textproduct: Austin/San Antonio

KEY MESSAGES

- Isolated late afternoon to evening storms over the southern Edwards Plateau and near the Rio Grande today and Tuesday.

- Warm and humid conditions continue throughout the week.

SHORT TERM

(Today through Tuesday) Issued at 1235 AM CDT Mon Apr 13 2026

An upper-level shortwave is in the process of moving northeast out of our area, carving out marginally more stable and drier air behind it. Precipitable water values are expected to drop from about 1.8 inches to a still moist but more palatable 1.2-1.4 inches. This should lead to a decrease in shower activity Monday compared to the past few days, but low-level southerly flow and southwesterly flow aloft will still support a generally unsettled weather pattern. Isolated light showers are possible during the late morning hours over the Coastal Plains before mixing out in the afternoon. Later in the day, sufficient heating supports an isolated thunderstorm potential along the dry line over West Texas and Mexico, along with a marginal risk for mainly large hail. Some of these may drift towards the Rio Grande and southern Edwards Plateau near sunset. However, more stable conditions Monday night should keep these storms relatively short-lived with most not making it very far into our area.

Conditions Tuesday support a similar evolution to Monday, with initiation along the dry line possible later in Tuesday afternoon over West Texas and the southern Edwards Plateau. The slight difference is that troughing over the western US will be closer to the area, driving more forcing for ascent and favoring an uptick in storm coverage and persistence relative to Monday. Highs both Monday and Tuesday are forecast to be in the 80s to low 90s, with humid air prevailing.

LONG TERM

(Tuesday night through Sunday) Issued at 1235 AM CDT Mon Apr 13 2026

A prominent portion of vorticity on the leading edge of longwave troughing over the western US is forecast to move across the Central and Southern Plains Wednesday into Thursday. The approach of this disturbance is forecast to increase moisture advection into our area with an accompanying increase in rain and storm chances. The favored area for storm development is focused north of our region, but medium range models show extension of potentially a broken line of storms extending to areas north of the I-10 corridor sometime late Wednesday into early Thursday. Isolated threats for severe weather and excessive rainfall are possible with this activity.

While the overall pattern of southwesterly flow continues after this midweek action, brief upper-level ridging in its wake looks to provide a brief window of respite from the active weather on Thursday, with slightly drier air aloft. Towards the end of the week, as the broad western US trough slides farther east, ensembles are in agreement that a decently strong mid-April cold front will approach South-Central Texas Saturday into Sunday. Rain and thunderstorms are probable on this front, but it is too early to gauge the severe weather and heavy rain risk. A period of below- average temperatures is possible behind the front with air spilling south from the Rockies, switching up the airmass over South-Central Texas to a drier and cooler one.

AVIATION

(12Z TAFS) Issued at 504 AM CDT Mon Apr 13 2026

Low end MVFR conditions are holding for KAUS, KSAT, and KSSF as of this writing. However, still thinking that cigs could lower a bit to IFR category for a few hours after day break. Therefore, keeping the current TAF forecast into the 12Z aviation package. Cigs to lift into VFR conditions by 20Z. Southeast to south wind flow is forecast to prevail through the forecast period. Late this afternoon into the evening, storms are forecast to develop ahead of the dryline over west Texas and push into Del Rio area. A PROB30 has been introduced to account for this potential from 03Z to 06Z Tuesday.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 84 69 84 68 / 20 10 10 10 Austin Bergstrom Intl Airport 84 67 84 68 / 20 10 10 10 New Braunfels Muni Airport 84 68 84 68 / 20 10 10 10 Burnet Muni Airport 83 67 81 67 / 10 10 20 20 Del Rio Intl Airport 88 70 84 69 / 10 30 40 40 Georgetown Muni Airport 83 67 82 67 / 10 10 10 10 Hondo Muni Airport 85 66 84 66 / 20 10 20 20 San Marcos Muni Airport 85 68 84 68 / 20 10 10 10 La Grange - Fayette Regional 85 69 85 68 / 20 0 0 0 San Antonio Intl Airport 85 69 84 69 / 20 10 20 10 Stinson Muni Airport 85 69 85 69 / 20 10 10 10

EWX WATCHES/WARNINGS/ADVISORIES

None.