textproduct: Austin/San Antonio

KEY MESSAGES

Updated at 630 PM CDT Fri Sep 4 2026

- Low to medium (15-50%) rain and storm chances today into the weekend; a few heavy downpours possible.

- Elevated moisture levels and above average heat continues with heat indices possibly approaching advisory criteria over portions of the Coastal Prairies, I-35 Corridor and the Rio Grande Plains this weekend into all of next week.

SHORT TERM

(Tonight through Saturday night) Issued at 1233 PM CDT Fri Sep 4 2026

Mid level remnants of former TS Edouard are currently drifting WSW across the Austin metro area but the early day convection remains deep only over areas along and east of Highway 77 out to near I-45. Considerable mid and high level clouds closer to the broad circulation center covers much of Central TX and well into the Hill Country and San Antonio metro area with only some light sprinkles reaching the ground. The clouds will moderate today's highs considerably, but a degrading lower cloud deck over the Rio Grande Plains will still result in some areas climbing into the upper 90s to around 102.

An uptick in deeper convection is expected for areas mainly north of I-10 later today as some of the mid cloudiness burns off, but the overall PoP trends for today as compared to what we thought was going to happen in yesterday's forecast has come in much more conservative. While yesterdays hi-res runs showed multiple signals of heavy rain pockets over 5 inches, the heavy rain pockets are both more isolated and lower in magnitude. That's not today some lucky area can't get 2 inches, but overall the low QPF we have stuck with both yesterday and today speaks of the low overall coverage of rain expected without a surface focus and the presence of a still pretty dominant subtropical ridge aloft influencing the area. This drier trend means that we should see less evening and overnight activity, and that the overnight activity seen over the Houston forecast area this morning will not translate to our area getting anything tonight. Perhaps we'll see one or two nocturnal storms, but over such a sparse area, that it would not be worth mentioning in the forecast. The one exception is over the Coastal Prairies for early this evening.

As was seen this morning, the added cloudiness will again hold up minimum temperatures to well above normals. Tomorrows high temperatures will also be impacted, but to a lesser degree than they are being impacted today. Muggy overnight temperature will also be expected Saturday night with probably more low cloudiness forming. Again, Saturday's rain chances will be diurnally driven and will probably favor areas of the Hill Country, Rio Grande Plains, and over the Coastal Prairies, while relatively lower rain chances get stuck over the I-35 Corridor.

LONG TERM

(Sunday through next Friday) Issued at 1233 PM CDT Fri Sep 4 2026

By Sunday, the mid level shear is further suppressed and nudged SW by a TUTT Low reaching the TX coast. Some mid level dynamics are expected to spin up over the Coastal Bend, leading to a secondary wave of pooled mid-level moisture moving through the area. This wave of moisture should not have as much mid to high cloudiness to contaminate daytime rain chances, so we might just see our best rain chances overall to happen on daytime Sunday. Even if it plays out that way, we are only talking about most PoPs increasing to 20-30 percent versus most areas seeing 10-20 percent today through Saturday. And of course, the Coastal Bend is where PoPs are highest, so out SE CWA could see PoPs as high as 50 percent.

After Sunday, the moisture in the surface to mid levels remains elevated for several days, but not enough to generate much more than a few storms. This means we should continue to see some daytime convection but probably mostly associated with the sea- breeze and focused over eastern areas.

Yesterday's deterministic models held more optimism the pair of weak disturbances passing through would put a dent into the subtropical upper ridge. That now looks to be a slight outlier, as the past couple runs depict another round of days with upper highs from the mid 90s to near 102, and heat index values pushing close to borderline Heat Advisory conditions each day. The blended guidance maxes only fluctuated a degree or two so we'll stick with moderated highs one more day in keeping our more populated areas of the I-35 Corridor just shy of 100; a shift to favor the warmer MOS highs actually reaching 100 may happen in the next day or so, but we want to make sure the warming values are a trend and not just a wobble.

AVIATION

(00Z TAFS) Issued at 630 PM CDT Fri Sep 4 2026

VFR CIGs should continue for all I-35 TAF sites through the late evening hours. MVFR CIGs are possible for both KSSF and KSAT starting around 08Z and ending late morning. For KAUS CIGs should stay VFR throughout the period with southerly and at times VRB winds especially by sunrise before becoming more southeasterly in the afternoon. There are very isolated chances for showers tomorrow across KSSF and KSAT however chances are around 20 percent so have left them out of this forecast package for now. For KDRT expect VFR CIGs throughout the period with gusty east- southeasterly winds eventually calming down in the next few hours. Thereafter we should see winds around 5 to 10 knots through the remainder of the period.

PRELIMINARY POINT TEMPS/POPS

Austin Camp Mabry 76 97 76 97 / 10 10 10 20 Austin Bergstrom Intl Airport 76 97 75 97 / 10 10 10 30 New Braunfels Muni Airport 75 97 74 97 / 10 10 10 20 Burnet Muni Airport 73 95 73 95 / 10 10 10 20 Del Rio Intl Airport 78 99 77 97 / 10 20 10 10 Georgetown Muni Airport 75 96 75 97 / 10 10 10 20 Hondo Muni Airport 74 96 73 96 / 20 30 10 30 San Marcos Muni Airport 74 97 74 97 / 10 10 10 20 La Grange - Fayette Regional 76 96 76 96 / 20 20 10 40 San Antonio Intl Airport 76 97 77 97 / 10 10 10 30 Stinson Muni Airport 77 98 76 99 / 10 10 10 30

EWX WATCHES/WARNINGS/ADVISORIES

None.