textproduct: Austin/San Antonio

KEY MESSAGES

- Isolated strong to severe storms possible west of the I-35 Corridor overnight.

- Chance for isolated storms Wednesday mainly north of Highway 90; a near widespread chance of rain and storms Saturday from a cold front.

- Warm and humid conditions through Friday, then cooler than normal this weekend into Monday.

SHORT TERM

(Today through Thursday) Issued at 1239 AM CDT Wed Apr 15 2026

A rude beginning to the overnight forecast package came with severe storms that slightly overachieved their timing and a very untimely KDFX radar crash with a severe storm bearing down on top of Del Rio. The steady but unstable SW flow aloft will continue to supply dynamics and Pacific moisture to keep this activity going through at least 2 AM, but most of the HREF solutions diminish this activity between 2 and 5 AM. Long lived elevated showers left behind dissipated storms are a good sign that PWat values are quite elevated, and the HRRR confirms this with up to 1.75 at around DRT in one of the more recent runs. With the near midnight observation of heavy lightning and storms that are starting to train a bit, we could see some flash flooding take place before we able to get the storm trends in the right direction.

With the slight over achievement of convection and another round expected to light up over the Hill Country for Wednesday, we may need to review the rain chances for the daytime and possibly expand higher chances farther south than what is out there currently. But for now we'll stick to the blends and hope the consensus is correct on the lower coverages. With the type of storms we are getting and the amount of training occurring, localized flooding is a possibility, and not having a radar to cover the western areas that already got some heavy rain could be a bit nerve-racking.

Later in the evening, the cap is assumed to have strengthened as coverage wains somewhat early in the nigh as compared to what we're seeing tonight. This is also shown in the high temperature forecast for Thursday that is expected to perk up about 5 degrees over what's expected for Wednesday. No rain is currently forecast for Thursday but there are expected to be some dry-line storms just northwest of our CWA Thursday evening.

LONG TERM

(Thursday night through Tuesday) Issued at 1239 AM CDT Wed Apr 15 2026

Friday, persistence weather is expected as the weak ridging pattern over the area is similar to that of Thursday. Breezy, warm and humid conditions will give way to another day of highs in the 80s to mid 90s. Friday night, the pattern destabilizes from another low latitude upper trough into the SW CONUS, setting up more unstable SW flow aloft over TX. Initially the storms will stick to the western counties as they have been tonight, but a cold front arriving Saturday will bring what could be a widespread rain event with most of the falling rain overrunning behind the front. The leading edge storms could be strong as one might expect in April, but we think most of the post frontal activity should be better behaved as the frontal layer to arrive is apparently going to be quite a bit deeper than our more recent fronts. Plus the cold front is set to arrive fairly early in the day. Besides having the strong front cooling us off for a late spring treat, we also should benefit from a favorable pattern of continued overrunning which might help us on the rain deficit problem.

AVIATION

(06Z TAFS) Issued at 1239 AM CDT Wed Apr 15 2026

MVFR cigs are forecast for the I-35 sites through about noon/17Z. A cluster of storms could move across KDRT between 06z and 07Z to bring lower cigs and vbsys to 3SM in addition wind gusts up to 35 knots assuming the storms move over the terminal. Otherwise, MVFR cigs are forecast overnight through late Wednesday morning. There is a time window around 12Z where IFR cigs could happen, but there is low confidence with that. VFR conditions return around noon at the I-35 sites and a few hours later for KDRT. Southeasterly to south winds 8 to 14 knots with gusts up to 25 knots are forecast for all area sites throughout the day and early evening.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 85 69 89 69 / 40 30 0 0 Austin Bergstrom Intl Airport 86 68 90 69 / 30 30 0 0 New Braunfels Muni Airport 85 67 89 69 / 30 20 0 0 Burnet Muni Airport 81 66 85 67 / 50 30 10 0 Del Rio Intl Airport 85 69 90 70 / 20 10 10 0 Georgetown Muni Airport 83 67 87 68 / 40 40 0 0 Hondo Muni Airport 83 65 89 66 / 40 10 0 0 San Marcos Muni Airport 85 67 89 69 / 30 30 0 0 La Grange - Fayette Regional 86 69 89 69 / 10 10 0 0 San Antonio Intl Airport 85 69 89 70 / 30 20 0 0 Stinson Muni Airport 86 70 90 70 / 20 10 0 0

EWX WATCHES/WARNINGS/ADVISORIES

None.