textproduct: Austin/San Antonio

KEY MESSAGES

Updated at 138 PM CDT Mon Jul 20 2026

- River Flood Warnings continue for Major to Moderate flooding along the Nueces and Frio River basins. Elevated flows on area rivers continue, but gradually improving conditions are in store over the next several days.

- The heat builds over the region through mid-week, with peak heat index values near 108 degrees possible Wednesday and Thursday generally along and east of the Interstate 35 corridor.

- Tropical Depression Two continues over the northeast Gulf and we will monitor for possible forecast impacts on south central Texas.

SHORT TERM

(Tonight through Tuesday night) Issued at 138 PM CDT Mon Jul 20 2026

A mid and upper level low is noted across far west Texas early this afternoon. We did note some weak radar returns earlier this morning and will continue to monitor radar and satellite trends across this region. So far, the hi-res models keep convection mostly limited to the Big Bend region and for now we will continue a dry forecast for Val Verde County.

Otherwise, dry conditions along with warming temperatures are in store across the region through Tuesday night. Southeasterly flow in the lower levels will continue the feed of moisture from the Gulf. However, we are noting some drier air in the 5-10k AGL layer on forecast soundings and with mixing, we should see some drop in the dew points in the afternoon today and Tuesday. This is expected to keep afternoon heat index values below 108 degrees for most of the region. Afternoon highs will still peak from near 90 to near 100 degrees both today and Tuesday.

LONG TERM

(Wednesday through next Monday) Issued at 138 PM CDT Mon Jul 20 2026

As Wednesday approaches, we expect to see an increase in lower and mid level moisture along with a slight weakening of afternoon wind speeds. This along with a upward bump in temperatures may push areas generally along and east of I-35 into Heat Advisory criteria. While heat index values of 108 degrees are expected to be the greater concern, we could also see a few locations reach 103 degrees on Wednesday.

The forecast for Thursday into Saturday will depend on what transpires in the Gulf. It is too early to tell what impacts may occur across south central Texas, so stay tuned to the forecast this week. For now, we will not show much in the way of rain chances, but this may certainly change with subsequent forecasts. Temperatures look to remain near or above normal and we may need to monitor Thursday for additional heat headlines.

For the remainder of the forecast period, mid and upper level high pressure remain the dominant weather feature over south central Texas. This should result in dry weather along with seasonal temperatures.

AVIATION

(18Z TAFS) Issued at 1239 PM CDT Mon Jul 20 2026

VFR will prevail through the forecast period at all TAF sites through most of the forecast period. Probabilistic guidance indicates there is a low chance (30% or less) of MVFR ceilings after 08-09Z at KAUS, KSAT, and KSSF, before clearing out by 14-15Z. Opted to include a SCT020 mention with this issuance, but additional refinements may be needed in subsequent TAFs if probabilities and confidence increases. Otherwise, expect southerly to southeasterly winds below 10 knots through the afternoon hours before falling below 5 knots tonight.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 97 73 100 79 / 0 0 0 0 Austin Bergstrom Intl Airport 96 72 99 78 / 0 0 0 0 New Braunfels Muni Airport 96 71 98 76 / 0 0 0 0 Burnet Muni Airport 97 72 99 77 / 0 0 0 0 Del Rio Intl Airport 95 75 98 74 / 0 0 0 0 Georgetown Muni Airport 97 73 100 80 / 0 0 0 0 Hondo Muni Airport 95 72 97 73 / 0 0 0 0 San Marcos Muni Airport 96 70 98 75 / 0 0 0 0 La Grange - Fayette Regional 98 73 101 77 / 0 0 0 0 San Antonio Intl Airport 95 73 97 76 / 0 0 0 0 Stinson Muni Airport 97 73 97 76 / 0 0 0 0

EWX WATCHES/WARNINGS/ADVISORIES

None.