textproduct: Austin/San Antonio

KEY MESSAGES

- Very warm with isolated storms possible late this afternoon and this evening

- A wet and active pattern awaits starting early next week. Heavy rain could lead to localized flooding.

SHORT TERM

(Today through Monday) Issued at 129 AM CDT Sun May 17 2026

Expect another warm day for today with many topping out in the low 90s under mostly cloudy skies to perhaps mid 90s for those across the Rio Grande Plains where more sun breaks out. Additionally, it will be quite muggy as moisture increases due to strong southerly flow at the surface. This flow will also help to push our PWATs above climatological normals with values in the 1.6 to 1.8 inch range. Most areas should continue to remain dry until later in the afternoon/evening. Forecast soundings continue showing a moderate to strong cap, so any potential ripples within the southwest flow aloft thanks to the upper level short wave moving across the Southern Plains could be just enough to weaken it which would open the door for an isolated storm or two. With this increased moisture and relatively high Precipitable water values any convection that does manage to form could definitely drop a quick quarter to perhaps an inch of rain in any of the heavier cells. Hi-res models have latched onto this recently with a handful suggesting convection forming over the western Hill Country and spreading eastward across the I-35 Corridor. The flip side of this due to the cap, is we could have absolutely nothing happen and it just be a rather warm and muggy day. Decided to continue to keep low chance pops (20% or less) across these areas in case this scenario were to occur.

By Monday most activity if it develops should be well east of our area lending to another warm and muggy day under mostly cloudy to partly cloudy skies as moisture remains across the area. We could see heat indices approach the low 100s for many areas with heat indices above 105 possible across the Winter Garden and Rio Grande Plains. We should have a stronger cap in place for Monday but it's possible we could see a storm try to break it, if it does we could see heavy rainfall along with the potential for small hail and gusty winds.

LONG TERM

(Monday night through Saturday) Issued at 129 AM CDT Sun May 17 2026

A big pattern change is forecasted for the long term as we remain under southwest flow aloft which usually allows for disturbances to impact our area and take advantage of the rich moisture and unstable air in place. As such, it seems likely that multiple disturbances could impact our area as a dryline will be situated just off to our west across west TX and will try to advance eastward each day. This should set off convection across northern Mexico that would work its way across the Rio Grande Plains and Southern Edwards Plateau. Depending on how robust this activity becomes will determine how far eastward it advances. Additionally, a cold front located across the Southern Plains will try to make its way southward across northern Texas. By Wednesday most models have this front located somewhere just to our north. As this front slides southward convection is expected to blossom along it with many areas seeing a localized heavy rainfall threat as this front slowly stalls somewhere across the area. This now stationary front will be the continued focus for additional shower and thunderstorm activity throughout the period as we remain entrenched in a very moist airmass with continued southwest flow aloft.

Even after this front moves through our area and or washes out, both Global models continue to hint at this pattern continuing into and even beyond next weekend as disturbances aloft continue to ride over our area and ignite the potential for additional rounds of showers and thunderstorms. While most of the rain will be beneficial for many areas there are some beginning signs that we could see heavier rounds that may lead to localized flooding concerns. However the specific areas, amounts and placements are too early to discuss until more details get ironed out. Bottom line is an active and wet pattern looks likely for the entire area starting early next week. Continue to check back as details continue to get clearer over the coming days.

AVIATION

(06Z TAFS) Issued at 1218 AM CDT Sun May 17 2026

MVFR ceilings are rapidly spreading over the I-35 Corridor. Ceilings will spread to DRT within the next few hours. All terminals will be MVFR through the night with VFR conditions returning by around noon. Winds will be from the southeast and will be strong and gusty again. MVFR ceilings will return again late tonight.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 91 78 93 78 / 10 20 20 10 Austin Bergstrom Intl Airport 91 79 93 79 / 10 20 10 10 New Braunfels Muni Airport 91 77 93 77 / 10 10 10 10 Burnet Muni Airport 86 75 88 75 / 10 20 30 0 Del Rio Intl Airport 96 78 99 78 / 0 10 0 0 Georgetown Muni Airport 90 77 91 77 / 10 20 20 10 Hondo Muni Airport 91 78 92 77 / 10 10 10 20 San Marcos Muni Airport 92 78 93 78 / 10 10 10 10 La Grange - Fayette Regional 91 79 91 78 / 10 10 10 20 San Antonio Intl Airport 91 78 93 78 / 10 10 10 10 Stinson Muni Airport 92 78 94 78 / 10 10 10 10

EWX WATCHES/WARNINGS/ADVISORIES

None.