Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX
Issued by NWS Austin/San Antonio, TX
577 FXUS64 KEWX 241741 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 1241 PM CDT Sun Aug 24 2025 .KEY MESSAGES... - Daily chances of showers and thunderstorms through next week with slightly higher chances Tuesday/Wednesday and over the weekend. - Temperatures within a few degrees of seasonal averages to close out August. && .SHORT TERM (THROUGH MONDAY NIGHT)... Water vapor and ALPW imagery shows some drier mid-level continental air has wedged into South-Central Texas along the southeastern periphery of a mid-level ridge centered over New Mexico. The shear axis responsible for the isolated to scattered storms over the past few days has also dropped farther south and our area. This will keep most dry and help limit shower development. That said, the combination of easterly winds this afternoon and temperatures rising into the upper 90s supports a chance (10 to 20 percent) for some sparse popup showers and an isolated storm over the Coastal Plains to the Winter Garden area and near the I-35 corridor from the late afternoon to the evening. Late morning and early afternoon cumulus development so far today has slightly overperformed models, so shower coverage may be higher than depicted in the hi-res CAMs. Still, instability and deep- layer moisture are noticeably lower than in recent days, so showers and storms are expected to remain fairly subdued. The mid-level ridge becomes more centered over our area Monday, leading to a return of more typical southerly and southeasterly winds. This will keep most of the area dry, though a few coastal showers could work their way into the Rio Grande Plains and the lower Coastal Plains with the seabreeze. Similarly seasonable warm temperatures are forecast Monday afternoon, with highs in the low to mid 90s in the Hill Country and mid to upper 90s for the rest of South-Central Texas. && .LONG TERM (TUESDAY THROUGH SUNDAY)... The ridge remains over South-Central Texas through the week. However, a shortwave embedded in a stout mid-level trough will be sweep across the Ohio River Valley Monday into Tuesday. The high pressure area that develops over the Mississippi River Valley rearward of this trough will help slip a front beneath the ridge and into Texas beginning Tuesday. The front slows over Texas and eventually retreats north and washes out by Thursday, giving a Tuesday to Wednesday window where the front could be draped at least partially over our area. Moisture convergence will help to enhance rain chances along the front, but the ridge being overhead limits the availability of mid-level moisture and maintains synoptic-scale subsidence that acts to limit the extent of those rains. If the front stays north of our area, it is possible that most of the rain will originate from the seabreeze being enhanced by the tightened pressure gradient south of the front rather than rains straddling the front itself, and the medium-range guidance indicates this may be the more likely outcome. This would favor rains over the Coastal Plains to the I-35 corridor. Altogether, competing factors for shower development and lack of clarity in frontal positioning leads to low confidence in placement and coverage of rain chances during the midweek period, with PoPs of 30 to 40 percent along the Coastal Plains and 15 to 30 percent elsewhere. Increased cloudiness and rain chances Tuesday and Wednesday should keep high temperatures slightly down, with more widespread low to mid 90s. After the front retreats Thursday, rain chances decrease and temperatures rise back into the mid to upper 90s. Both the GEFS and EPS ensembles indicate anomalous troughing continuing over the eastern half of the CONUS. This leaves the door open for weak frontal boundaries making their way into our area depending on the orientation and placement of the troughing and the subtropical ridge. Ample disagreement is seen in the models for the weekend, though both the CMC and ECMWF models indicate a front similar to the midweek front could slide south near or over our area over the weekend, bringing another opportunity for rain as early as Friday and continuing into the weekend depending on the frontal timing. && .AVIATION (18Z SUNDAY THROUGH TUESDAY)... VFR flight conditions prevail through the TAF period with a late morning through early evening scattered cumulus field. Convective allowing models have been indicted isolated SHRA/TSRA activity developing 20Z-00Z near and east of the I-35 corridor today, then dissipating after sunset. Currently chances are too low (10%) to include at SAT/SSF/AUS TAFs. We will monitor trends through the afternoon for possible amendments. This isolated SHRA/TSRA activity will be capable of producing gusty winds in excess of 30KT. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 75 98 74 97 / 0 0 0 20 Austin Bergstrom Intl Airport 74 98 73 96 / 0 0 0 20 New Braunfels Muni Airport 72 98 72 96 / 0 0 0 20 Burnet Muni Airport 73 94 72 93 / 0 0 0 20 Del Rio Intl Airport 76 98 77 97 / 0 0 10 20 Georgetown Muni Airport 73 97 72 96 / 0 0 0 20 Hondo Muni Airport 72 97 72 96 / 0 0 10 20 San Marcos Muni Airport 73 99 72 97 / 0 0 0 20 La Grange - Fayette Regional 73 96 72 95 / 0 0 0 30 San Antonio Intl Airport 76 98 75 96 / 0 0 0 20 Stinson Muni Airport 76 100 76 97 / 10 0 0 30 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...Tran Long-Term...Tran Aviation...76