textproduct: Austin/San Antonio

KEY MESSAGES

Updated at 525 AM CDT Thu Sep 17 2026

- Low to medium rain chances for the coastal plains and I-35 corridor today, then less coverage through the first part of the weekend.

- Above average temperatures continue through the weekend.

SHORT TERM

(Today through Friday) Issued at 1200 AM CDT Thu Sep 17 2026

Upper level high centered between northeast Texas and the lower Mississippi Valley remains in that general area today and Friday. However, a low to mid level disturbance moving across the middle Texas coast into the local area in the afternoon is forecast to bring increased moisture and instability, resulting in slight to chances of rain. The areas with better probabilities are the coastal plains and I-35 corridor. Some activity could move over parts of the southern Edwards Plateau and Rio Grande plains early evening. Today's highs range from the mid to upper 90s and up to 101 degrees.

By Friday, the low to mid level disturbance moves between the Rio Grande and the Pecos area. A few showers are possible across the Rio Grande, otherwise, stays dry for the most part. Highs are forecast to reach the lower to upper 90s with a few locations getting into the 100 mark.

LONG TERM

(Friday night through Wednesday) Issued at 1200 AM CDT Thu Sep 17 2026

The upper ridge remains in control over the weekend with seabreeze type convection happening across the middle Texas coast. However, there is a good signal of increased moisture for Sunday afternoon across the coastal plains and therefore, isolated showers and storms are possible over some of these locations. Also, an upper level trough axis moving across the southern plains Sunday evening could bring isolated showers and storms across portions of the southern Edwards Plateau. From Monday through Wednesday, the local area stays between an upper level low to the west and another one to the right. This scenario could bring showers and storms each afternoon the coastal plains and portions of the southern Edwards Plateau. There is a lot of uncertainty for next week.

AVIATION

(12Z TAFS) Issued at 525 AM CDT Thu Sep 17 2026

A weak mid level disturbance over South TX today will bring a slight uptick in rain chances along the I-35 corridor this afternoon and evening. Enough activity is suggested that a PROB30 group for just the I-35 sites for a few hours of the late afternoon mainly to account for the potential seabreeze/outflows impact on those sites. Extra time periods were added to better track the winds that could gust over 25 knots near the seabreeze for a few hours. Then a period of stable air and shifting winds finish out the evening with more SCT V BKN conditions for Friday morning.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 100 76 99 73 / 10 10 0 0 Austin Bergstrom Intl Airport 99 75 99 72 / 20 10 0 0 New Braunfels Muni Airport 98 74 98 71 / 20 10 10 0 Burnet Muni Airport 96 73 96 70 / 10 10 0 0 Del Rio Intl Airport 99 77 97 76 / 0 20 10 0 Georgetown Muni Airport 99 75 98 72 / 10 10 0 0 Hondo Muni Airport 98 74 97 72 / 20 20 10 0 San Marcos Muni Airport 99 73 99 71 / 20 10 0 0 La Grange - Fayette Regional 97 74 98 71 / 30 10 0 0 San Antonio Intl Airport 98 77 97 74 / 20 20 10 0 Stinson Muni Airport 99 76 99 73 / 20 20 10 0

EWX WATCHES/WARNINGS/ADVISORIES

None.