textproduct: Austin/San Antonio

KEY MESSAGES

- Low chance for a few showers and storms through early Sunday evening.

- A slow warming trend develops tomorrow and continues through the upcoming week.

SHORT TERM

(Tonight through Monday night) Issued at 128 PM CDT Sun Jun 21 2026

We will carry a low chance (20-30%) for showers and storms this afternoon and early evening for the coastal plains region into portions of the I-35 corridor. Some breaks in the cloud cover along with outflow boundaries moving northward from the area of persistent convection along the middle Texas may be enough to help gin up some showers and storms. With the loss of daytime heating, any activity that develops will weaken by mid-evening. Low clouds will return to all areas late tonight into tomorrow morning and with southerly winds in place, overnight lows in the 70s can be expected. We will keep the forecast dry on Monday as the subtropical ridge strengthens across Texas. Highs will be in the 90s and with humid conditions in place, a few spots east of I-35/I-37 may briefly approach heat index values of 108 degrees. For now, we will not issue a Heat Advisory as it appears these conditions will remain isolated and brief in nature.

LONG TERM

(Tuesday through next Sunday) Issued at 128 PM CDT Sun Jun 21 2026

The forecast as we head into the middle of the week remains stable as high pressure aloft remains the dominant weather feature of interest. We will continue to see periods of late night and morning low clouds followed by a clearing trend in the afternoon and early evening hours. Highs will largely remain in the 90s, with near 100 possible along the Rio Grande. Overnight lows will be in the 70s as southerly winds remain intact. The forecast will also remain dry, but we may have to monitor for some isolated afternoon convection near the coastal plains as the sea breeze moves inland.

Late this week into early next week, the models show the ridge begins to flatten and weaken as an upper low over the Pacific northwest deepens. Despite the weakening of the upper level ridge, the low-level thermal ridge will change little. This will result in continued persistence in the temperature forecast along with a dry forecast remaining intact.

AVIATION

(18Z TAFS) Issued at 1236 PM CDT Sun Jun 21 2026

Some brief MVFR clouds will linger over the next 1-2 hours at area TAF sites, with VFR then expected for the afternoon and early evening. Some isolated convection may develop from the coastal plains northward to near I-35 late this afternoon. We will not mention any SHRA or TSRA for now as chances are too low. Low clouds return by late evening and have opted to start the onset of MVFR a little earlier based on overnight trends and forecast soundings. We have also kept the mention of IFR at SAT and SSF based on persistence and the latest guidance. Clouds will likely persist through tomorrow morning, with VFR returning early afternoon.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 79 95 78 95 / 0 0 0 0 Austin Bergstrom Intl Airport 79 95 78 95 / 0 0 0 0 New Braunfels Muni Airport 77 93 77 94 / 10 0 0 0 Burnet Muni Airport 77 93 76 94 / 0 0 0 0 Del Rio Intl Airport 78 98 78 98 / 0 0 0 0 Georgetown Muni Airport 78 94 77 95 / 0 0 0 0 Hondo Muni Airport 77 92 75 93 / 0 0 0 0 San Marcos Muni Airport 78 95 77 95 / 10 0 0 0 La Grange - Fayette Regional 79 94 78 94 / 0 0 0 0 San Antonio Intl Airport 78 93 78 93 / 10 0 0 0 Stinson Muni Airport 78 93 77 93 / 10 0 0 0

EWX WATCHES/WARNINGS/ADVISORIES

None.