textproduct: Austin/San Antonio

KEY MESSAGES

- A line of storms is forecast to move from the southern Edwards Plateau into the Hill Country tonight, with heavy downpours and isolated severe weather possible.

- The line of thunderstorms will move across the I-35 Corridor and into the Coastal Plains early Sunday.

- The potential for strong to severe storms and locally heavy rainfall continues through the weekend into early next week.

SHORT TERM

(Tonight through Sunday night) Issued at 121 PM CDT Sat Apr 11 2026

An upper level low off the west coast anchors a deep trough along the coast with southwesterly flow across northern Mexico into TX. The low level flow is from the southeast across our CWA. The airmass over South-Central Texas remains warm and moist. Temperatures are in the 70s and dewpoints in the middle to upper 60s. A shortwave trough is moving through the pattern across northern Mexico toward TX. This shortwave will provide lift to generate thunderstorms later this afternoon and evening. Forecast soundings show modest CAPE and shear which should be sufficient for strong to severe thunderstorms into the evening over our Southern Edwards Plateau region. Hi-res models suggest a line of thunderstorms moving from West TX into our CWA tonight which could bring severe storms overnight. Steep lapse rates suggest large hail as the main threat with damaging winds also likely. There is a lower threat for tornadoes. The line of storms will progress across the Hill Country and I-35 Corridor Sunday morning and early afternoon. At the same time the upper low will move onto the west coast sending another shortwave trough across TX. Convection Sunday afternoon and evening will be dependent on how much cloudiness restricts heating. Regardless of when storms form models show sufficient instability and shear to generate strong to severe storms. Again hail and winds are the main threats with tornadoes also possible.

With the high dewpoints and moist air aloft, PW values will be well above normal through the period. Thunderstorms will produce locally heavy rain that could lead to flash flooding. The flooding threat will follow the storms from west to east. For tonight the main threat area will be the Southern Edwards Plateau into the western Hill Country. It will move into the eastern Hill Country and I-35 Corridor Sunday morning.

LONG TERM

(Monday through next Saturday) Issued at 121 PM CDT Sat Apr 11 2026

The upper trough will move slowly across the western states Monday through Wednesday. This will keep TX in southwesterly flow aloft. Low level flow will continue from the southeast keeping a warm, moist airmass in place. This will mean continuing chances for showers and thunderstorms each day into the middle of next week. Timing will likely be afternoon and early evening. Without much change in the pattern, strong storms with locally heavy rainfall are looking possible each day. The movement of the upper trough may keep the worst weather farther north, but it's too soon to get specific on details. Best to be prepared for multiple days of significant weather.

AVIATION

(18Z TAFS) Issued at 121 PM CDT Sat Apr 11 2026

Cigs have nudged upward to VFR or will shortly along the I-35 corridor as scattered showers continue this afternoon. We will keep the mention of PROB30 groups for TSRA for the I-35 sites between 20- 23Z. More shower activity is possible overnight as cigs drop to MVFR 03-04Z, then IFR after 08Z. Will continue to monitor the early morning hours as a line of storms moves in from the west. For now, will include a mention of PROB30 along the I-35 sites, but could easily bump this upward to a TEMPO group in subsequent forecasts. Out west at DRT, MVFR will linger for another 1-2 hours, then trend back to VFR. Convection here appears most favorable during the late evening into the very early morning hours as storms move in from the west.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 68 79 69 86 / 60 80 50 20 Austin Bergstrom Intl Airport 68 78 69 85 / 50 80 50 20 New Braunfels Muni Airport 68 79 68 86 / 50 80 50 20 Burnet Muni Airport 66 77 67 83 / 70 80 40 20 Del Rio Intl Airport 68 85 69 87 / 90 40 20 20 Georgetown Muni Airport 68 77 68 83 / 60 80 50 20 Hondo Muni Airport 66 80 67 85 / 60 80 40 20 San Marcos Muni Airport 68 79 69 85 / 50 80 50 20 La Grange - Fayette Regional 69 80 69 86 / 30 70 50 20 San Antonio Intl Airport 68 79 69 85 / 60 80 50 20 Stinson Muni Airport 71 80 70 86 / 50 80 50 20

EWX WATCHES/WARNINGS/ADVISORIES

None.