Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX
Issued by NWS Austin/San Antonio, TX
854 FXUS64 KEWX 101136 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 636 AM CDT Sun Aug 10 2025 ...New AVIATION... .SHORT TERM... (Today through Monday) Issued at 1230 AM CDT Sun Aug 10 2025 An inverted trough is making its way across the Coastal Plains and will remain over our area through the weekend into early next week. While the accompanying moisture is somewhat muted aloft, the trough is nudging high-pressure westward and giving a little more room for low-level moisture to push inland. This will set up chances for isolated storms over the Coastal Plains this afternoon. Given the weakened ridging, a few isolated showers and storms could reach the I-35 corridor and eastern Hill Country by the late-afternoon or early evening before the rain fizzles after sunset. Similar weather is forecast Monday with the inverted trough pushing a little more inland, though an approaching trough over the Central US should keep the inverted trough axis east of the I-35 corridor. This brings another opportunity for isolated showers and storms during the afternoon and early evening with a little more westward extent, though the best chances are still over the Coastal Plains where moisture is highest, decreasing farther west. High temperatures Sunday and Monday depend on the timing of the arriving rain-enhanced seabreezes, but the mostly isolated nature of storms should allow highs to reach the 90s with temperatures near 100 over the drier Rio Grande Plains. && .LONG TERM... (Monday night through Saturday) Issued at 1230 AM CDT Sun Aug 10 2025 .KEY MESSAGES... - Slightly less stable conditions later in the week could signal a shift toward increasing rain chances. - Seasonably hot weather should continue with a near flat trend on high temperatures. Correction to the previous AFD. The inverted trough pattern is maintained Tuesday and is joined by falling heights from a polar trough to set up a broader N-S shear axis across TX which continues to signal increasing rain chances. Energy slipping southward from the Southern Plains might lead to the better rain chances concentrating farther inland and over the higher terrain areas of the Edwards Plateau and Hill Country. The near 50 percent rain chances there Tuesday afternoon could lead to some locally heavy downpours given the shear axis favoring slow storm motions. PWat values from the GFS/NAM suggest mainly 1.6 to 1.8 inch values which is enough to support some heavy downpours, but nothing of the scale seen from the shear axis over the region from early July. Nevertheless, there will be increasing attention toward this region as the 00Z runs of the GFS/ECM seem to suggest a slow recovery back to upper ridge dominance and potentially a weak tropical wave lifting from the Central Gulf into this pattern by Friday. We`ll hold off making any changes into that part of the extended for now and see if the weak wave feature survives the next model run or two before ramping up rain chances for Friday into Saturday. There`s always a good chance the 00Z cycles were a wet outlier, leading to inconsistent forecasting. Also, the MEX guidance does not seem to mesh with the less stable pattern, so the ECM based guidance would make more sense for max temperatures. && .AVIATION... (12Z TAFS) Issued at 617 AM CDT Sun Aug 10 2025 A couple pockets of MVFR cigs might impact SAT and AUS through 13Z. Satellite imagery suggest the cloud areas to be shifting east, leaving VFR skies for the terminals after 13Z. MOS guidances have been poor at catching these patchy stratus, so will go ahead and include a scattered deck in the 24-30 hour windows. Isolated SHRA could form just east of I-35 and bring a potential for shifty and breezy conditions for a 2-4 hours either side of 00Z. An isolated clap of thunder can`t be ruled out, but there doesn`t look to be enough coverage to consider for a PROB30 at this time. The rest of the winds and sky will resemble a typical slow diurnal trend for mid- August with a few late afternoon and early evening gusts of 18-22 knots possible. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 97 76 96 76 / 20 0 20 10 Austin Bergstrom Intl Airport 97 74 96 75 / 20 0 20 10 New Braunfels Muni Airport 97 73 97 73 / 20 10 20 10 Burnet Muni Airport 95 73 94 73 / 0 0 20 10 Del Rio Intl Airport 100 78 100 78 / 0 0 10 10 Georgetown Muni Airport 97 75 96 75 / 10 0 20 10 Hondo Muni Airport 98 73 97 73 / 0 0 10 10 San Marcos Muni Airport 98 73 97 73 / 20 0 20 10 La Grange - Fayette Regional 95 74 95 74 / 20 10 30 10 San Antonio Intl Airport 97 75 97 76 / 20 10 20 10 Stinson Muni Airport 99 75 98 76 / 20 10 20 10 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...Tran Long-Term...18 Aviation...18