textproduct: Austin/San Antonio

KEY MESSAGES

- Rain free through Sunday afternoon with low to medium chances for thunderstorms and locally heavy rainfall Sunday night through Wednesday.

- Increasing humidity and heat indices through Tuesday, with some spots feeling like 100-105+ Sunday, Monday, and Tuesday.

SHORT TERM

(Today through Friday) Issued at 1213 AM CDT Thu May 14 2026

Mid to upper level ridge axis in the early evening was juxtaposed directly over Central TX with the most concentrated anticyclonic wind circulation noted at the 700 mb level. This correlates with the poor air dispersion and Ozone Action day alerts for today conveyed through us by the TCEQ. The mid level portion of the ridge axis coils up over the middle/upper TX coast by 00Z Friday while at higher levels the ridge dampens into a broad but still potent upper ridge to continue a stable airmass below. The subtle change should lend toward increasing winds through the latter part of the day as the overall ridge aloft drifts slowly east with slightly falling heights building east into W TX. The winds should still be light to moderate over east counties, but around DRT/ECU LAV guidance is suggesting gusts over 25 mph possible where the gradient tightens fastest. Meanwhile the latest NAM time sections depict a more shallow moist layer than it did yesterday evening, and this has led to a better mix-out of surface dew points with the large mid-level dry layer, and we saw that in the afternoon RH percentage values mixing down into the low to mid 20s. Portions of Val Verde county should see this again today and the extra winds and near normal amounts of recent precipitation for May might lead to locally elevated fire weather conditions. Again with good mixing and ridging overhead our high temperatures today should get about a 1 to 3 degree bump over yesterday's MaxT values.

The large dry layer in the mid levels is shown in the NAM data to shrink considerably in the Thursday night to Friday time-frame, and we think this should result in a big jump in afternoon dew points from the mostly 50s values we'll see for 00Z Friday to mostly 60-65 degree values for 00Z Saturday. This could slow down the daily warming trend of ambient heat, but apparent temperatures, which actually might have fallen below ambient temperature values in some places, will begin to climb a degree or 3 warmer than the ambient temperature values for Friday afternoon. As Friday should be another opportunity for another great fair weather day for outdoor opportunities, the heat index values at this point should remain mostly tolerable, especially with those afternoon breezes and gusts trending upward. The morning lows for Friday will see the most noticeable jump with mainly a 65 to 70 degree range expected.

LONG TERM

(Friday night through Wednesday) Issued at 1213 AM CDT Thu May 14 2026

The slow erosion of the upper ridging aloft and upstream troughing will continue to deepen the moist layer and remove the dry mid level layer over the weekend. A capping inversion is expected to hold and no PoPs are the continued guidance for through Sunday afternoon. Beneath that cap will be a pile up of higher moisture humidity and heat index impacts that continue to rise each day going into Tuesday. Saturday's values are somewhat typical for a stable May afternoon, but Sunday begin to push into that need for messaging territory, where most values begin hitting in the 95 to 105 window. Then Monday and Tuesday, the values peak with both days depicting mostly upper 90s to around 108 type values.

Now those higher heat indices may come with a caveat. The capping inversion is expected to hold through the afternoon Sunday and for most areas Monday, but destabilizing conditions begin to warrant some low chance PoPs for western counties Sunday night and expanded into the rest of the forecast area by late Monday. Some storms could become strong with heavy downpours, but it's still too early to speculate on the assessments from the SPC and WPC with the developing unstable SW flow aloft being somewhat broad and vague. This will be the case going into Wednesday with Tuesday through Wednesday being the period that could potentially support the best rainfall coverage.

AVIATION

(06Z TAFS) Issued at 1213 AM CDT Thu May 14 2026

VFR conditions are expected through the period at all terminals with high clouds moving over the area. Southerly wind under 8 knots is expected through sunrise, then south to southeast wind increases during the morning hours across South Central Texas. For I-35 sites, wind will generally be 10-15 knots with occasional gusts to 20 knots. Stronger wind is expected out west today from 12-16 knots with gusts around 25 knots. Subtle weakening in wind speeds will be seen after sunset but remain from the south around 10 knots through the overnight hours. Early Friday morning, MVFR ceilings are expected to develop over the coastal plains and may make it into the I-35 corridor closer to 12Z.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 92 69 92 71 / 0 0 0 0 Austin Bergstrom Intl Airport 91 69 92 71 / 0 0 0 0 New Braunfels Muni Airport 91 67 92 69 / 0 0 0 0 Burnet Muni Airport 88 67 88 69 / 0 0 0 10 Del Rio Intl Airport 95 72 95 72 / 0 0 0 0 Georgetown Muni Airport 90 69 91 71 / 0 0 0 0 Hondo Muni Airport 90 66 92 70 / 0 0 0 0 San Marcos Muni Airport 92 68 93 71 / 0 0 0 0 La Grange - Fayette Regional 92 68 92 71 / 0 0 0 0 San Antonio Intl Airport 91 68 92 71 / 0 0 0 0 Stinson Muni Airport 91 69 93 71 / 0 0 0 0

EWX WATCHES/WARNINGS/ADVISORIES

None.