textproduct: Austin/San Antonio

KEY MESSAGES

- Line of strong to severe storms with locally heavy rain possible Tuesday evening/night.

- Active weather pattern from mid-week through the upcoming Memorial Holiday weekend. Rounds of storms with heavy rain could lead to localized flooding.

SHORT TERM

(Today through Wednesday) Issued at 217 AM CDT Tue May 19 2026

Breezy and warm conditions continue tonight under overcast skies. Lows early Tuesday morning will be in the 70s across South Central Texas with most climate sites once again nearing their record high minimum temperatures. Breezy, humid and hot conditions continue during the day tomorrow although gusts should be a bit weaker than those seen Monday in the 20-25 mph range through the afternoon. Heat index values may approach triple digits from the I-35 corridor and areas east but rise from 100-107 degrees along the Rio Grande.

Dry conditions are likely through late this afternoon before a weak cold front slowly moves towards our area evident by likely ongoing convection north of our area in the afternoon. Further west, isolated to scattered storms may develop near the dry line over the higher terrain of Mexico then make its way wast towards the Rio Grande before colliding with the front. Scattered to widespread showers and thunderstorms will be nearing the Hill Country from the north or northwest in the evening then move across the area tonight into Wednesday morning.

A Level 2 of 5 risk continues for severe weather with the greatest risk generally along and west of the I-35 corridor. While there could be some isolated storms ahead of the front and in the west ahead of the dryline, the main activity will likely be in a line or broken line as it enters our area this evening. The main severe risk continues to be isolated strong to severe wind gusts, though potentially large hail cannot be ruled out with the strongest updrafts. There do remain some differences on how quickly this activity moves across the area which will have an effect on localized rainfall amounts. WPC highlights a level 2 of 4 risk for isolated excessive rainfall which could lead to localized flash flooding for a majority of our area including the Hill Country, I-35 corridor and Coastal Plains. General rainfall amounts of around 0.75" to 1" are expected but pockets of locally higher amounts may be in the 3-5" range.

Most storm activity will be south of our area near sunrise with more stable conditions in place as the atmosphere recovers. Cooler temperatures in the 80s are expected for a majority of the area Wednesday. While some isolated showers or a thunderstorm cannot be ruled out during the day, it seems more likely rain-free conditions will continue into the afternoon Wednesday.

LONG TERM

(Wednesday night through Monday) Issued at 217 AM CDT Tue May 19 2026

An active pattern continues in the extended period with daily rain chances due to persistent upper-level southwesterly flow bringing multiple disturbances moving over the area.

The atmosphere may still be recovering for most areas Wednesday evening but a highly moist airmass and stalled surface boundary to the north will allow for continued medium to high rain chances Wednesday night and Thursday. Some guidance indicates a complex of storms developing in West Texas and moving towards the area late Wednesday night and gradually working its way across the area Thursday. There is some potential for severe weather but higher confidence would be for some heavy rain given high precipitable water values. A Slight (Level 2 of 4) Risk for excessive rainfall remains valid on Thursday which includes portions of the Hill Country, I-35 corridor and Coastal Plains. As mentioned previously, each round of storms will influence the next days storm potential so confidence on precise timing and placement for any activity is low in the long term forecast. That said, the weekend remains another time period to watch as models indicate a passing shortwave trough during this period with no real definitive ending to this pattern into early next week.

Each round of rainfall will lead to a deeper moistening of soils and possibly more runoff late week as grounds saturate. The pattern may lead to widespread beneficial rain for most areas but areas that receive repeated rounds and higher totals will likely see increasing potential for flash flooding or river flooding. Given the storm potential can rely on leftover boundaries from previous days, its hard to say exactly where the highest rain totals will be. Towards the end of the week it is likely most of, if not all, of South Central Texas will see some rainfall this week. Continue to check the forecast as the week progresses for those with plans this weekend for the Memorial Day holiday.

AVIATION

(06Z TAFS) Issued at 1246 AM CDT Tue May 19 2026

Ceilings will be MVFR overnight at all terminals. VFR conditions will return by late morning or early afternoon. Showers and thunderstorms will be possible starting around noon and becoming more likely during the late afternoon. We've targeted between 03Z and 06Z as the most likely time for thunderstorm, but they could come earlier or later.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 91 72 85 71 / 40 80 30 80 Austin Bergstrom Intl Airport 91 73 85 72 / 30 80 40 80 New Braunfels Muni Airport 91 72 86 71 / 30 80 40 80 Burnet Muni Airport 88 69 82 69 / 40 80 30 80 Del Rio Intl Airport 95 72 89 69 / 30 50 40 100 Georgetown Muni Airport 89 71 83 70 / 40 80 30 70 Hondo Muni Airport 91 72 86 70 / 20 80 40 90 San Marcos Muni Airport 92 73 86 72 / 30 80 40 80 La Grange - Fayette Regional 91 73 86 73 / 30 70 40 70 San Antonio Intl Airport 92 73 86 72 / 20 80 40 80 Stinson Muni Airport 93 74 87 72 / 20 80 40 80

EWX WATCHES/WARNINGS/ADVISORIES

None.