Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX
Issued by NWS Austin/San Antonio, TX
547 FXUS64 KEWX 271752 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 1252 PM CDT Wed Aug 27 2025 .KEY MESSAGES... - Isolated to widely scattered showers and storms this afternoon across the Coastal Plains, I-37/I-35 corridor, and Hill Country - Rain chances returning Friday across the northern Hill Country and Austin metro, spreading south Saturday, and peaking Sunday - Main storm threats Friday through Sunday are gusty winds in stronger storms and a Level 1 of 4 risk for excessive rainfall that could lead to isolated instances of flash flooding - Hot conditions Thursday and Friday, cooler Sunday into early next week && .SHORT TERM (THROUGH THURSDAY NIGHT)... A pool of higher precipitable water stretches from the Hill Country into the Coastal Plains. Within this region, weak forcing combined with heating has allowed isolated to widely scattered showers and thunderstorms to develop. These will continue through sunset, then gradually dissipate with loss of heating. Like yesterday with the activity, an isolated location could pick up a quick 1 to 2 inches. In addition, a few stronger wind gusts in excess of 40 mph are possible with any strong collapsing downdrafts. Thursday continues to remain the driest day of the week as the higher pool of moisture works northeast of the area. high temperatures warm a few degrees Thursday, into the upper 90s to around 100 for most areas, mid 90s across the Hill Country. && .LONG TERM (FRIDAY THROUGH WEDNESDAY)... The center of the ridge axis overheard Thursday shifts slightly west on Friday while forcing rides over the ridge and into the back side of the eastern CONUS trough. This will allow for a front to move south into central Texas Friday. South of the front, hot conditions will persist over south-central Texas, with temperatures a degree or two warmer than Thursday and peak afternoon heat index values in some areas in the 104-108 range. There is some uncertainty with exactly how far south the front makes it Friday afternoon, with storm chances (20-40%) across the northern Hill Country and Austin metro area late Friday afternoon and evening mainly associated with outflow boundary propagation from any storms along the front just to the north. As is the case with late August and early September cold fronts this far south, confidence in a push southward is often low. This front is no different and global models do struggle with how far south the progression of the diffuse front makes it Friday night through Saturday. This is leading to a lower confidence temperature and chance of rain forecast on Saturday. NBM continues to show higher rain chances (30-40%) draped northwest to southeast from the Hill Country into the Coastal Plains Saturday, and high temperatures closer to averages for this time of year. There is a signal in the global models that a mid and upper level disturbance in the northwest flow across west and central Texas will generate more widespread coverage of showers and storms Saturday night into Sunday morning across west and central Texas. This should help push the front farther south into or through our south-central Texas region Sunday and Sunday night, increasing our chances for showers and storms. This is reflective in the NBM rain chances increasing to 40-60% across the area Sunday. The region is currently under a Level 1 of 4 risk for excessive rainfall that could lead to flash flooding Saturday through Sunday night. Low rain chances (10-20%) could linger through the early to middle of next week as the front slowly washes out. Cooler temperatures in the mid 80s to lower 90s are forecast Sunday and Monday, with a warming trend closer to seasonal averages Tuesday and Wednesday. && .AVIATION (18Z WEDNESDAY THROUGH FRIDAY)... CIGs have lifted to VFR regionwide with FEW to BKN cloud cover. Isolated -SHRA is ongoing as of 18Z over a broad swath from AQO southeast to HYI to T20, including AUS, and should continue to around 00Z with isolated TSRA after 20Z. Low confidence in coverage leads to PROB30 for -TSRA being maintained at AUS for 21Z-00Z. SAT/SSF are on the fringes of this low confidence activity so no mention of TS in the 18Z TAFs, but trends are being monitored. Winds are predominantly southeasterly and near to below 10kt, but weaker flows near AUS could result in more variable directions today. After 09Z, patchy MVFR CIGs redevelop with greatest confidence near SAT and SSF before lifting 14Z-16Z, accompanied by a southwest to southerly wind near 10kt regionwide. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 75 98 77 99 / 10 0 0 30 Austin Bergstrom Intl Airport 74 98 76 99 / 10 0 0 30 New Braunfels Muni Airport 73 99 74 100 / 10 0 0 20 Burnet Muni Airport 73 95 76 95 / 10 0 10 40 Del Rio Intl Airport 78 100 78 102 / 0 0 0 0 Georgetown Muni Airport 73 97 76 98 / 10 0 10 40 Hondo Muni Airport 73 98 74 99 / 10 0 0 10 San Marcos Muni Airport 73 99 75 101 / 10 0 0 20 La Grange - Fayette Regional 74 97 75 97 / 10 10 0 20 San Antonio Intl Airport 76 99 77 100 / 10 0 0 10 Stinson Muni Airport 76 100 78 101 / 10 0 0 10 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...76 Long-Term...76 Aviation...Tran