textproduct: Austin/San Antonio

KEY MESSAGES

Updated at 1200 AM CDT Sat Sep 12 2026

- Heat Advisory in effect Saturday from Noon until 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.

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

SHORT TERM

(Today through Sunday) Issued at 1200 AM CDT Sat Sep 12 2026

Mid and upper level high pressure will build in from the west today. This will allow for an area of mid-level subsidence currently over much of the northern portion of Texas to drop southward into our region. This subsidence should limit the chance for convection on Saturday and while the NBM pops are very low, we have opted to add a mention of afternoon showers and storms for portions of the coastal plains into the Highway 77 corridor. At least a few of the hi-res models hint at some late afternoon convection developing. We will need to monitor areas farther north into the I-35 corridor and Hill Country for a possible mention of thunderstorms. However, confidence in this is low for now and will keep out of the forecast today.

Temperatures on Saturday look to be the hottest of the forecast period with highs in the upper 90s to near 106 degrees. The NBM numbers looked too low, so we opted to bump forecast highs over the NBM for today and Sunday. While temperatures may ease slightly, we could see some peak heat index values close to Advisory level on Sunday, mainly east of the I-35 corridor into the coastal plains.

LONG TERM

(Sunday night through Friday) Issued at 1200 AM CDT Sat Sep 12 2026

Mid and upper level high pressure will be the dominant weather feature through much of the upcoming week. A large area of high pressure sets up over the southeastern U.S. and eventually expands westward into the northern and western Gulf. This pattern is expected to keep our forecast mostly dry along with above normal temperatures. Some late afternoon convection will remain in the forecast for the coastal plains region. Temperatures for much of the upcoming week will continue to remain above normal with highs in the mid 90s to lower 100s and lows in the 70s.

AVIATION

(06Z TAFS) Issued at 1238 AM CDT Sat Sep 12 2026

Some residual high clouds will continue to slowly dissipate leaving a better environment for some low clouds to form. We continue to leave the clouds as SCT, but will probably switch to a few hours of BKN CIGs in the 09Z updates for AUS/SAT. Less convection is forecast for today and is not mentioned in any of our TAFS. More diurnal wind trends will continue with daytime southerlies mostly around 10 knots or less and some gusty SE breezes could reach 25 knots in the early evening over I-35

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 104 77 102 77 / 0 0 0 0 Austin Bergstrom Intl Airport 104 77 100 76 / 0 0 0 0 New Braunfels Muni Airport 102 76 100 75 / 0 0 0 10 Burnet Muni Airport 99 74 98 74 / 0 0 0 0 Del Rio Intl Airport 104 79 102 78 / 0 0 0 10 Georgetown Muni Airport 102 77 100 76 / 0 0 0 0 Hondo Muni Airport 102 75 99 75 / 0 0 0 0 San Marcos Muni Airport 102 75 100 75 / 0 0 0 0 La Grange - Fayette Regional 101 77 99 76 / 20 20 20 0 San Antonio Intl Airport 102 78 100 78 / 0 0 0 10 Stinson Muni Airport 103 79 102 77 / 0 0 0 10

EWX WATCHES/WARNINGS/ADVISORIES

Heat Advisory from noon today to 7 PM CDT this evening for TXZ173-191>194-205>209-220>225.