textproduct: Austin/San Antonio

KEY MESSAGES

- A more humid and unsettled weather pattern in place through the upcoming week with daily rain and thunderstorm chances

- Several opportunities for isolated to scattered strong to severe thunderstorms and locally heavy rain from weekend into early next week; Sunday is day with highest confidence for areas along and north of I-35 and highway 90.

SHORT TERM

(Today through Friday) Issued at 1248 AM CDT Thu Apr 9 2026

A persistent light to moderate southeasterly low-level flow will continue across the region through the end of the work week with surface high pressure positioned from the Mid-Atlantic coast into the northeastern Gulf. This onshore flow will advect in a more humid airmass across the region, with PWATs increasing from near seasonal average yesterday (Wednesday) to above average levels (70-90% for this time of year) for the rest of the work week. Scattered to numerous showers along with some non-severe thunderstorms will be forecast today through Friday. This is due to increased upper level support as a shortwave moves into and across the southern half of our region from Central Mexico. This humid, onshore advection regime could also allow for coastal activity, with some enhancement from the sea breeze to enter our region as well. While the highest rain and storm chances should peak during the maximum heating of the day, chances will linger into tonight and Friday night as well. The deep layer shear is weak and instability levels will remain limited, keeping the chances for severe weather lower on these days. However, any slower moving cells could be able to produce isolated locally heavy downpours where a quick 1 to 3 inch rain could fall. Gusty winds to 40 mph could occur with stronger activity as well.

Temperatures will continue to run near to slightly above average. The humid conditions will result to the return of low clouds, with patchy fog, from the overnight into each morning. A mostly cloudy sky otherwise trends through the period.

LONG TERM

(Friday night through Wednesday) Issued at 1248 AM CDT Thu Apr 9 2026

Longwave troughing establishes across the Southwestern CONUS from this weekend through at least early next week. The influence from this trough will result in the development and increase in the southwesterly flow aloft across the state. A dryline boundary will establish and sharpen over West Texas into the higher terrain of Mexico with time as well. Embedded within the southwesterly flow aloft will be the occasional shortwave. While our region would remain very humid featuring well above average PWATs, expect area rain and storm chances to peak just in advance of these features where the forcing maximizes.

From Saturday into Saturday night, activity should primarily concentrate northwest of our region for the Midland and San Angelo CWAs, closest to the dryline and the better forcing with the shortwave's orientation. This should be where the severe weather potential would be the highest. The risk could see isolated cells extend as far south as portions of the Southern Edwards Plateau, as indicated on the latest Day 4 SPC convective outlook. Capping may be a limiting factor elsewhere as areas get farther away from the forcing of the shortwave, but the continued warm air advection could overcome, providing more scattered shower and storm activity, best along and to the east of the I-35 corridor.

Another embedded shortwave within the southwest flow looks to become a little closer, providing slightly better lift to the region, for Sunday through Sunday night. This better forcing should also coincide with the overlap of pooling moderate to strong instability and strengthening bulk shear vectors. This yields to the risk of some isolated to scattered severe thunderstorms, with a best focus along/north of the I-35 and highway 90 corridor as the SPC day 5 convective outlook highlights. Rainfall rates could become intense enough within these storms at times where an isolated risk for flash flooding also will exist. This is highlighted again within the WPC excessive rainfall outlook for this time range.

The region will remain under a southwesterly flow into the middle of next week as the main trough axis takes it's time before advancing into the Central Plains sometime around Wednesday. A daily rain and storm chance will persist across the area and much of Texas during this time, but the greatest rain along with severe weather risk would likely concentrate mainly along/east of the dryline and then with the front from the parent system as it overtakes the dryline boundary. This concentrates more across Central Texas early week before the front approaches our region closer to midweek as the parent trough slides east.

Temperatures remain slightly above average with the afternoon highs in the low to mid 80s and overnight lows in the mid 60 and low 70s across the majority of the area. Expect for clouds to remain more prevalent than sunshine with the moist airmass in place.

AVIATION

(12Z TAFS) Issued at 538 AM CDT Thu Apr 9 2026

IFR CIGs are settling in around SAT/SSF and could briefly reach DRT and AUS in the next couple hours or so. Light rain echoes are beginning to for south of San Antonio, but it looks like it will be a slow evolution for this activity to begin having impacts at the 4 airports. Closer to 00Z when a mid level shortwave is close enough to increase coverage and intensity we have some PROB30 groups running into the evening. The presence of precipitation could impact when CIG categories improve this afternoon and deteriorate again this evening. The continued increase in moisture from precipitation will probably lead the the CIGs falling into the IFR category faster late tonight and possibly lasting into midday Friday.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 81 65 80 66 / 40 40 50 20 Austin Bergstrom Intl Airport 82 65 80 66 / 40 40 60 20 New Braunfels Muni Airport 81 65 80 66 / 50 50 60 20 Burnet Muni Airport 78 63 78 63 / 20 30 50 20 Del Rio Intl Airport 79 65 80 66 / 40 40 30 50 Georgetown Muni Airport 80 64 80 65 / 20 30 50 20 Hondo Muni Airport 80 64 79 65 / 50 50 70 20 San Marcos Muni Airport 81 65 80 66 / 50 50 60 20 La Grange - Fayette Regional 82 66 81 67 / 40 30 60 20 San Antonio Intl Airport 80 66 80 66 / 50 60 70 20 Stinson Muni Airport 81 67 80 67 / 60 50 70 20

EWX WATCHES/WARNINGS/ADVISORIES

None.