooler with seasonable temperatures and dry midweek. Highs only in the 60s Wednesday and Thursday. && .DISCUSSION... Issued at 1014 AM EDT Mon May 18 2026 Main focus this forecast period is on the severe potential for today and on Tuesday. For today, seems the one limiting factor for today's storms will be the available shear, with values of Bulk Shear is around 20 to 30 kts, this should keep organization of storms minimal and current convective allowing guidance and thinking points to a more linear feature moving northeastward into the area over the next couple of hours from central IL. A plume of dew points in the mid 60s is pushing northeastward ahead of the convection currently pushing across central IL. Surface based CAPE values will run about 2000 to 2500 J/kg over the CWA. With environmental profiles drier near the surface and a moist plume maxing out around 850 mb this creates an inverted-V sounding which is indicative of gusty outflows/winds with thunderstorms this is further illustrated with Downdraft CAPE values around 1000 J/kg. Storm relative helicity values look to remain below the 100 m2/s2 threshold but there is the possibility for an isolated tornado or two. This first batch of storms will move through after Noon EDT and push through the area into this evening til around the 8 PM EDT timeframe. Moderate to heavy rainfall will accompany these storms with precipitable water value sitting around 1.70 inches. Of course, the storm motion speed will be important as if the line moves through quicker that will limit the rainfall amounts but either way looks like we should get a pretty good slug of rain with today's event as trailing stratiform will bring some moderate steady rainfall behind the initial line of thunderstorms as it pushes eastward through the area. Storm totals over the next two days looks to see some areas seeing close to an inch of new rainfall. A break in the action takes place tonight into the overnight period before the better looking set up arrives tomorrow in the form of a cold front associated with a low pressure circulation centered over northern WI. SB CAPE values will be around 1500-2500 J/kg, surface dew points will get into the upper 60s with a few locations seeing lower 70s, bulk shear values 30-40 kts, and mid level lapse rates around 6 deg/km and helicity values of 100-200 m2/s2. At this time it looks as if all threats will be on the table with the better helicity and shear values associated with the close proximity of the frontal boundary that will push eastward through the area. The exact timing is still a bit hazy but current indications have the frontal boundary approaching the western portions of our CWA around 1 PM EDT and exiting the area by early morning Wednesday. SPC currently has our entire area in a slight risk for severe thunderstorms for Tuesday. Heavy to moderate rainfall will once again be possible with the thunderstorms and as stated earlier that around 1 inch of new rainfall will be possible with these two batches of storms and locally heavier amounts if the residence times of thunderstorms linger. In the wake of the cold front a more zonal flow develops over the region on Wednesday and cooler and drier conditions will arrive. Highs on Wednesday will only get into the 60s which is about a 20 degree drop from the 80s today and Tuesday. Upper level ridging begins to push into the region by Thursday and will start to see a gradual increase in temperatures into the weekend. Highs Friday and Saturday will be in the 70s. Sunday into the beginning of next week highs will return int 80s. Chances for afternoon showers and thunderstorms will also increase over the weekend and at this time the best chances will be Friday afternoon and evening with a trough pushing through the area but periods of showers/t-storms will be possible each day into next week. && .AVIATION /12Z TAFS THROUGH 12Z TUESDAY/... Issued at 604 AM EDT Mon May 18 2026 Minimal changes made to the 12Z TAFs. VFR conditions will continue through midday. A decaying MCS out of Iowa and Missouri has produced an outflow boundary in Illinois and storms are forming along it. This complex of developing storms is expected to weaken over Illinois this morning and then reintensify over northern Indiana around 18Z becoming strong to severe. Breezy southerly winds will gust as high as 30 kts today, even outside of any showers or storms. The strongest storms may end up east of IN-15 towards KFWA, but have maintained a PROB30 at KSBN for 17-20Z and a few hours later at KFWA from 19-22Z. MVFR ceilings and visibilities possible within any storms. The main threats today will be heavy rain and damaging wind gusts up to 50kts. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Andersen AVIATION...Johnson  615 FXUS63 KDTX 181548 AFDDTX Area Forecast Discussion National Weather Service Detroit/Pontiac MI 1148 AM EDT Mon May 18 2026 .KEY MESSAGES... - Warm and humid conditions exist today and Tuesday. This brings the risk for severe weather each day, mainly during the afternoon and evening hours. Thunderstorms will be capable of producing damaging winds, large hail and isolated tornadoes. - Cooler and drier conditions expected Wednesday and Thursday. && .UPDATE... The setup for severe thunderstorms remains favorable for SE Mi this afternoon and evening with the primary hazard being damaging wind gusts. Instability trends are certainly on track as full morning sun has already lifted temperatures into the lower 80s all areas with a few mid 80s reported leading up to the noon hour. The 12Z DTX sounding is also capped around 750 mb, enough to allow buildup of but easily eroded by the inbound MCV. Model MLCAPE forecasts up around 2000 J/kg in HREF mean and RAP projections are then within reach by mid afternoon to establish a receptive downstream environment for the ongoing convective complex as it moves NE into the area. 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, however this is where the most uncertainty lies in terms of downstream persistence. Model projections really struggle to maintain 0-6 km bulk shear above 25 knots which suggests the system enters SE Mi near full strength but is open to gusting out at some point while crossing SE Mi and exiting into Lake Huron and Ontario by early evening. && .PREV DISCUSSION... Issued at 500 AM EDT Mon May 18 2026 AVIATION... VFR conditions will prevail through the morning hours as southwest winds strengthen. Breezy conditions expected by late this morning through the afternoon with 25 to 30 knot gusts. A broken line of rain and thunderstorms is then expected to take shape this afternoon to the early evening with main timing between 19Z and 01Z. MVFR to possible IFR conditions will accompany the thunderstorms. Once the line passes, a period of clearing in lower clouds will develop before lower scattered clouds may build back in toward sunrise tomorrow. D21/DTW Convection... A broken line of rain and thunderstorms is expected between 20Z and 01Z. Period of MVFR to possible IFR conditions will accompany the thunderstorms. DTW THRESHOLD PROBABILITIES... * Moderate for thunderstorms this afternoon. * Low for ceilings aob 5000ft through this morning. Moderate with thunderstorms this afternoon. PREV DISCUSSION... Issued at 307 AM EDT Mon May 18 2026 DISCUSSION... Warm frontal boundary responsible for the prolific hail producing supercellular activity across portions of the Saginaw valley and northern thumb late Sunday will finally ease north of the region this morning as higher magnitude warmth increases influence within deepening southerly flow. Benign conditions ensured thru late morning as stability holds under modest capping. Influx of higher quality moisture will commence during this time, establishing a notable moisture gradient from west to east by early afternoon /dewpoint of mid 60s west to upper 50s east/. This affords a moderate level of diurnal boundary layer destabilization for at least western sections. Given an afternoon temperature of middle 80s, mlcape projection of upwards of 1500-2000 j/kg will peak across the Saginaw valley and down through the Highway 23 corridor. This leaves a receptive downstream environment for potential reorganization/ expansion of any MCV governed remnant nocturnal convective activity spilling downstream. A fairly strong model consensus exists on this scenario, targeting lower Michigan for a mid-late afternoon increase in coverage. A broader threat window locally between 19z and 01z with dependence on pace of the MCV. The background wind field remains modest, but subject to a localized meaningful increase both across the lower levels and with greater depth as the feature moves through. Supportive environment to offer a risk of both large hail and damaging wind gusts, with greater overall potential with westward extent. A focused area of higher SRH does materialize as low level flow backs briefly with a slight shift in the pressure gradient orientation. Therefore, cannot completely discount the possibility for a more organized, rotating updraft to present a brief, isolated tornado threat. Outside of the convective window, forecast continues to highlight gusty southerly conditions reaching 30 to 35 mph at times today. The seasonably warm and humid conditions will exist again Tuesday ahead of a cold front. A more muddled early day picture in terms of both cloud cover and precipitation chances, as a portion of the model solution space suggest possible activity prior to 18z owing to some combination of the ongoing moisture advection and remnant midwest convection leftover from tonight. Degree and pace of destabilization certainly still subject to change. Assumption for at least a weakly unstable environment timed favorably with an evening cold frontal passage will present an opportunity for deeper updrafts to organize within a sufficient background deep layer wind field along the frontal zone. The SPC Day 2 outlook maintains a slight risk designation to highlight the associated strong wind and large hail threat for the late Tuesday period. Warm sector environment will again become diurnally gusty, with winds reaching 30 to 35 mph from the south at times. Notably cooler post-frontal environment arrives Wednesday. This will occur with the backdrop of increasing low to mid level ridging, ensuring a stretch of dry and stable conditions lasting into Thursday. Low level thermal trough marked by 850 mb temperatures of lower single digits, lending to below average readings during this time. Coldest conditions Thursday morning as the surface high centers locally - lows dipping into the 30s in some locations. Dry conditions likely to hold under a modest warming trend Friday, as the next system organizes upstream. This system will introduce the next chance of rain Friday night into Saturday. MARINE... A warm front releases north across Lake Huron this morning, with southerly winds expanding across all local waters. Strong low level jet winds will struggle to mix down over the open waters where cool water temperatures maintain stable over-lake conditions. Gusty southwest flow will thus be confined to the nearshore waters, aided by warmer water temperatures and land influence. Frequent gusts today and Tuesday are expected to hold between 25 and 30 knots, but an isolated gust to 35 knots over Saginaw Bay cannot be entirely ruled out. Small Craft Advisories are in effect for today and will be needed Tuesday as well. More localized wind/wave impacts arrive with thunderstorm activity this afternoon-evening, and again Tuesday when a cold front sweeps through the area. There is potential for some of these storms to be strong to severe with all modes of severe weather in play. The cold front comes through Tuesday night, followed by high pressure filling in mid-week to support a quieter and more seasonable late May pattern. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...Small Craft Advisory until 10 PM EDT this evening for LHZ421-422- 441>443. Lake St Clair...Small Craft Advisory until 10 PM EDT this evening for LCZ460. Michigan waters of Lake Erie...None. && $$ UPDATE.......BT AVIATION.....AA DISCUSSION...MR MARINE.......MR You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.  663 FXUS66 KMTR 181550 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 850 AM PDT Mon May 18 2026 ...New UPDATE... .KEY MESSAGES... Updated at 1147 PM PDT Sun May 17 2026 - Breezy to windy conditions, especially across the North, East, and South Bay Mountains and the Santa Cruz Mountains through today - Hazardous beach conditions through this morning - Hazardous marine conditions expected through today - Elevated fire weather concerns continue through today across the interior with low humidities and strong gusts && .UPDATE... Issued at 842 AM PDT Mon May 18 2026 Gusty offshore winds continue through this morning with winds gradually easing this afternoon/evening. The Wind Advisory remains on track to expire at 11AM PDT across the higher elevations. Notably, the current hourly temperatures are running 6-7 degrees above what the current forecast has. This is likely due to the stronger offshore (NE) winds bringing in warmer and drier air, with some additional warming from downsloping occurring at the base of the mountains. Bumped temperatures up using the NBM90th percentile to better account for the already warmer temperatures observed this morning. This puts the interior into the 80s to low 90s today with the coast staying in the 70s. Winds don't look to switch onshore again until after peak heating (3/4PM) so would not expect much marine influence on today's high temperatures outside of the direct coastline. && .SHORT TERM... Issued at 1147 PM PDT Sun May 17 2026 (Tonight through Monday) An upper level low pressure system digs into the tri-state area of CO, UT, and WY by late Monday morning. We remain under the influence of the broader trough associated with it, leading to breezy offshore flow. North to northeast winds pick up tonight across the Santa Cruz Mountains, the interior North Bay Mountains, and the Eastern Santa Clara and East Bay Hills. Sustained wind speeds of 15 to 30 mph along with gusts up to 50 mph, though localized gusts up to 60 mph are expected for favored ridges, gaps, and passes. These winds will usher in drier air to the region as well, keeping the fire weather threat elevated for interior Bay Area and Central Coast locations. In terms of more every day hazards from the winds, impacts include, but are not limited to difficult driving, especially for high profile vehicles, downed tree limbs, the potential for power outages, and the possibility of loose or unsecured items being blown around. Winds begin to ease late Monday morning into the afternoon and will continue to decrease into the evening and overnight hours. Offshore winds should bring some warmer temperatures to the region, the 90s for the interior Bay Area valleys, the 60s to low 70s along the coast, and the mid 70s to low 80s for the Central Coast Valleys. && .LONG TERM... Issued at 1147 PM PDT Sun May 17 2026 (Tuesday through next Sunday) Upper level troughing looks to hold just west of the Desert Southwest and into southern CA Tuesday into Wednesday, leaving us with teetering between quasi-zonal and barely trough-y. Weak offshore lingers at least over the interior mountain ranges through Tuesday into Wednesday, with onshore flow trying to make a diurnally driven push each afternoon/evening. During this time high pressure just to the west of us (over the eastern Pacific) builds, pushing towards the coast mid week. The upper level trough begins to meander south to southwest of southern California late week. This should bring a return of onshore flow to the region and perhaps the marine layer. Current guidance suggests we could see a 500ft marine layer return by Wednesday, with a 1000-1200ft marine layer by Thursday and Friday. Will need to keep an eye on this as it will affect how temperatures pan out. && .AVIATION... (12Z TAFS) Issued at 449 AM PDT Mon May 18 2026 Strong winds aloft continue to move through the region causing widespread LLWS (both in speed and directions)into the mid to late morning. Gusty winds will be possible across most sites north of the Monterey Bay through the morning. Winds aloft decrease into the mid to late morning and begin to match up with moderate to breezy surface winds. The general wind pattern switches from northerly to westerly into the night, with winds becoming light into the late night. Haze from sea spray will continue to affect the coast. Vicinity of SFO...VFR through the TAF period. Gusty northerly winds continue to affect the terminal with even stronger winds aloft, leading to LLWS. Winds aloft reduce slightly and align better with gusty surface winds in the mid morning. Gusts reduce into the mid afternoon and winds turn more northwest before winds turn light into the night. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...VFR through the TAF period. Surfaces wind stay light through the morning with stronger winds aloft continuing to offer LLWS. Expect surface winds to increase and turn northwest into the late morning, while winds aloft reduce. Moderate northwest winds will ease and become light into the night, with MRY going southerly. && .MARINE... (Today through Saturday) Issued at 449 AM PDT Mon May 18 2026 Winds are reducing across the marine environment, but widespread gale- force gusts are no longer expected. Seas and winds will still offer hazardous conditions for small craft into the mid weak before easing for most zones. Winds will remain hazardous for small craft into the late week for the northern outer zone. && .FIRE WEATHER... Issued at 449 AM PDT Mon May 18 2026 Strong and gusty north to northeast winds continue to affect the region. Expect peak gusts greater than 30 mph for most areas, with around 45 to 55 mph along through gaps and passes, and across higher terrain. These winds will begin to reduce in the late morning but remain breezy until the late night. Daytime humidity retentions loos to stay around 10- 25% across the interior regions and higher peaks, with limited overnight humidity recoveries. Humidities will be slow to recover into the work week as a light offshore flow will continue to affect the district. && .BEACHES... Issued at 449 AM PDT Mon May 18 2026 A Beach Hazards Statement remains in effect for west facing beaches along the Pacific Coast through 9 AM due to strong winds over the marine environment leading to hazardously strong wind waves and overall rough seas. Dangerous swimming, boating, and surfing conditions can be expected. Large breaking waves can overpower swimmers resulting in significant physical injury and increase the risk of drowning. Gusts will stay strong along the immediate coast, causing blowing and drifting sand and increased sea spray. Water rescue attempts may be hampered by reduced visibilities from the sea spray. Remember, NEVER turn your back on the ocean. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement until 9 AM PDT this morning for CAZ006- 505-509-530. Wind Advisory until 11 AM PDT this morning for CAZ504-512-514- 515. Coastal Flood Advisory until 3 AM PDT Tuesday for CAZ506. PZ...Gale Warning until 9 AM PDT this morning for SF Bay N of Bay Bridge. Small Craft Advisory until 9 PM PDT this evening for Mry Bay- Pigeon Pt to Pt Pinos 0-10 nm. Small Craft Advisory until 3 AM PDT Tuesday for Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory until 9 AM PDT this morning for Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory until 3 AM PDT Wednesday for Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory until 9 AM PDT Tuesday for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...KR LONG TERM....KR AVIATION...Murdock MARINE...Murdock Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea  825 FXUS63 KIWX 181554 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 1154 AM EDT Mon May 18 2026 .KEY MESSAGES... - Severe storms are likely today between 12 PM to around 6 PM EDT. Damaging wind gusts to 60 mph and heavy rain are the main threats. Low but non-zero risk for large hail and an isolated tornado. - Severe storms are anticipated again Tuesday afternoon and evening, with all hazards possible. - Warm and humid through Tuesday with highs in the mid to upper 80s. - Cooler with seasonable temperatures and dry midweek. Highs only in the 60s Wednesday and Thursday. && .DISCUSSION... Issued at 1014 AM EDT Mon May 18 2026 Main focus this forecast period is on the severe potential for today and on Tuesday. For today, seems the one limiting factor for today's storms will be the available shear, with values of Bulk Shear is around 20 to 30 kts, this should keep organization of storms minimal and current convective allowing guidance and thinking points to a more linear feature moving northeastward into the area over the next couple of hours from central IL. A plume of dew points in the mid 60s is pushing northeastward ahead of the convection currently pushing across central IL. Surface based CAPE values will run about 2000 to 2500 J/kg over the CWA. With environmental profiles drier near the surface and a moist plume maxing out around 850 mb this creates an inverted-V sounding which is indicative of gusty outflows/winds with thunderstorms this is further illustrated with Downdraft CAPE values around 1000 J/kg. Storm relative helicity values look to remain below the 100 m2/s2 threshold but there is the possibility for an isolated tornado or two. This first batch of storms will move through after Noon EDT and push through the area into this evening til around the 8 PM EDT timeframe. Moderate to heavy rainfall will accompany these storms with precipitable water value sitting around 1.70 inches. Of course, the storm motion speed will be important as if the line moves through quicker that will limit the rainfall amounts but either way looks like we should get a pretty good slug of rain with today's event as trailing stratiform will bring some moderate steady rainfall behind the initial line of thunderstorms as it pushes eastward through the area. Storm totals over the next two days looks to see some areas seeing close to an inch of new rainfall. A break in the action takes place tonight into the overnight period before the better looking set up arrives tomorrow in the form of a cold front associated with a low pressure circulation centered over northern WI. SB CAPE values will be around 1500-2500 J/kg, surface dew points will get into the upper 60s with a few locations seeing lower 70s, bulk shear values 30-40 kts, and mid level lapse rates around 6 deg/km and helicity values of 100-200 m2/s2. At this time it looks as if all threats will be on the table with the better helicity and shear values associated with the close proximity of the frontal boundary that will push eastward through the area. The exact timing is still a bit hazy but current indications have the frontal boundary approaching the western portions of our CWA around 1 PM EDT and exiting the area by early morning Wednesday. SPC currently has our entire area in a slight risk for severe thunderstorms for Tuesday. Heavy to moderate rainfall will once again be possible with the thunderstorms and as stated earlier that around 1 inch of new rainfall will be possible with these two batches of storms and locally heavier amounts if the residence times of thunderstorms linger. In the wake of the cold front a more zonal flow develops over the region on Wednesday and cooler and drier conditions will arrive. Highs on Wednesday will only get into the 60s which is about a 20 degree drop from the 80s today and Tuesday. Upper level ridging begins to push into the region by Thursday and will start to see a gradual increase in temperatures into the weekend. Highs Friday and Saturday will be in the 70s. Sunday into the beginning of next week highs will return int 80s. Chances for afternoon showers and thunderstorms will also increase over the weekend and at this time the best chances will be Friday afternoon and evening with a trough pushing through the area but periods of showers/t-storms will be possible each day into next week. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1149 AM EDT Mon May 18 2026 Primarily weather concern is an incoming squall line from the west. Observation stations have had episodes of G30KT, with at least one unofficial report of 58mph gust toward central IL. Timing was adjusted to TSRA to align with the latest storm motion. Behind this line, dry for the overnight hours unless stratiform rain back builds over KFWA (low confidence, but will monitor). Additional TSRA Tuesday, especially at KFWA, but just beyond this TAF period. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Andersen AVIATION...Brown  993 FXUS64 KAMA 181557 AFDAMA Area Forecast Discussion National Weather Service Amarillo TX 1057 AM CDT Mon May 18 2026 ...New FIRE WEATHER... .KEY MESSAGES... Issued at 1127 PM CDT Sun May 17 2026 - High-end critical to extremely critical fire weather conditions persist Today. - A cold front will arrive this evening bringing northerly winds and cooler temperatures. - Showers and thunderstorms are possible beginning as early as Tuesday night and extending through Saturday. && .SHORT TERM... (Tonight through Tuesday night) Issued at 1127 PM CDT Sun May 17 2026 Currently, a dryline boundary over the eastern combined Panhandles has begun its retreat west. Although we have observed isolated attempts at convective initiation, updrafts have not been able to sustain as convection moves off the boundary. Tonight, RH recovery is dependent on both a weak cold front in the north and the retreating dryline in the east. Current guidance points toward a weak cold front pushing into the Oklahoma Panhandle tonight, which would bring with it increased RH values and a W to even NW wind shift in the western OK Panhandle and NW TX Panhandle. This weak cold front, and the dryline retreating west overnight could put the majority of of the Panhandles in decent (greater than 50%) Rh recovery. However, it will likely leave the western TX and north-central TX Panhandle counties in quite poor RH recovery overnight (20-30%). An upper-level trough will swing from the southwestern US, through the 4-corners, and into the plains through the course of tonight and tomorrow. This will re-establish a lee-side surface low pressure system in eastern CO. The cold front that pushes into the northern CWA tonight will retreat as southerly/southwesterly winds strengthen to the south of the front and the low strengthens. As the low strengthens, and 850 mb support arrives in the form of a LLJ around 35-40 kts, surface winds are expected to respond with intensification in the Panhandles. Sustained winds could reach 30-35 mph across the Panhandles, with gusts up to 50 mph. Minimum RH's as low as 4%, with widespread minimums of 5-10% across the combined Panhandles will lead to critical to extremely critical fire weather conditions across the Panhandles. Thee dryline on Monday will push east throughout the day, and CAMs are in agreement that there will likely not be enough forcing present along it to initiate convection. However, a cold strong cold front is expected to push through the area on Monday night. The cold front will enter the OK Panhandle around 7-8 PM, reaching Amarillo around 10-11 PM. This cold front will bring increased relative humidity, but with the strength of the cold front and the tightening of the associated surface pressure gradient as it pushed through, it will likely bring some continued breezy post frontal winds from the north. So, although RH's will improve, winds will stay breezy (20-25 mph sustained) behind the front on Monday night. The cold front will knock down temperatures on Tuesday across the Panhandles. Low temperatures Tuesday morning could reach the low 30's in the NW CWA, while high temperatures will dip below average for most of the CWA. Ferguson && .LONG TERM... (Wednesday through next Sunday) Issued at 1127 PM CDT Sun May 17 2026 Southwesterly flow aloft will persist for the majority of the forecast period. With a deeper trough axis in the SW, with the base extending south of CA, the surface level response to shortwave perturbations will likely be low-pressure centers in NM rather than CO. This would place us in the true warm sector of a weather pattern. This signal seems to persist from Wednesday through at least Saturday at this time. Greater confidence in severity and timing of showers orthunderstorms will be gained in the short term, as the atmosphere will likely still be recovering from the last weather system, persistent cloud cover could reduce severe chances, and the signal/synoptic support for this system is less forthright than the last. However, the signal is there, and if the atmosphere is able to build instability and avoid workover from multiple days of weather, showers and thunderstorms (possibly severe) are on the table. Ferguson && .AVIATION... (12Z TAFS) Issued at 634 AM CDT Mon May 18 2026 Brief MVFR conditions to start the 12Z TAF period at KAMA due to low cigs, but should quickly return to VFR by 14-15Z. VFR conditions then expected at all TAF sites throughout the remainder of the TAF period. Winds will be out of the southwest at 10-20 kts to start, increasing to 20-30 kts with gusts around 40 kts starting around 16-17Z through about 00Z Tuesday before diminishing to 10-20 kts around 06Z and continue through the end of the TAF period. Skies will be mostly clear. && .FIRE WEATHER... Issued at 1053 AM CDT Mon May 18 2026 With extremely critical fire weather conditions still expected to materialize this afternoon and evening, the arguably greatest factor of concern lies with any existing fires and the arrival of a cold front to the region later this evening. This front dropped further south than models anticipated this morning, helping higher humidity and cooler temperatures linger across the NW and central Panhandles. Unfortunately, there are no favorable parameters for these conditions to linger through the day, and the front should easily retreat northward allowing drier air and southwest winds of 25-35 mph gusting up to 50 mph to take over the rest of this afternoon-evening. The cold front will fully breach the Panhandles this evening, quickly shifting winds out of the north at 15-25 mph gusting up to 35 mph (10-20% chance for a few gusts >40 mph). Better moisture behind the front will help humidity values greatly improve overnight (60-90% RH), but the initial wind shift will pose a significant risk for any existing fires to spread rapidly southward. This front is currently projected to reach the OK Panhandle as early as 6-8 PM, the northern and central TX Panhandle as early as 8-10 PM, and the I- 40 corridor by 10 PM to midnight. We will monitor the timing of the front closely through the day. Harrel && .AMA WATCHES/WARNINGS/ADVISORIES... TX...Red Flag Warning until midnight CDT tonight for TXZ001>020-317. Wind Advisory until 8 PM CDT this evening for TXZ001>020-317. OK...Red Flag Warning until midnight CDT tonight for OKZ001>003. Wind Advisory until 8 PM CDT this evening for OKZ001>003. && $$ SHORT TERM...23 LONG TERM....23 AVIATION...29