textproduct: Austin/San Antonio

KEY MESSAGES

- Unsettled weather pattern continues through the middle of next week with daily shower and storm chances. Strong to marginally severe storms and locally heavy rains are possible most days.

- Well above average temperatures most days through the middle of next week, but cooler for this weekend.

SHORT TERM

(Tonight through Friday night) Issued at 1216 PM CST Thu Mar 5 2026

Breezy and moist south winds continue across South-Central Texas this afternoon as troughing expands across the western US. A few streams of mid-level moisture can be seen on WV and ALPW imagery ahead of this troughing. Isolated streamer and popup showers continue over the Coastal Plains into the I-35 corridor, but forcing there will remain weak throughout the day. As forcing increases out west, isolated showers and storms are forecast to form along the dry line in West Texas and atop the Serranias del Burro in Mexico. These should drift east to east-northeast into the Rio Grande Plains and Edwards Plateau late this afternoon into the evening. The 20-30 kt effective bulk shear, 1500-2000 J/kg MLCAPE, steep mid level lapse rates around 8 C/km in these areas may support a strong to severe thunderstorm maintaining strength for a few hours. Isolated large hail and damaging winds are the main concerns. Evening storms should weaken and dissipate overnight as conditions stabilize beneath warm mid-level air.

The mid/upper level trough continues to slosh east closer to our area Friday. This will induce low-pressure development over the Central Plains, bringing the dryline into our area Friday afternoon. Light streamer showers are possible with the moist and humid air ahead of the dryline Friday morning into the day. For Friday afternoon, the atmosphere over much of South-Central Texas along and ahead of the dry line shows similar levels of potential instability as today based on forecast sounding, suggesting another conditional and isolated severe threat. The main forcing will be to our north, and uncertainties in the cap strength result in a rather low confidence forecast regarding rain chances and coverage Friday. CAMs that do show deep convective development generally do so along the I- 35 corridor north of I-10. Large hail, damaging winds, and locally heavy rains would again be the main concern with these isolated storms.

LONG TERM

(Saturday through next Thursday) Issued at 1216 PM CST Thu Mar 5 2026

The long awaited split of the mid/upper trough over the Rockies into two components is forecast to occur by Saturday. Meridional flow behind the lead trough propels a cold front into South-Central Texas on Saturday, which stalls out Saturday night into Sunday just south of our area. While this occurs, the other portion of the trough reestablishes as a cut-off low over the Baja California.

A wide plume of moisture will push across Texas ahead of and along this stalling front. Both the NAEFS and ENS ensemble averages project PWAT values exceeding the 99th percentile over much of South- Central Texas through the weekend. The combination of the stalled front, robust mid-level moisture, and ripples of mid-level vorticity traversing our area provide a favorable pattern for several rounds of showers and thunderstorms over our area capable of locally heavy rainfall. While cooler air at the surface spreads behind the front, ensemble mean MUCAPE values in the 500-1500 J/kg range will continue to support showers and storms. The front should rebound north on Monday in the face of persistent moist southerly flow, and then midweek the cut-off low will likely rejoin westerly flow aloft and move across our area Wednesday. While these periods of rain are favored throughout the weekend into Wednesday, ensemble guidance has generally started to highlight Saturday afternoon through Sunday morning as a more conducive period for heavier rainfalls when convergence along the front is at its greatest. During this window, there is a 60-90% of at least 1 inch of rainfall for much of South- Central Texas. Broad totals above 2 inches have also increased in likelihood, with the latest model blend showing a 40-60% chance generally north of I-10. A final round of stronger storms and heavier rainfall has also been emerging on models Tuesday afternoon into Wednesday morning. Moderate instability and shear may allow for a few strong to severe storms, though heavier rains and potential flooding will likely be the primary impacts.

Temperatures stay warm heading into the weekend, but rains and cloudiness will help bring down temperatures over the weekend, most prominently during the daytime. Behind the cold front late Saturday into Sunday, temperatures may substantially lower under thick cloud cover and persistent rains. The latest model blend shows highs in the Hill Country, Edwards Plateau, and Austin area topping out in the 60s Sunday, but it would not be a surprise to see temperatures closer to the NAM in the 50s for much of the day. As the front pushes back north Monday, warmer air should return. Cooler air may arrive following the end of the rainy period midweek next week behind a cold front.

AVIATION

(18Z TAFS) Issued at 1216 PM CST Thu Mar 5 2026

High amplitude trough digging into the SW CONUS continues to tighten the surface pressure gradient and should maintain a tight gradient into Friday afternoon. The gusty winds as high as 30 knots in the afternoons should help keep the timing of MVFR CIGs mixing out to VFR fairly consistent each day with most CIGs getting into VFR before 19Z. Tonight's return of MVFR CIGs should arrive near I-35 again by 05Z or 06Z and near DRT by 09Z or 10Z. There is a brief and low potential for convection, west of DRT around 02Z, and another potential for low impact light showers or sprinkles around I-35 in the late morning hours Friday.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 68 84 68 80 / 20 50 50 90 Austin Bergstrom Intl Airport 67 84 68 82 / 10 50 40 90 New Braunfels Muni Airport 66 83 68 82 / 10 40 30 80 Burnet Muni Airport 66 81 65 76 / 10 60 40 90 Del Rio Intl Airport 66 89 67 80 / 30 10 20 80 Georgetown Muni Airport 66 83 67 79 / 10 50 50 90 Hondo Muni Airport 65 84 65 82 / 20 40 30 80 San Marcos Muni Airport 66 85 67 82 / 10 40 40 80 La Grange - Fayette Regional 69 86 69 84 / 0 30 30 70 San Antonio Intl Airport 68 82 69 82 / 20 40 50 80 Stinson Muni Airport 69 85 70 83 / 20 40 40 70

EWX WATCHES/WARNINGS/ADVISORIES

None.