textproduct: Austin/San Antonio

KEY MESSAGES

- Low chances for rain this afternoon or evening. Isolated showers and storms may develop with the most favored areas over the southern Edwards Plateau and Hill Country.

- Active and unsettled weather pattern continues into next week. Multiple rounds of storms with heavy rain could lead to localized flooding.

SHORT TERM

(Today through Friday) Issued at 1258 AM CDT Thu May 21 2026

A complex of storms just north of our area and a strong complex further south are noted on radar early this morning. The overnight forecast has evolved with lesser chances for widespread rain across the area given only showers and non-severe, moderate thunderstorms between the gap in these systems. Our area may mostly be rain-free by sunrise leaving a challenging daytime forecast in place as more energy may be around to redevelop thunderstorms this afternoon. Guidance seems to favor the southern Edwards Plateau, Hill Country, and possibly into the I-35 corridor for this potential today. Any outflows could also provide the trigger for development leading to a low confidence forecast for today. Activity will likely be isolated in nature so many will still see dry conditions. For storms that do form, continued high moisture in place will allow for a heavy rainfall potential which could lead to localized flooding. Additionally, a Level 1 of 5 potential for severe weather is seen in the far west along the Rio Grande where the highest instability develops today with any storms capable of producing large hail and damaging wind gusts.

Another disturbance moves over the area today and could initiate storms out west which would move east later tonight. However, guidance has backed off on this potential with storms wakening before they make much progress eastward leaving drier conditions for tonight into Friday. Models do continue to be consistent with drier conditions for Friday as remain between a departing disturbance in the east and another disturbance west of Texas so have trended NBM PoPs down during this time.

LONG TERM

(Friday night through Wednesday) Issued at 1258 AM CDT Thu May 21 2026

Our unsettled weather pattern remains in place through next week, likely even beyond the official seven day forecast. South Central Texas will mainly be under southwesterly flow aloft allowing for disturbances to traverse over the area. Additionally,continued average to above average moisture keeps the fuel for periods of showers and thunderstorms during this time.

As each round of storms moves across portions of our area, more stable conditions behind these features will allow for periods of dry weather as well as the atmosphere recharges. So while prolonged chances for precipitation are seen in the extended forecast, periods of dry weather are also expected. As each round helps determine the set up for the next, it's hard to say with confidence exactly when dry and wet periods will be, hence, the continued rain chances. In this pattern, the short term forecast is the main one to watch as details can be better realized.

That said, there is good agreement in models that a trough will be located over the Baja Peninsula Friday night, lifting northeast across Texas through early Sunday. A disturbance ahead of this main feature could kick off some thunderstorms in the west late Friday or early Saturday though ensemble guidance more favors locations from the Hill Country to the Coastal Plains Saturday evening into Sunday. Again, details will be refined with each passing forecast but the Saturday into Sunday timeframe does look to be one to watch for potential stormy conditions.

The forecast becomes even more complicated as an upper trough/closed low remains relatively stationary over Texas through Tuesday as where this feature sets up will play a role in rain chances during this time. Another trough then digs over the western US towards the middle of next week moving our stalled system along but reestablishing southwesterly flow over the area again.

Every rain event will bring soils closer to saturation increasing the potential for run off which can lead to flash flooding or river flooding. Flood Watches may need to be considered as we progress further into the week and weekend. Continue to monitor the forecast and always have a way to receive warning information.

AVIATION

(12Z TAFS) Issued at 639 AM CDT Thu May 21 2026

IFR cigs are forecast for the next few hours for the San Antonio area terminals. Then MVFR conditions for the rest of the morning period before cigs lift to VFR category. For KAUS, MVFR cigs are anticipated to prevail for the morning hours before VFR cigs dominate the area. For KDRT, MVFR cigs are projected to remain through late this morning and then lifting to VFR this afternoon. There is a chance for showers and storms along the Rio Grande Plains late this afternoon and evening. With that said, included a PROB30 group for KDRT late afternoon into the evening for the possibility of thunderstorms. A light east to southeast flow is forecast through the forecast period.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 81 69 88 72 / 50 30 10 40 Austin Bergstrom Intl Airport 81 69 88 72 / 50 30 10 40 New Braunfels Muni Airport 83 68 88 71 / 50 30 20 40 Burnet Muni Airport 78 66 86 69 / 50 30 10 40 Del Rio Intl Airport 85 68 90 71 / 20 20 10 30 Georgetown Muni Airport 80 67 87 70 / 40 30 10 40 Hondo Muni Airport 83 67 85 70 / 30 20 10 50 San Marcos Muni Airport 81 68 88 71 / 50 30 20 30 La Grange - Fayette Regional 82 69 86 72 / 50 30 30 30 San Antonio Intl Airport 83 70 87 72 / 40 20 10 40 Stinson Muni Airport 84 70 87 72 / 40 30 10 50

EWX WATCHES/WARNINGS/ADVISORIES

None.