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 Friday.

- Dries out this weekend with temperatures gradually warming back up into early next week.

SHORT TERM

(Today through Wednesday) Issued at 123 AM CDT Tue Apr 28 2026

There will be a low chance for a storm across the Southern Edwards Plateau beyond midnight due to a slight pocket of 700 mb moisture approaching from Terrell County. If a storm does establish, I couldn't rule it out from becoming briefly strong to severe before dissipating. Elsewhere, conditions into Tuesday morning remain rain free with increasing low clouds. Like the last few days, the low clouds could be pesky and linger at least into early afternoon before scattering out. The NBM guidance during the last several days has been a bit too low regarding the area dew points. This has resulted in the model decreasing cloud cover too much and too quickly the last several days, which has resulted in the NBM overforecasting afternoon highs by a few degrees and the overnight lows too low by a couple degrees as well. While today remains the warmest day, I'll make adjustments based on these observations the last few days and this may keep the elevated heat indices a little farther away from Heat Advisory criteria than previous forecasts, with most topping out in the 99 to 104 range. Expect the highest heat indices to around 108 in the Rio Grande Plains.

Conditions are expected to stay mostly rain free through at least the first half of Tuesday night as models indicate that the capping inversion remains stout across the region due to the lack of any substantial forcing. A few storms are again likely to develop over the Burro Mountains of Mexico but are likely to diminish before reaching the Rio Grande this evening. With today being the warmest day of the week, we'll still closely keep an eye on the capping inversion, in case the differential heating does weaken it.

Next, we'll monitor for any potential outflow that could approach the region entering early Wednesday morning from storms over North Texas, that could develop late tonight, with an approaching front coming out of Oklahoma. We then expect for this front to advance southward into our region through the day on Wednesday. The front should finally provide enough forcing to erode the cap and provide scattered showers and storms across the region. Enough instability and bulk shear will be in place to allow for isolated strong to severe storms and locally heavy rainfall. We'll also see relief behind this front with the arrival of some cooler air, which would also be reinforced by rain cooling processes and cloud cover.

LONG TERM

(Wednesday night through Monday) Issued at 123 AM CDT Tue Apr 28 2026

The front lingers near or just south of the region into and during the day on Thursday. This will keep isolated to scattered showers and storms in the forecast. Any stronger cells could be capable of locally heavy rain. Temperatures Thursday top out in the 70s and 80s. Rain and storm chances then ramp up Thursday night through Friday with the tandem of an upper level disturbance arriving from the west and a secondary reinforcing cold front arriving from the north. This is where our heaviest rainfall signal exists and the latest probabilities from ensemble guidance indicate a medium (30- 60%) chance for at least of 1 inch of rain from Thursday night through Friday night. While cooler temperatures keep instability lower, we will keep a mention for the possibility of some isolated stronger cells as well, capable of at least small hail and gusty winds. The rain and storm chances should push out of the area to the south-southeast entering Saturday morning. This front also helps to advance even cooler air into the region. It allows for the morning lows to dip into the 40s and 50s both Saturday and Sunday morning while the afternoon highs Saturday only range in the mid 60s to the mid 70s.

Rain chances lower and temperatures gradually climb Sunday through early next week with the returning of a south-southeasterly low- level flow and a modest upper level ridging pattern sliding east from the Desert Southwest. Afternoon highs return to the 80s while overnight lows climb back into the 60s.

AVIATION

(12Z TAFS) Issued at 547 AM CDT Tue Apr 28 2026

Only changes made to the forecast were to remove mention of IFR CIGs at SAT and to introduce Haze through the remainder of the day today at AUS, SAT, and SSF. Winds will remain on the breezy side out of the east-southeast. VFR ceilings expected 18Z-07Z tonight followed by yet another round of MVFR.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 92 72 85 66 / 10 10 30 30 Austin Bergstrom Intl Airport 92 71 86 66 / 10 10 30 30 New Braunfels Muni Airport 92 72 87 66 / 10 10 30 20 Burnet Muni Airport 91 68 80 63 / 10 10 30 30 Del Rio Intl Airport 95 76 94 71 / 0 0 30 40 Georgetown Muni Airport 92 69 82 64 / 10 10 30 30 Hondo Muni Airport 94 71 89 68 / 10 0 30 20 San Marcos Muni Airport 93 71 87 66 / 10 10 30 20 La Grange - Fayette Regional 92 73 89 68 / 10 10 30 20 San Antonio Intl Airport 93 73 88 68 / 10 10 30 20 Stinson Muni Airport 94 74 90 69 / 10 10 20 20

EWX WATCHES/WARNINGS/ADVISORIES

None.