textproduct: Austin/San Antonio

KEY MESSAGES

- Very warm and humid with elevated heat indices from today into tonight.

- A pair of cold fronts to bring increased rain and storm chances mid to late week and cooler temperatures.

- Isolated strong to severe storms and locally heavy rain remains possible in the days ahead; strongest signal for rainfall occurs early Friday.

- Drier this weekend with temperatures slowly warming back up into early next week.

SHORT TERM

(Tonight through Wednesday night) Issued at 1246 PM CDT Tue Apr 28 2026

Overachieving cap and hazy inversion likely from agricultural smoke influx from the south continues to limit storm potential and will probably lead to zero or one thunderstorm in our forecast area tonight. Counties that might see a stray storm would include Val Verde, Llano, Burnet, and Williamson with no precipitation expected for the rest of the area. Warm and humid conditions will lead to potentially another record high minimum day for DRT and SAT, but AUS/ATT should get better cooling from the front that arrives into northern counties around daybreak. This frontal arrival will also signal the arrival of more significant rain chances that will expand southward with the front during the day.

A marginal risk for severe storms will be in play with large hail and damaging winds being the primary threat. And since most of the higher res models show little to no storm activity forming along the front, the tornado threat should be very low. CAPE values behind the front will come down to typical levels after dangerously high values have been observed the past couple days. Best rain chances are depicted well behind the front, and most of the higher res models show best QPF holding along and north of Highway 90, that doesn't mean a slow moving heavy downpour can't pop up over the southern counties where the front comes to a crawl. Rain chances carry over into nighttime, but will probably drop in coverage to more 20 to 40 percent.

LONG TERM

(Thursday through next Tuesday) Issued at 1246 PM CDT Tue Apr 28 2026

As we get into daytime Thursday, the weak zonal shortwaves driving convection will be replaced with a more synoptic scale upper low, leading to better and more broadly distributed rain chances. Still the better rain chances hug to the northern CWA at least initially. By 00Z Friday the chances become more broad with most counties getting a likely category for Thursday night into noon Friday. High rain chances and storm intensities continue into Friday afternoon, but start shifting eastward as a second cold front begins bringing drier air into the region. While each day, storms are capable of dropping 1-3 inches, storm totals will probably not be too concentrated on a specific area given a broad pattern for ascent and overrunning. If I were to guess, the higher end storm total amounts might reach around 5 inches by Friday afternoon. This means localized flooding is anticipated at some point during the 3-day event. With models trending slightly faster, the rain chances for Friday night should probably decrease over time based on what the latest deterministic runs are showing.

Weekend cooling will bring northern counties down into the 40s each morning, with area-wide highs in the 70s. This type of cooling may be the last one we get this spring, although there is a signal for another deep upper trough shown about 10 days out. The warming trend early next week should be gradual again as the pattern aloft stays mostly flat through midweek.

AVIATION

(00Z TAFS) Issued at 640 PM CDT Tue Apr 28 2026

A small cluster of TSRA northwest of KDRT may near the terminal around 02Z-03Z but should dissipate by 04Z. MVFR/IFR CIGs are expected return to KAUS/KSAT/KSSF tonight, with higher confidence at KSAT. Satellite images show HZ continuing to move into the region, so periods of slightly reduced VSBYs and slant range VSBYs could continue through the morning as southerly flow continues. A front should slowly sag over the region most likely after 15Z, which will clear up the HZ. There is significant uncertainty with precise timing of the front, to be ironed out in later TAFs, but a 6-12 kt north to northeasterly wind should follow behind the front. Scattered SHRA/TSRA is possible behind the front, with enough support in hi-res models to include mention in PROB30s at KAUS and KSAT

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 72 86 66 80 / 10 40 40 40 Austin Bergstrom Intl Airport 73 87 67 81 / 10 40 40 40 New Braunfels Muni Airport 73 88 66 83 / 10 30 30 30 Burnet Muni Airport 69 79 63 75 / 20 50 40 50 Del Rio Intl Airport 76 95 71 84 / 10 30 40 30 Georgetown Muni Airport 71 82 65 76 / 20 50 40 40 Hondo Muni Airport 72 92 68 84 / 10 30 30 20 San Marcos Muni Airport 73 89 66 82 / 10 40 30 30 La Grange - Fayette Regional 74 90 68 84 / 10 40 30 30 San Antonio Intl Airport 74 90 68 84 / 10 30 30 30 Stinson Muni Airport 74 92 69 85 / 10 30 20 20

EWX WATCHES/WARNINGS/ADVISORIES

None.