####018007071#### FXUS64 KEWX 170740 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 240 AM CDT Sat May 17 2025 ...New SHORT TERM, LONG TERM... .SHORT TERM... (Today through Sunday) Issued at 1208 AM CDT Sat May 17 2025 Key Messages: - Hot conditions continue today with elevated heat index values over portions of South Central Texas. - Low to medium chances for isolated or widely scattered strong to severe thunderstorms this afternoon and evening. Thunderstorm activity has ended early this morning with only some lingering light showers in the west associated with the decaying storms. Showers will end well before sunrise with dry conditions expected the rest of the morning. Overcast skies have begun to build over the area allowing for another morning of warm lows in the 70s to right around 80 degrees for some locations along the Rio Grande. A few locations may also see patchy fog, mainly along and east of the I-35 corridor. Not to sound like a broken record, but another hot day is in store for this afternoon. Highs will peak in the mid to upper 90s for most of the southern Edwards Plateau, Hill Country, I-35 corridor and coastal plains. Along the Rio Grande, highs will likely be in the triple digits from around 100 to 105 degrees. As with previous days, dewpoints remain elevated allowing for heat indices from around 103- 107 over the I-35 corridor and coastal plains and up to 111 over the Rio Grande Plains. Opted to go without a Heat Advisory given the majority of locations look to stay below criteria, though would not be surprised if some isolated spots hit their thresholds. Heat safety measures should continue to be taken into early next week given the forecast. Additionally, this afternoon and evening there are low to medium chances for strong to severe thunderstorms, mainly across the Rio Grande, southern Edwards Plateau and Hill Country. Storms are expected to form ahead of the dryline, but coverage could be isolated or widely scattered for our area with decent model uncertainty on exactly where they will form. That said, any storm that does form could quickly become severe with large to very large hail and damaging wind gusts the main hazards. Activity should drop off with the loss of heating with drier conditions expected overnight. Lows tonight will depend on where storms form, but will generally be on the warm side again. Highs Sunday will be similar to those of today. Sunday afternoon should be mainly dry with only some low precipitation chances in the far northern Hill Country. && .LONG TERM... (Sunday night through Friday) Issued at 1208 AM CDT Sat May 17 2025 Key Messages: - Record breaking heatwave and heat related impacts continues with additional temperature records likely being broken Monday and possibly Tuesday. - Chances for showers and storms Tuesday with arrival of a cold front though confidence of timing and strength is low. The early record breaking heat continues Monday though air temperatures start slowly decreasing but the feels like remains in the 100-110 degree range through Tuesday. Several weak disturbances move into the region thus possibly limiting just how high actual air temps can go due to the increased moisture and abundant cloud cover. However, the increased moisture could actually cause our heat indices to be even warmer then what we have currently forecast, definitely something to watch for. One of these disturbances will impact our area late monday night as a shortwave moving through the southern Plains looks to send the dry line back east into the Hill Country and I-35 corridor into Tuesday, with a cold front eventually overtaking it Tuesday night. Confidence continues to remain low as models generally have a difficult time with such small scale features. The best chances still look to be along and West of the I-35 Corridor. Regarding temperatures the cold front mentioned prior could bring some temporary relief from the heat for Wednesday and Thursday, however confidence in the strength and position is low at this time. Regardless, temperatures will remain well above normal through the end of the forecast period with high temperature records likely to be tied or broken through Tuesday. Towards the end of the long term, temperatures cool somewhat into the low 90s vs the upper 90s/100s that we previously have been seeing. Please make sure you and your loved ones have a way to stay cool during this early season heatwave. Additional heat safety information and resources can be found at the following websites: www.heat.gov and www.weather.gov/safety/heat && .AVIATION... (06Z TAFS) Issued at 1203 AM CDT Sat May 17 2025 MVFR to IFR ceilings will build over much of the area overnight except near the Rio Grande where VFR conditions remain. Could see some patchy MVFR visibility as well this morning, including at KAUS. Ceilings should improve to VFR late this morning or early afternoon across all of South Central Texas. Isolated to widely scattered storms are expected to initially develop in the afternoon and evening in Mexico extending northeast into the Hill Country. There is the highest confidence in KDRT seeing -TSRA in the afternoon and a TEMPO group has been included. Lesser confidence is seen at I-35 terminals but a few models do show some activity near KSAT/KSSF so included PROB30 groups. && .CLIMATE... Issued at 236 PM CDT Fri May 16 2025 RECORD MAX TEMPERATURES SATURDAY THROUGH TUESDAY (* TIED RECORD WITH MOST RECENT OCCURRENCE SHOWN) SAT SUN MON TUE 05/17 05/18 05/19 05/20 ---------------------------------------------- AUS 97/2018 97/2022 97/2006 99/2008 ATT 99/2022 98/2022 98/2022* 101/2008 SAT 100/2022 101/2022 101/1989 100/1996 DRT 105/2013 107/2024 108/2020 105/1973 && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 95 74 98 75 / 20 20 10 0 Austin Bergstrom Intl Airport 96 74 97 75 / 20 10 0 0 New Braunfels Muni Airport 97 74 98 75 / 10 10 0 0 Burnet Muni Airport 94 72 95 74 / 30 30 10 10 Del Rio Intl Airport 100 79 103 78 / 30 20 10 10 Georgetown Muni Airport 95 72 96 74 / 30 30 10 0 Hondo Muni Airport 98 73 99 74 / 10 20 0 0 San Marcos Muni Airport 97 73 98 75 / 10 10 0 0 La Grange - Fayette Regional 93 75 95 76 / 10 0 0 0 San Antonio Intl Airport 98 76 98 76 / 10 10 0 0 Stinson Muni Airport 99 76 100 77 / 10 20 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...27 Long-Term...CJM Aviation...27 ####018006423#### FXUS61 KCLE 170743 AFDCLE Area Forecast Discussion National Weather Service Cleveland OH 343 AM EDT Sat May 17 2025 .SYNOPSIS... A low pressure system centered over the region will move a cold front east across the area today. High pressure will build south across the area on Sunday, persisting through Tuesday. Another low pressure will move east out of the Central U.S., impacting the area midweek. && .NEAR TERM /THROUGH SUNDAY/... A vertically stacked low pressure system will continue to meander east-northeast across the Great Lakes region into southern Ontario and Quebec today. This will allow a cold front to push east today which will mark a notable change in weather pattern. There is a potential for some scattered showers to redevelop along the cold front, especially in far NE OH and NW PA, however given limited instability and shear, not expecting any severe storms to develop. The more notable impact of this frontal passage will be the gusty winds observed across the area today. A decent gradient over the area will allow for southerly winds of 15-20 mph with gusts up to 30 mph this morning. Behind the cold front, winds will become westerly and increase to be sustained at 20-25 mph with gusts up to 30-35 mph (possibly a tad higher across western counties). These gusty winds coupled with cooling temperatures will result in a blustery Saturday across the area with highs only climbing into the low to mid 60s with the warmest temperatures isolated to the far southeastern counties. A few lingering light showers are possible tonight across NW PA as a lingering surface trough persist. Not expecting much in terms of coverage given the drier airmass pushing south with a Canadian high pressure. By Sunday, high pressure will become dominant, allowing for conditions to dry out across the entire area. Winds should steadily weaken late Saturday night into Sunday, with west-northwest winds of 10-15 mph, gusting up to 20 mph possible by Sunday afternoon. Overnight lows tonight will be much cooler than recent nights with temperatures falling into the low to mid 50s. Highs on Sunday will be a tad warmer, climbing into the mid to upper 60s with the warmest temperatures along and west of I71. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... Finally will get out of the dominant troughing over the eastern CWA with the eventual departure of the upper level low to the New England coast. This will be replaced by weak ridging aloft while the next low pressure system gets organized over the central plains region. High pressure influences from a center well north of the area over Hudson Bay in Canada will also find its way into the southern Great Lakes with a dry forecast through Sunday night, but this will serve to continue the cold northerly surface flow into the region. Back to the central plains region low pressure system, this will make eastward progress with a leading warm front towards the Ohio Valley. Large swath of low/mid level isentropic ascent ahead of the warm front brings POPs back into the fold for Tuesday from the southwest, heading into a wetter period in the long term portion of the forecast as this system moves into our area. Look for temperatures to be around 10 degrees or so below normal in the short term, a trend that will persist for a few days. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... Low pressure system moves eastward into southern Ohio midweek pushing moisture further north into the CWA for Tuesday night onward. Upper level low deepens over Lake Erie on Thursday into Thursday, and with the main forcing from the surface system now further east, general surface troughing and cold air advection showers will control the pattern heading into the end of the work week. Thursday will be the coolest day with most locations not getting out of the 50s for high temperatures. Temperatures will slowly modify towards the weekend, but will keep carrying lower end POPs Friday in the cold pool aloft. && .AVIATION /06Z Saturday THROUGH Wednesday/... Widespread VFR conditions are expected to persist for much of this period. There is a small chance that some terminals may briefly drop to MVFR in showers that move into the area, however confidence in the expanse of showers and exact location is low so opted to not include as prevailing, but opted to include as TEMPO for KCAK, KYNG, and KERI. As the cold front pushes east this morning, all terminals should dry out for the remainder of the period. After 00Z Sunday, ceilings will gradually diminish to MVFR heights. The primary aviation concern through this period will be strong, gusty winds at all terminals. Ahead of the cold front this morning, winds from the south-southwest will be sustained at 10-15 knots, gusting to 20-25 knots. Behind the cold front late this morning, winds will shift to become more westerly at 15-20 knots, gusting up to 25-30 knots. Near the end of the period, winds will remain from the west and weaken to 5-10 knots with gusts of 15-20 knots. Outlook...Non-VFR possible in low ceilings across the eastern half of the area on Sunday. Mainly VFR is expected Monday and Tuesday. Non-VFR is likely to return on Wednesday in widespread showers and thunderstorms. && .MARINE... After a cold front passes west to east across Lake Erie this morning, southwest winds 15-25kts become westerly 20-25kts and wave heights becoming 3-6ft over most of the nearshore and open waters. Westerly winds become northwesterly Sunday, easing to 10-15kts and wave heights down to 1-3ft. Onshore winds and wave heights 1-3ft continues through Monday, turning northeasterly Monday night through Tuesday 10-20kts and wave heights increasing again to 2-4ft. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...Small Craft Advisory until 10 PM EDT this evening for LEZ142>145. Small Craft Advisory until 10 AM EDT Sunday for LEZ146-147. Small Craft Advisory from 10 AM this morning to 8 AM EDT Sunday for LEZ148-149. && $$ SYNOPSIS...04 NEAR TERM...04 SHORT TERM...26 LONG TERM...26 AVIATION...04 MARINE...26 ####018004876#### FXUS63 KTOP 170744 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 244 AM CDT Sat May 17 2025 .KEY MESSAGES... - Severe weather potential increases during the afternoon and evening hours Sunday. Large hail and heavy rain will be the main threats, with some tornado potential particularly in far southern/western portions of the area. - Another round of severe weather potential comes Monday afternoon and evening. Large hail and damaging winds the main threat, though a few tornadoes will also be possible. - Cooler and quieter stretch of weather arrives Tuesday. && .DISCUSSION... Issued at 243 AM CDT Sat May 17 2025 A progressive upper pattern remains in place across the country this morning. The powerful upper low responsible for yesterday's severe weather across the Ohio Valley is centered over Wisconsin, while another strong trough begins to dig southeast over the West Coast. Ridging between the two troughs is currently keeping our area mild, dry, and quiet, as dewpoints remain in the 30s/40s. However this will change for the second half of the weekend as the West Coast trough quickly ejects eastward towards the Plains. With the approach of the western trough, moisture will quickly advect northward, and we should see a few elevated showers and thunderstorms as early as Saturday night. As we turn our attention to Sunday, there remain a lot of questions. And most of these questions are tied to the northward movement of the warm front, as guidance remains inconsistent in its placement by Sunday afternoon. I suspect a lot of this inconsistency is tied to the amount of clouds and convection that develop north of the front during the first half of the day. Widespread showers and storms often tend to hinder northward advancement in setups like this, and I do tend to lean slightly towards this scenario. This would also keep the main severe weather threat as large hail with elevated storms north of the front. However, if fewer clouds and precipitation develops north of the warm front, this could help it mix northward faster. This would also lead to more sunshine and heating along the boundary that would increase the potential for surface based storms to develop. Given backed surface winds and strong shear along the front, this scenario would be more concerning for tornado potential. The current forecast roughly splits the difference between these two scenarios. Large hail is kept as the main threat for most of the area, with the best chance for a tornado confined to far western/southern portions of the area along the most likely warm front position. Do think we'll be able to narrow in on this uncertainty throughout the day today as more high-res guidance comes in. Additional storms may develop farther west along the western/central KS dryline, however confidence is high that this separate area of development will stay well to our west. By Monday, the main upper trough will shift eastward, allowing a deep surface low and the dryline to move closer to eastern Kansas. A few models hint at convection developing late Monday morning across Oklahoma and moving northeast across southeast Kansas. This seems like an unlikely scenario, but could push some cloud cover across eastern Kansas if it occurred. Assuming this fly-in-the-ointment scenario doesn't pan out though, ample heating east of the dryline would allow for around 3000 J/kg of ML CAPE to develop. Coupled with 40-50 kts of mostly boundary parallel shear, this would be favorable for initial supercells with a very large hail and damaging wind threat. Low-level shear doesn't look all that high through early evening, but may increase enough by mid-evening that the tornado potential briefly increases with any still discrete supercell across east-central KS. Similar to Sunday, there remain some uncertainties that we hope to better resolve as we approach the event, so stay tuned. By Tuesday, there's good agreement in guidance that the upper trough axis will have passed to our east, pushing a cold front through eastern KS. This will keep the rest of the week drier and much cooler. Highs look to stay in the 70s Tuesday through Friday, with Wednesday likely sticking in the 60s amidst steady northerly winds. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1211 AM CDT Sat May 17 2025 VFR conditions with just a few high clouds will continue through the period. Northwest winds around or below 10 kts tonight gradually become more northeasterly by tomorrow evening. && .TOP WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Reese AVIATION...Reese