textproduct: Austin/San Antonio

KEY MESSAGES

Updated at 652 PM CDT Thu Sep 24 2026

- Drier with summer-like temperatures through the weekend.

- A Pacific cold front may bring widespread rain next week.

SHORT TERM

(Tonight through Friday night) Issued at 129 PM CDT Thu Sep 24 2026

Upper-air data from the DRT and FWD 12Z soundings show 500mb flow has become more southwesterly in response to amplified ridging centered over East Texas. Ridging is dominating the local weather pattern and will keep rain chances low and temperatures above-normal to end the week. Convective inhibition remains weak during the daytime, so a stray shower or two could still materialize this afternoon but with less coverage and likelihood than the past two days.

Highs Friday are forecast to reach the 90s. Northeasterly flow caused by an extension of surface high pressure across the lower Mississippi Valley will allow drier air aloft to mix down to the surface Friday afternoon particularly along and east of the Interstate 35 corridor. Thus, afternoon dew points are projected to bottom out in the 50s for some of these areas, helping to produce as close to a dry heat as we've had in quite some time. While this drier air will already be on its way out Friday night due to a restrengthening of southeasterly flow, lows north of Interstate 10 Friday night into Saturday morning especially in rural areas could be a few degrees lower than the usual fare we've seen, with wider coverage of lows closer to 70 and spots dipping into the upper 60s thanks to the fleeting dry air.

LONG TERM

(Saturday through next Thursday) Issued at 129 PM CDT Thu Sep 24 2026

An upper-level trough currently located over Baja California will cause the ridge over our region to shift towards South Texas this weekend. The 250mb ridge axis will still stay over our area, only pivoting rather than moving away completely, so temperatures will remain summerlike with rain chances staying low. The drier air from Friday will be replaced by more humid air over the weekend, causing heat indices to creep back up into the low 100s by early next week. Some weak filaments of vorticity are expected to glide along the northern periphery of the displaced ridge once it shifts far enough south. Low potential exists for this to produce some isolated showers or storms over the Edwards Plateau and Hill Country Sunday and Monday. These disturbances are weak, so subsidence from the nearby ridge will still tend to prevail and rain chances are 20% or less.

Sizable changes are afoot in the weather pattern next week. The major player in this changeup is a strong trough forecast to move across the western US early next week, with potential phasing of the polar and subtropical jet streams as it approaches our area. The strength of this trough will inject a plume of tropical Pacific moisture into the southwestern US. Ensemble trends over the past day have also increased the likelihood that moisture from Hurricane Polo in the Pacific will be incorporated in this spread of moisture. The primary uncertainty with this trough is timing, as its evolution over the southwestern US on Tuesday varies widely across models and is consequential to how quickly it advances into Texas mid to late next week. A faster trough may be able to bring deep tropical moisture farther east into South Central Texas, with increased potential for heavy rains around Wednesday. A slower trough could cycle out Polo's moisture to the west, which could reduce the rainfall potential for our area and delay the most favorable period for rains later to Friday. In the 00Z ensemble cluster analysis, the faster/slower trough scenarios were roughly evenly split between ensemble members. What models do agree on is that this will be a pronounced trough strong enough to clear out the ridge, bringing rain chances mid to late next week. The trough is also strong enough to bring the first noteworthy cold front of the season, which will likely be a focusing mechanism for the rain potential should it arrive. The national blend of models currently has the probability of highs being below 90F Wednesday and Thursday in the 50 to 70 percent range along and north of I-10. The timing of this front will also depend on the progression of the trough, though for now it looks the current window of arrival is between late Tuesday to early Friday based on the current ensembles.

It's a little too early to get into specifics regarding rain amounts. However, any pattern that involves the spread of deep Pacific moisture, with moisture contributions from a tropical cyclone, merits attention as a possible heavy rainmaker for South- Central Texas. For the time being, the main message is that the mid to late week period next week will likely bring a change in the weather pattern and the first opportunity for widespread rains this fall. Stay tuned to the forecast for further updates.

AVIATION

(00Z TAFS) Issued at 652 PM CDT Thu Sep 24 2026

A few showers persist across the region this evening and with only isolated coverage, we will not mention in the latest aviation forecasts. VFR will persist this evening into early Friday morning before low cloud development near SAT/SSF westward to DRT brings a period of MVFR cigs to the mentioned TAF sites. Conditions should be brief at SAT and SSF, so will continue with the TEMPO groups 12-15Z. Farther west at DRT, we will go with prevailing MVFR beginning 12Z, with cigs likely to persist through late morning.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 75 98 72 97 / 10 10 0 0 Austin Bergstrom Intl Airport 74 98 72 97 / 10 0 0 0 New Braunfels Muni Airport 73 97 72 95 / 10 10 10 0 Burnet Muni Airport 72 94 69 93 / 0 10 0 0 Del Rio Intl Airport 75 97 75 97 / 10 10 0 0 Georgetown Muni Airport 73 96 71 95 / 0 0 0 0 Hondo Muni Airport 73 95 72 94 / 10 0 0 0 San Marcos Muni Airport 73 98 71 96 / 10 10 10 0 La Grange - Fayette Regional 73 98 70 97 / 0 0 0 0 San Antonio Intl Airport 76 95 75 94 / 0 0 0 0 Stinson Muni Airport 76 96 74 95 / 10 0 0 0

EWX WATCHES/WARNINGS/ADVISORIES

None.