textproduct: Austin/San Antonio

KEY MESSAGES

- Rain free with slightly above average temperatures mid to late week - Increasing humidity with elevated heat indices and returning rain/storm chances entering early next week

SHORT TERM

(Tonight through Wednesday night) Issued at 129 PM CDT Tue May 12 2026

Mid-level ridging will be in control over the state for the short term while surface high pressure moves eastward late today into tonight. The highs this afternoon should be near average under mostly sunny skies. Light easterly winds will start to become southeasterly this evening into Wednesday. With the afternoon dew points in the 50s to low 60s, this should keep the humidity with peak daytime heating in the tolerable range. Wednesday will be slightly warmer compared to today with many seeing highs closer to the 90 degree mark. The overnight lows are expected to remain seasonable in the low to mid 60s through the short term. There is potential for some nocturnal cloud cover and patchy morning fog across the coastal plains where the dew points are the highest during each night. Elsewhere, skies likely stay mostly clear.

LONG TERM

(Thursday through next Tuesday) Issued at 129 PM CDT Tue May 12 2026

Late this week would see the mid-level ridging start to gradually flatten and for the low-level southeasterly flow to increase to a more moderate but persistent speed with surface winds at 10 to 20 mph and higher gusts. This flow helps advect and maintain greater low-level moisture (dew points) across the region with time. On Thursday afternoon, the humidity may be lowest of the week but expect for this to change Friday into the weekend and beyond into early next week. Thursday into early Sunday looks to remain rain free with capping and generally a lack of enough lift from any passing subtle shortwaves or with the dryline in West Texas. This changes late Sunday through early next week, with a more defined trough developing across the Southwestern CONUS and a stronger southwest flow aloft over Texas compared to the lighter west- southwest counterpart from late this weekend into Saturday. This coupled with a rich low-level moisture profile with the dew points that climb into 70s, to even near 80 degrees across the coastal plains will support medium (30-60%) chances for rain and storm activity starting after sunset Sunday. As common for this time of year, we'll have to analyze the capping inversion and any other mesoscale features as we approach this time frame.

Temperatures late this week into early next week trends slightly above average with highs ranging from the mid 80s over the Hill Country to the mid 90s across the Rio Grande Plains. The I-35 corridor will mainly trend within the upper 80s to low 90s. With arrival of that very humid and more oppressive air this weekend through early next week, the peak heat indices become elevated across the region outside of the Hill Country, with indices that peak from the upper 90s to in excess of 100 degrees. Overnight temperatures become very warm as well with the morning lows only dipping into the mid to upper 70s for most. May even see a few locations across the coastal plains struggle to fall below 80 degrees at times. Cloud coverage will be greatest overnight into each morning before skies become mostly to partly cloudy each afternoon.

AVIATION

(18Z TAFS) Issued at 1212 PM CDT Tue May 12 2026

Very little change to the going forecast as VFR ceilings and winds generally less than 10 kts out of the east and east-southeast are expected today. Winds will drop off to less than 3 kts at AUS, SAT, and SSF by 03Z tonight and remain light and variable. Expect a return to southeasterly winds around 8-12 kts by mid-morning Wednesday at DRT, with other sites remaining light and variable.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 65 91 67 91 / 0 0 0 0 Austin Bergstrom Intl Airport 62 90 65 92 / 0 0 0 0 New Braunfels Muni Airport 62 90 64 91 / 0 0 0 0 Burnet Muni Airport 63 89 65 88 / 0 0 0 0 Del Rio Intl Airport 67 94 69 94 / 0 0 0 0 Georgetown Muni Airport 63 89 66 90 / 0 0 0 0 Hondo Muni Airport 62 90 63 93 / 0 0 0 0 San Marcos Muni Airport 62 90 64 91 / 0 0 0 0 La Grange - Fayette Regional 63 89 66 91 / 0 0 0 0 San Antonio Intl Airport 65 91 66 91 / 0 0 0 0 Stinson Muni Airport 65 92 65 93 / 0 0 0 0

EWX WATCHES/WARNINGS/ADVISORIES

None.