textproduct: Austin/San Antonio

KEY MESSAGES

Updated at 545 AM CDT Tue Aug 25 2026

- Heat Advisory continues through Wednesday for the Coastal Plains, I-35 corridor, and portions of the Hill Country.

- Low to medium rain and storm chances for most areas Thursday and Friday. Otherwise, hot and dry weather throughout the week.

SHORT TERM

(Today through Wednesday) Issued at 1210 AM CDT Tue Aug 25 2026

A Heat Advisory remains in effect through Wednesday for portions of the Hill Country and most areas along and east of I-35 as temperatures remain high throughout the region. A subtle shift of the hottest air westward, along with the subtropical ridge, favors a more southeasterly wind direction that helps lower highs through Wednesday, but only by a few degrees. The takeaway is still that highs above 100F will remain widespread across South Central Texas Tuesday and Wednesday with the hottest spots within the Heat Advisory area nearing 105F. A few isolated spots could still briefly rise above 105F in low lying valleys.

Conditions will remain dry in the short term with the ridge staying overhead. A weak mid-level shortwave closer to the Red River late Tuesday should spill scattered upper-level cirrus our way. There is a low potential for rain from that disturbance on Wednesday, mainly dependent on the placement of an outflow boundary from activity farther north. Chances are generally at or below 20 percent and limited to the northern Hill Country at this time. Otherwise, the high clouds may provide slight radiative relief from the afternoon sun.

LONG TERM

(Wednesday night through Monday) Issued at 1210 AM CDT Tue Aug 25 2026

The overall tendency for ridging to shift farther west Thursday and Friday, allowing a northwesterly flow to set up aloft, remains evident across the models. This has the benefit of both shifting the warmest portion of the summertime airmass away from our area, and also providing an avenue for weak areas of vorticity to round the ridge and skirt South Central Texas, bringing some potential for showers and thunderstorms. This looks most favored Thursday, when the Z700 flow becomes northwesterly as a shortwave trough approaches. Rain chances Thursday are low to medium, from about 20 to 50 percent. Rain chances could continue into Friday if this energy sticks around and enough surface heating occurs beneath the slight mid-level baroclinicity, bringing another shot of isolated shower and storm activity Friday afternoon. Given the broader environment, any convection that develops will probably be high- based with the strongest cells providing a threat for gusty winds and lightning. The likelihood for rain is expected to decrease from north to south. The aforementioned displacement in the hottest air and opportunities for cloud cover favor highs in the latter half of the week lowering slightly below advisory criteria, though it would not take much of a downtrend in rain chances to keep temperatures as hot as they've been. Additionally, higher dew points could keep heat indices comparably hot regardless of variations in the ambient temperature.

Over the weekend, becomes a little more diffuse and broadens, resulting in a less favorable flow aloft for dynamically supported convection. This will bring rain chances down with drier conditions expected to prevail, though the slightly weaker strength of the ridge implies that a few isolated seabreeze showers could break through on occasion in the Coastal Plains. Temperatures remain hot and will likely continue to straddle 100F for highs into early next week.

AVIATION

(12Z TAFS) Issued at 545 AM CDT Tue Aug 25 2026

VFR flight conditions continue. Patchy low clouds have developed well east-northeast of the I-35 corridor so far for early this morning. Otherwise, a few passing high level clouds are currently advancing across the region. Winds trend the lightest early to mid-morning with directions from the south-southwest at the I-35 terminals and easterly at KDRT. The afternoon will see a slight uptick in the winds from the southeast before the strongest winds occur after sunset as the sea breeze moves through. This will be when the gusts could reach as high as 20 to 25 kts for a period of time. Some morning low clouds may establish into Wednesday morning but again the area east of the I-35 corridor is most favored for this development.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 104 78 104 79 / 0 0 0 10 Austin Bergstrom Intl Airport 103 76 103 77 / 0 0 0 10 New Braunfels Muni Airport 103 75 103 76 / 0 0 0 10 Burnet Muni Airport 102 76 102 76 / 0 0 10 10 Del Rio Intl Airport 104 79 105 79 / 0 0 0 0 Georgetown Muni Airport 103 78 103 77 / 0 0 10 10 Hondo Muni Airport 102 74 102 76 / 0 0 0 0 San Marcos Muni Airport 103 75 103 76 / 0 0 0 10 La Grange - Fayette Regional 103 77 103 78 / 0 0 0 10 San Antonio Intl Airport 102 78 103 79 / 0 0 0 0 Stinson Muni Airport 104 76 104 78 / 0 0 0 0

EWX WATCHES/WARNINGS/ADVISORIES

Heat Advisory until 7 PM CDT Wednesday for TXZ171>173-191>194- 205>209-220>225.