textproduct: Austin/San Antonio

KEY MESSAGES

- Threat for Severe Weather Increased to a Level 3 of 5 Risk over the Southern Edwards Plateau Late Tuesday Afternoon into Tuesday night; All Severe Hazards Possible

- Severe Weather Risk decreases to level 1 to 2 farther east into and towards the I-35 corridor Tuesday night; Main severe hazards would be large hail and strong winds

- Level 1 to 2 Risk for locally heavy rainfall and isolated flash flooding across the Southern Edwards Plateau and western Hill Country Tuesday night

- Drier weather pattern beyond Wednesday Morning; slightly cooler midweek behind Pacific front then warmer into and through the weekend

SHORT TERM

(Tonight through Tuesday night) Issued at 127 PM CDT Mon Mar 9 2026

A slow improvement of the fog, patchy drizzle, and low cloud ceilings entering early this afternoon. The rest of the afternoon should remain partly to mostly cloudy with more cloud breaks across portions of the Hill Country to the coastal plains. Speaking of the coastal plains, with the cloud breaks, there could be the opportunity for some isolated streamer showers, or even a stray thunderstorm, across our eastern most coastal plain counties this afternoon where slightly better daytime heating will likely occur. Rain is not expected elsewhere through this afternoon with slightly lower temperatures given thicker cloud cover. A southerly surface wind has returned and will slightly increase through this afternoon across the region. Weak upper level energy with small ripples within the flow aloft ahead of the parent upper level low across Northern Mexico to the west, arrives into tonight and could allow for some isolated to scattered showers and a few elevated storms to advance into the Edwards Plateau and our western areas tonight. Activity may persist into and through Tuesday morning and may advance a little more east with time; however activity could struggle getting past the US highway 281 corridor. Otherwise, anticipate a warm and humid night with returning low clouds and patchy fog. Most of Tuesday will otherwise remain mostly cloudy with afternoon highs peaking in the 70s and 80s.

Now on to the most impactful weather in the forecast. The parent upper level system approaches the region from the west into Tuesday evening. Regardless if it opens up into a trough or remains as an upper low, the overall dynamics for the system will be quite potent as it enters into our northwestern counties through the Southern Edwards Plateau. These dynamics provides stronger wind shear, both across the 0-6 km layer but also within the low-levels as well. The shear coupled with at least moderate instability (MLCAPE of 1500+ J/kg) from the late afternoon through the evening will support severe weather. The development of cells initially occur around or soon after 21/22Z across the Southern Edwards Plateau and perhaps west of the Rio Grande in Mexico. The storm mode initially at least would also lean on possible discrete supercells with all modes of severe weather possible. Expect the greatest threat for severe weather within the region to concentrate across this region. A few of these storms may be capable of producing a strong tornado (up to EF2 strength), 2+ inch diameter hail, and damaging winds up to 75 mph. As these storms advance farther eastward beyond dark, expect for the storms to congeal and trend evolve towards more of a linear mode aligning along the Pacific front. The storm intensities are quite likely to wane on the approach to and across the I-35 corridor and for points east. This is due to the decreasing instability over the region with the expectation for storms arriving late overnight into the early morning hours of Wednesday. Additionally, the Pacific front associated with this upper level system could undercut the ongoing storms and advances out ahead. A large swath of heavy rainfall is not anticipated with the progressive nature of the upper low and it's Pacific front, but strong to severe cells could produce a quick 1 to 3 inches in a short time, resulting in isolated flash flooding potential. This potential is highest in the Southern Edwards Plateau and Western Hill Country as well.

LONG TERM

(Wednesday through next Monday) Issued at 127 PM CDT Mon Mar 9 2026

Showers and storms could linger into the eastern half of the region during Wednesday morning before rain ends as drier air funnels in behind the Pacific front from Wednesday afternoon into Wednesday night. Modest cold air advection will be associated with the post- frontal northerly flow and results in slightly cooler temperatures from Wednesday night through Thursday. Wednesday and Thursday afternoons across our western areas could be dry enough to contend with possible fire weather conditions, but this hinges on how much wetting rain occurs with our approaching system.

The rest of the forecast through the weekend will remain rain free with a dry northwesterly flow aloft in wake of the departing upper level system. Friday through the day on Sunday will see light to moderate southerly winds as well. Temperatures warm during each subsequent day with Sunday seeing the highest daytime highs. We'll monitor the next front, which then could arrive as soon as Sunday night. However, this front looks to remain mostly a dry frontal passage.

AVIATION

(18Z TAFS) Issued at 127 PM CDT Mon Mar 9 2026

Low clouds continue for the I-35 sites and fog remains stubborn near the KSAT and KSSF terminals early this afternoon. However, we are seeing some signs of improvement and expect the fog to lift and cigs to rise back into MVFR this afternoon. Improvement back to VFR is expected by late afternoon as SCT-BKN clouds with bases near 4k AGL along with some mid-level clouds continue across the region. The I- 35 sites will quickly return back to low end MVFR around 04Z, the drop into IFR between 08-10Z. The lowest VSBYs look to occur near KSAT and KSSF and will mention a TEMPO group for 1/2SM FG between 10- 14Z. Conditions will be slow to improve tomorrow, but an increase in surface wind should bring about a faster improvement in the visibility compared to today. Out west at DRT, low clouds should erode over the next hour, with VFR expected after 19Z. We will continue to mention a PROB30 for -TSRA as some of the hi-res guidance does show some activity moving in from the west this evening. Low clouds and MVFR cigs should make a return to DRT around 13Z tomorrow.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 69 83 65 80 / 10 20 80 60 Austin Bergstrom Intl Airport 69 84 64 80 / 10 20 80 60 New Braunfels Muni Airport 69 84 64 81 / 10 10 80 50 Burnet Muni Airport 68 80 61 76 / 10 30 90 40 Del Rio Intl Airport 68 84 59 86 / 30 30 90 0 Georgetown Muni Airport 69 82 62 78 / 10 30 90 60 Hondo Muni Airport 67 83 60 84 / 20 20 80 20 San Marcos Muni Airport 69 84 64 81 / 10 10 70 60 La Grange - Fayette Regional 71 85 68 80 / 10 10 70 80 San Antonio Intl Airport 68 84 64 82 / 20 10 80 40 Stinson Muni Airport 69 85 65 84 / 20 10 80 40

EWX WATCHES/WARNINGS/ADVISORIES

None.