textproduct: Austin/San Antonio

KEY MESSAGES

Updated at 642 PM CDT Mon Sep 21 2026

- Low to medium chances for isolated showers and storms continues into Tuesday.

- Unseasonable hot conditions continue with some reprieve in the humidity levels by next weekend.

SHORT TERM

(Tonight through Tuesday night) Issued at 1211 PM CDT Mon Sep 21 2026

A stationary frontal boundary is located over northern TX with our area under an elongated flattened ridge. The ridge isnt particularly strong so we could see another round of isolated showers and storms across the area particularly across the Hill Country into the I-35 Corridor this afternoon into this evening. We shouldn't see much in the way of severe weather as shear remains very low. DCAPE values could get above 1000 J/kg which would continue to support strong gusty winds in any of the stronger storms that develop. This front will continue to linger northward of the area tomorrow as the mid level ridge over us begins to restrengthen. Chances for showers and storms should be lower but not zero as the ridge begins to suppress instability across the area.

Regarding temperatures we should see another unseasonably hot day for south central TX with almost everyone getting into the mid to upper 90s which is well above normal for this time of year. While records are possible, they seem to be just out of reach for today as we are not expecting triple digit heat. It will however remain very humid with PWATS currently in the 1.5 to 1.9 inch range which is well above normal for this time of year. When adding in the humidity with the heat we will expect to see another day of heat indices in the 101 to 107 degree range which should keep us just shy of heat advisory criteria. Tuesday we should see very similar highs with just a tad bit less humidity as the ridge of high pressure starts to strengthen. Similarly heat indices should also be slightly lower and more in the 100-105 degree range. Nights however will continue to remain very warm for this time of year, in the low to mid 70s.

LONG TERM

(Wednesday through next Monday) Issued at 1211 PM CDT Mon Sep 21 2026

Several global models indicate the mid level ridge continuing to strengthen during the long term thus reducing our chances for rain and storms. It eventually pushes off to the east across the TX/LA border by the end of the week before meandering back west southwestward over our area over the weekend. The result is most areas should remain dry with just very spotty isolated showers and thunderstorms across the Coastal Plains and again across the Rio Grande as they remain on the periphery of the ridge. The good news is that with the ridge being close by it should drop our humidity values beginning Thursday as onshore flow from the Gulf will be reduced. While it will remain unseasonably hot across the area, heat indices will only likely be 1 to 3 degrees above the actual air temperatures giving us some reprieve from the oppressive heat and humidity we have experienced for most of this month. Unfortunately rain chances continue to look abysmal for most of the area as long as the ridge remains parked nearby.

AVIATION

(00Z TAFS) Issued at 642 PM CDT Mon Sep 21 2026

There are still a few showers and thunderstorms around the area and they will continue for a few more hours. There is a low chance for a storm to move across the airports in Austin and San Antonio this evening. Any storm could produce wind gusts up to 25 kts. Otherwise all terminals will be VFR through the evening and overnight. MVFR ceilings will develop in the San Antonio area Tuesday morning, but only last a few hours.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 75 100 76 100 / 20 20 30 10 Austin Bergstrom Intl Airport 75 99 76 99 / 20 20 20 10 New Braunfels Muni Airport 74 98 74 98 / 20 10 30 0 Burnet Muni Airport 72 94 73 95 / 20 40 10 10 Del Rio Intl Airport 76 97 74 97 / 10 10 40 0 Georgetown Muni Airport 74 97 75 98 / 30 20 20 10 Hondo Muni Airport 73 95 73 95 / 20 10 10 0 San Marcos Muni Airport 73 99 74 99 / 20 10 20 0 La Grange - Fayette Regional 75 99 75 99 / 10 10 10 10 San Antonio Intl Airport 76 96 77 96 / 20 10 20 0 Stinson Muni Airport 75 96 76 96 / 20 10 20 10

EWX WATCHES/WARNINGS/ADVISORIES

None.