Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX
Issued by NWS Austin/San Antonio, TX
282 FXUS64 KEWX 051134 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 634 AM CDT Fri Sep 5 2025 .KEY MESSAGES... - Above normal temperatures Friday. - Rain chances return this weekend with the potential for locally heavy rain and flooding. && .SHORT TERM (THROUGH SATURDAY)... Strong wind shear from the subtropical jet is carting off upper- level moisture from the weakening Tropical Storm Lorena in the eastern Pacific into our area, which will support the spread of cirrus over the region today and into the weekend. The center of mid- level ridging is now to our east, leading to the return of southerly flow across South-Central Texas. This will help raise dew points by about 10 degrees relative to where they were yesterday, so lows this morning will only reach the low to mid 70s for most. Even with the added moisture, an elongating thermal ridge will help drive temperatures to the upper 90s to around 100 across the area this afternoon. Heat indices are expected to top out at around 102 to 106 degrees over the more humid Coastal Plains. Most of the area is forecast to remain dry today, but a few showers and storms could start to move into the southern Edwards Plateau late in the day as the first bits of mid-level energy from Lorena start to pass over the region. The pattern starts to shift gears Saturday as a trough swinging across the Midwest pushes a frontal boundary into our area. Models have come into better agreement that the front should reach our area early Saturday with chances for isolated to scattered showers and storms along the front. Storm chances are slightly more favored over the Coastal Plains and over the southern Edwards Plateau where instability is slightly higher, though low to medium rain chances are seen for the entirety of South Central Texas. The front, rain- cooled air, and additional clouds will help keep temperatures cooler behind the front with a mix of 80s to low 90s during the daytime, while humid warmth with highs in the mid 90s could prevail over the Coastal Plains and Winter Garden areas with compressional heating ahead of the front. && .LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)... Saturday night into Monday, the main batch of moisture from the remnants of Lorena starts to push across Texas, guided by a shortwave trough incorporating some of the leftover vorticity from the former hurricane. The increased moisture and southerly low-level winds ahead of the trough look to modify the post-frontal environment, leading to rising instability and chances for rounds of showers and storms across South-Central Texas as the front lingers over the area. There is strong likelihood that a moist airmass with high precipitable water values will be present. However, with Lorena winding down off the Baja California instead of surviving the trek into the Desert Southwest, the trough helping to drive this rain potential looks to be a little more broad and strung out than previously modeled, increasing uncertainty in rain timing and coverage. Ensemble guidance has trended downwards in projected amounts and extent of the rains, though there continues to be some synoptic signals for locally heavy rain. Sunday and Monday still feature the highest rain chances, with higher odds of heavier rainfall along the Rio Grande and over the Edwards Plateau where 925- 850mb moisture transport is most enhanced. Despite the rainfall uncertainties, plentiful moist air means locally heavy downpours capable of producing flash flooding remain a possibility with stronger storm cells and clusters. The WPC has highlighted a marginal (level 1 of 4) risk for excessive rainfall over the entirety of South-Central Texas for Sunday through Monday morning. Daytime temperatures will be muted thanks to the clouds and rain, though they should still reach the upper 80s to low 90s as the post- frontal airmass warms. On Tuesday, upper ridging starts to restrengthen over Texas, bringing a return of drier conditions and a steady upward trend in daytime temperatures back into the mid 90s. && .AVIATION (12Z FRIDAY THROUGH SATURDAY)... Patches of MVFR CIGs have developed along and east of I-35. Have TEMPOs at those sites through 15Z. Otherwise, VFR flying conditions prevail today through this evening. Higher chances for MVFR CIGs tonight and have maintained as prevailing for all sites. S to SE winds prevail increasing to 7 to 12 KTs midday through evening. A front will bring VRBL winds at KDRT this evening into tonight with possible ISOLD SHRA/TSRA on the NW approaches to the site and to the I-35 sites on Saturday. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 75 89 72 89 / 10 30 20 60 Austin Bergstrom Intl Airport 75 90 72 90 / 10 30 20 60 New Braunfels Muni Airport 74 92 71 91 / 10 30 30 60 Burnet Muni Airport 72 82 69 84 / 10 40 20 60 Del Rio Intl Airport 78 93 74 89 / 20 60 40 70 Georgetown Muni Airport 73 85 70 87 / 20 30 20 60 Hondo Muni Airport 74 91 72 91 / 10 40 30 70 San Marcos Muni Airport 74 92 71 91 / 10 40 20 60 La Grange - Fayette Regional 74 91 72 90 / 10 40 20 60 San Antonio Intl Airport 76 91 74 91 / 10 40 30 60 Stinson Muni Airport 77 93 74 92 / 10 40 30 60 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Tran LONG TERM...Tran AVIATION...04