textproduct: Austin/San Antonio

KEY MESSAGES

Updated at 622 PM CDT Sat Sep 12 2026

- Heat Advisory in effect through 7 PM for areas generally along and east of the Interstate 35 corridor. Above normal temperatures will persist into early next week, with additional heat headlines possible.

- Low chance (15 percent) for isolated thunderstorms this afternoon and evening from the Hill Country east.

- Most areas remain dry into next week, except for some low rain chances over the coastal plains.

SHORT TERM

(Tonight through Sunday night) Issued at 1252 PM CDT Sat Sep 12 2026

Lingering cloud cover over the portions of the I-35 corridor and coastal plains provided a "cooler" start to the day than seen yesterday, though temperatures are still expected to climb into the upper 90s and triple digits later this afternoon. Highs were lowered about a degree over the I-35 corridor but we are still expecting heat index values to rise into the 108-111 degree range for a good portion of the Heat Advisory area which remains in effect through 7 PM.

Ridging continues to build over the area today from the west which will limit the coverage of storm development this afternoon and evening. That said, hi-res guidance continues to indicate at least a few isolated showers or thunderstorms today aided by peak heating. If a few storms develop, the main focus will be from the Hill Country and locations to the east. Have capped the PoPs at 15 percent due to the isolated nature of any activity.

The elongated ridge will be over North Texas Sunday keeping rain chances low again (mainly limited to the coastal plains) and temperatures hot. Highs should decrease slightly for tomorrow but no hover near Heat Advisory levels. With more sparse coverage for Heat Advisory conditions expected at this time, have held off on any product issuance for Sunday but we will continue to monitor for the I-35 corridor and coastal plains.

LONG TERM

(Monday through next Saturday) Issued at 1252 PM CDT Sat Sep 12 2026

Above normal temperatures persist next week. An upper level ridge will be centered northeast of our area Monday through at least the middle of next week, eventually expanding further west late week. Highs will continue to range from the mid 90s to slightly above 100 degrees each day through mid-week with heat indices hovering around the 105-108 degree mark near the I-35 corridor and coastal plains. Some seabreeze showers and thunderstorms may impact the coastal plains each afternoon/evening, otherwise expect mainly dry conditions. The forecast does bring a slight decrease in temperatures (at least staying below 100 degrees) late week along with some better coverage of rain chances, but there remains decent uncertainty in the pattern this far out.

AVIATION

(00Z TAFS) Issued at 622 PM CDT Sat Sep 12 2026

A shower could linger near KAUS for the next hour or two before any remaining activity dissipates for the night. Partly cloudy to mostly clear skies trend from this evening into the overnight before increasing low clouds develop from early to mid-morning Sunday. This would result in prevailing MVFR ceilings at the San Antonio terminals (KSAT and KSSF) and the temporary potential across KAUS and KDRT. KDRT will be after sunrise for when this potential exists. Sunday will otherwise see VFR flight conditions return with few to sct mid-level cumulus. Isolated showers or a storm may again be possible on Sunday afternoon but looks to generally favor locations along and east of the I-35 corridor. South-southeasterly winds could be moderately breezy this evening with gusts up to 25 kt before subsiding from the overnight into early Sunday morning. Speeds then uptick slightly from mid to late morning into the afternoon.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 78 101 78 100 / 20 10 0 0 Austin Bergstrom Intl Airport 77 100 77 99 / 20 10 0 10 New Braunfels Muni Airport 76 100 76 99 / 20 10 0 10 Burnet Muni Airport 75 97 74 97 / 20 10 0 0 Del Rio Intl Airport 79 101 77 100 / 0 0 0 0 Georgetown Muni Airport 77 100 77 99 / 20 10 0 0 Hondo Muni Airport 75 100 75 99 / 20 10 0 0 San Marcos Muni Airport 76 100 76 99 / 20 10 10 10 La Grange - Fayette Regional 77 100 77 99 / 20 20 0 30 San Antonio Intl Airport 78 99 78 99 / 20 10 0 10 Stinson Muni Airport 78 101 78 100 / 20 10 0 10

EWX WATCHES/WARNINGS/ADVISORIES

Heat Advisory until 7 PM CDT this evening for TXZ173-191>194- 205>209-220>225.