Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX
Issued by NWS Austin/San Antonio, TX
700 FXUS64 KEWX 291849 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 149 PM CDT Fri Aug 29 2025 .KEY MESSAGES... - Above average heat and humid today and Saturday, then near to below average temperatures Sunday into next week. - Rain chances in the Hill Country and areas north of San Antonio today spreading south to include the San Antonio area on Saturday, then all areas Sunday into Monday. - Locally heavy rains possible today through Monday. The main threat is urban and small stream flooding with a slight risk of flash flooding. && .SHORT TERM (THROUGH SATURDAY NIGHT)... A cold front is draped across Central Texas today. South of this feature, some showers and isolated thunderstorms are seen which remain just north of the CWA early this afternoon. This activity will move south into the area with hi-res guidance continuing to generate thunderstorms through the evening mainly over the Hill Country and areas north of the San Antonio metro. The front remains in a similar location on Saturday with precipitation chances extended slightly further south into most of the southern Edwards Plateau, Hill Country, coastal plains and I-35 corridor as far south as San Antonio. Above normal PWATs are in place today and tomorrow which will allow for these slow moving storms to produce heavy rainfall and a threat of flooding each day. Spotty rainfall amounts up to 3 inches will be possible each day with stronger storms capable of producing wind gusts up to 50 mph. WPC continues its level 1 of 4 risk for excessive rainfall today and tomorrow, but mostly expect urban and small stream flooding in the short term period. Hot and humid conditions continue are seen today and tomorrow south of the front. Today will be the hottest with slightly more cloud cover expected on Saturday. Highs this afternoon will be in the mid 90s to around 103 degrees, but heat index values will surge from around 100-108 degrees. A few isolated locations may briefly reach heat advisory levels. Heat indices drop a degree or two for tomorrow. Either way, if you`re out this holiday weekend be sure to take heat safety precautions such as drinking water and taking breaks inside or in the shade. Additionally, if thunder roars, go indoors! && .LONG TERM (SUNDAY THROUGH FRIDAY)... A cold front shifts south into the area during the day Sunday bringing the highest rain chances of the week Sunday afternoon through Monday. Forcing by the front and heating will generate showers and thunderstorms over many areas between the two days. Precipitable water values exceed 2 inches for some locations which is above normal for the time of year indicating showers and thunderstorms will be efficient rain makers. Rain totals will vary but with slow moving storms or training storms, isolated totals up to 5 inches are possible which could lead to flash flooding. WPC has now upped the northern half of the CWA in a level 2 of 4 risk for excessive rainfall with a level 1 of 4 risk elsewhere Sunday into Monday morning. In addition to heavy rain, storms could produce gusty winds up to 40 mph. The front hangs out in South Texas on Tuesday leaving some low precipitation chances in the forecast, mainly in our southern and western locations, though most locations will be dry this day. Surface high pressure slides over the area mid to late week with a dry forecast for Wednesday and Thursday. Low rain chances return Friday, though models are pretty varied this far out. Rain chances and clouds bring the coolest temperatures of the week Monday, with temperatures rising to more seasonable values for the rest of next week. && .AVIATION (19Z FRIDAY THROUGH SUNDAY)... VFR conditions with south to southeast winds below 15kts can be expected for all TAF sites except KAUS through the entire forecast period. For KAUS low to mid level clouds are approaching the terminal from the northwest with some embedded showers and thunderstorms. Expect this trend to continue and as such have kept mention of PROB30s for 21Z to 24Z for -TSRAs however did keep VFR conditions and will amend as needed for this evening. Winds should start to become VRB due to possible outflow boundary from TSRAs and should continue being VRB as winds become light through the period. VFR conditions persist until possible MVFR conditions by 11Z tomorrow as more SHRAs and TSRAs are forecast. Have again added PROB30s to account for this tomorrow evening (18Z to 24Z). For KSAT and KSSF we don`t see chances for SHRAs and TSRAs until late in the TAF package (around 18Z tomorrow) have kept mention out for now as its unclear how far south the cold front makes it tomorrow and again will amend as needed as guidance continues to get closer. For KDRT expect VFR conditions with clear skies as the front doesnt look to impact the site until well outside the TAF forecast. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 76 96 75 89 / 30 40 40 60 Austin Bergstrom Intl Airport 75 96 75 89 / 30 30 40 50 New Braunfels Muni Airport 74 98 74 93 / 20 30 30 40 Burnet Muni Airport 73 92 73 85 / 30 50 50 80 Del Rio Intl Airport 79 102 79 99 / 0 10 10 30 Georgetown Muni Airport 74 95 74 85 / 30 40 50 80 Hondo Muni Airport 75 99 74 96 / 10 10 10 30 San Marcos Muni Airport 74 98 74 93 / 20 30 30 40 La Grange - Fayette Regional 75 95 75 90 / 30 40 30 70 San Antonio Intl Airport 77 99 78 95 / 20 20 20 40 Stinson Muni Airport 78 101 78 97 / 10 20 20 30 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...27 LONG TERM...27 AVIATION...Magnussen