textproduct: Austin/San Antonio

KEY MESSAGES

- Low chance for a few showers and storms today.

- Active weather pattern from mid-week through the upcoming Memorial Holiday weekend. Heavy rain at times could lead to localized flooding.

SHORT TERM

(Today through Tuesday) Issued at 124 AM CDT Mon May 18 2026

Today will be another warm and muggy day under mostly cloudy to perhaps partly cloudy skies as moisture remains strewn across the area. Highs should generally top out in the low 90s north and upper 90s south. We should see more peaks of sun than we did on Sunday which in turn will give us heat indices or "feels like" temps close to 100 for many areas with heat indices above 105 possible across the Winter Garden and Rio Grande Plains. We also should have a stronger cap in place today but it's possible we could see a storm try to break it mainly in the late afternoon/evening, if it does we could see a burst of heavy rainfall along with the potential for small hail and gusty winds. If any activity does form it should wane significantly after sunset with the loss of daytime heating. Tuesday should be another warm and very muggy day as we remain entrenched underneath this southwest flow aloft and southerly flow at the surface. A cold front located to our north will be on its way southward while a dryline located over northern Mexico and West TX will also be advancing eastward throughout the day. Both of these features should be the next focus for our next round of convection and heavy rainfall potential. This would likely commence late Tuesday afternoon and continue through the evening, more on that below.

LONG TERM

(Tuesday night through Sunday) Issued at 124 AM CDT Mon May 18 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 have advanced eastward through the day Tuesday before beginning its daily retreat back westward. Similarly, the previous mentioned cold front will be advancing southward and as it does so numerous Hi-res models and ensembles suggest that convection would blossom along and ahead of this front by Tuesday evening. Most models highlight areas to our north across central TX where discrete supercells would initially be possible before quickly congealing into a line and working its way southeastward towards our area. What's interesting to note is just how consistent all of these models continue to be at targeting this scenario. As this convection moves closer we could see a secondary line of storms form out west from the aforementioned dryline convection if it forms over northern Mexico. Depending on how robust this activity becomes will determine how far eastward it advances. SPC currently has most of the area in a level 1 or 2 of 5 risk for severe weather for this time period.

With the continued moisture remaining across the area any convection that does form will be capable of very heavy rainfall. Eventually this front becomes stationary towards the middle of the week and washes out somewhere across our 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.

The main forecast challenge in the coming days will be identifying which features will provide the strongest focus for storms each day. The pattern transitions from a dryline/shortwave-driven severe weather pattern late Tuesday to a frontal and eventually a surface boundary-driven heavy rain and storm regime later in the week. 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 due to the difficult timing and placement of these additional rounds and the numerous surface and outflow boundaries from previous convection it's still too hard to decipher which areas may see heavier amounts and when. 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

(12Z TAFS) Issued at 547 AM CDT Mon May 18 2026

All terminals have MVFR ceilings this morning and will remain MVFR until around noon. Ceilings will lift to VFR. Wind speeds will increase and become gusty this afternoon. MVFR ceilings will return around midnight tonight. There is a less than 20% chance for showers or thunderstorms during the evening in Austin and San Antonio. If convection does form, it could lower ceilings or visibility to MVFR for a short time.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 92 78 91 72 / 10 20 50 70 Austin Bergstrom Intl Airport 92 79 91 73 / 10 20 50 70 New Braunfels Muni Airport 92 78 91 72 / 10 20 40 60 Burnet Muni Airport 88 75 87 70 / 10 10 50 70 Del Rio Intl Airport 98 78 95 72 / 10 10 30 50 Georgetown Muni Airport 91 77 90 71 / 10 20 60 70 Hondo Muni Airport 92 78 91 72 / 10 20 40 60 San Marcos Muni Airport 92 78 92 73 / 10 20 40 70 La Grange - Fayette Regional 91 79 91 73 / 10 20 40 60 San Antonio Intl Airport 92 78 91 73 / 10 20 40 60 Stinson Muni Airport 93 79 92 73 / 10 20 30 60

EWX WATCHES/WARNINGS/ADVISORIES

None.