textproduct: Austin/San Antonio

KEY MESSAGES

Updated at 123 PM CDT Wed Aug 19 2026

- Heat Advisory in effect form the northern Hill Country, I-35 Corridor, and Coastal Plains Thursday-Sunday.

- August heat wave continues with no rain or heat relief in sight.

SHORT TERM

(Tonight through Thursday night) Issued at 123 PM CDT Wed Aug 19 2026

Regional satellite imagery clearly depicts the 500mb ridge centered over Arizona early this afternoon. The ridge itself is a bit more elongated from west to east, stretching over Texas. Underneath it, a weak tropical wave is moving inland over South Texas, but this will only send some mid to upper level cloud cover our way. Rain chances remain zero. Today will be yet another scorcher with highs ranging from 97 to 103, with heat indices higher in the Coastal Plains were mixing will be a bit lower.

On Thursday, we have opted to go with a Heat Advisory for Llano and Burnet, in addition to the I-35 Corridor and Coastal Plains. This advisory will stretch all the way through Sunday, and while temperatures should cool into the 70s for most at night, it's the rapid warm-up and steady rise in ambient air temperatures that makes things a bit more concerning from a safety aspect. Thursday won't be as hot as Friday-Sunday, but temperatures ranging from 100-104 are likely with heat indices climbing to 108-110 at times, particularly over the Coastal Plains. Once again, dry weather is expected with no rain chances in the forecast.

LONG TERM

(Friday through next Wednesday) Issued at 123 PM CDT Wed Aug 19 2026

The 500mb ridge steadily migrates eastward and by Friday/Saturday, it will be centered over the Texas Panhandle. At the 700mb level, the thermal ridge will be centered directly over Texas, so strong subsidence and sunny skies should be the normal through the weekend. Heat advisories will continue this weekend and actual air temperatures may approach warning levels (105+) for the Austin metro this weekend. Trends will be monitored for a possible upgrade to Extreme Heat Warning, but for now, expect highs in the 99-104 range for most locations through Sunday. Unfortunately, despite a brief lull and advisory level temperatures Monday-Tuesday, ridging will be in even greater control by mid to late next week, and highs in the 100-106 range look like a good bet. At this distance, little relief is in sight through the end of August, but a pattern change may be in the works as El Nino continues to strengthen over the Equatorial Pacific, which may result in increased rain chances in early to mid- September.

AVIATION

(18Z TAFS) Issued at 1219 PM CDT Wed Aug 19 2026

Under a strong ridge of high pressure skies will be mostly clear at all terminals for the next 24-30 hours. VFR conditions will prevail. Winds will be from the south around 10 kts with some higher gusts at times.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 78 103 78 104 / 0 0 0 0 Austin Bergstrom Intl Airport 77 103 77 103 / 0 0 0 0 New Braunfels Muni Airport 76 102 76 102 / 0 0 0 0 Burnet Muni Airport 75 101 75 101 / 0 0 0 0 Del Rio Intl Airport 78 102 78 102 / 0 0 0 0 Georgetown Muni Airport 78 102 78 102 / 0 0 0 0 Hondo Muni Airport 73 100 73 102 / 0 0 0 0 San Marcos Muni Airport 76 102 76 102 / 0 0 0 0 La Grange - Fayette Regional 77 103 77 103 / 0 0 0 0 San Antonio Intl Airport 78 102 77 102 / 0 0 0 0 Stinson Muni Airport 77 103 77 103 / 0 0 0 0

EWX WATCHES/WARNINGS/ADVISORIES

Heat Advisory from 2 PM Thursday to 7 PM CDT Sunday for TXZ171>173-191>194-205>209-220>225.