textproduct: Corpus Christi

KEY MESSAGES

Issued at 1250 AM CDT Thu Oct 1 2026

- Flash flood watch in effect Thursday afternoon through Friday. Heavy rain expected at times across all of South Texas.

- Marginal risk of severe weather Thursday and Thursday night. Strong winds are the primary threat.

DISCUSSION

Issued at 1250 AM CDT Thu Oct 1 2026

The remnants of hurricane Polo have merged with a deep trough over the western US and a cut-off low is not prominent over Colorado and New Mexico. At the surface, a cold front is developing associated with this system and will push eastward over the next couple of days. There is still considerable uncertainty in how exactly the rain plays out and how quickly the front moves through. The probability of a morning round of convection appears to be decreasing based on current radar/satellite trends and how models are initializing. Most high res models have either given up on the morning line completely or at least backed off on how much convection there will be. That said, will keep mainly low end (20- 30%) pops for the morning with the exception of western parts of Webb and LaSalle county where things could start ramping up a bit earlier. The best potential for convection will be in the afternoon and overnight hours today and tonight with daytime heating and the mid-level low/trough moving closer. Regardless of when and where the rain occurs, with PWAT values nearly off the charts, the rain will fall very fast and heavy when it falls. PWAT value on the 18Z CRP sounding was 2.41", down a bit to 2.28" at the 00Z sounding. These are well above the 90th percentile in climatology and around the daily Max values. CRP almost certainly tops the current max value for tomorrow which is an outlier low record of 2.09". These high moisture levels are capable of producing rainfall rates 2-3"/hr, with isolated cells producing even higher rates. Probabilities of 48 hour rainfall through Friday over 3" are moderate to high over the western portions of the area, but not out of the question east with any given slow-moving storm capable of dumping that much.

The forecast struggle does not end after the Thursday/Thursday night rains, as the convergence line (stalled boundary) is likely to set up near the coast and keep rain chances going through the weekend, potentially into early next week, but this would be mainly along the immediate coast and into the marine areas. We also will see a couple of tropical waves move through the Gulf further enhancing moisture. Bottom line, it's going to rain...potentially a lot...and the forecast is still pretty tricky.

Taking a moment to talk temperatures, today is tricky...but with the lower probability of a morning round of convection, temps will likely once again be in the mid and upper 90s for most of the area. If convection begins earlier, this could certainly fall with some areas not getting out of the 80s. Speaking of 80s...it looks like a lot of highs in the 80s for the foreseeable future, finally getting back to normal or slightly below.

AVIATION

(06Z TAFS) Issued at 1250 AM CDT Thu Oct 1 2026

A mix of VFR and MVFR are expected throughout this TAF cycle with showers and thunderstorm impacting all sites at some point. The best shot for morning convection will be at LRD and COT with the eastern sites expecting to begin firing up in the afternoon. Winds will remain gusty for most of this forecast with some sites getting under 12 knots for the last few hours.

MARINE

Issued at 1250 AM CDT Thu Oct 1 2026

A moderate to fresh (BF 4-5) south to southeast flow will continue this morning. Small craft should exercise caution tonight. Winds weaken to moderate levels this afternoon, and weaken further to gentle levels friday, shifting to the north behind a weak boundary. There will be a low to medium chance for showers and storms today, increasing tonight through the weekend.

FIRE WEATHER

Issued at 1250 AM CDT Thu Oct 1 2026

No significant fire weather concerns are anticipated through the period. Increasing moisture will bring widespread showers and thunderstorms starting today through the weekend. Heavy rainfall and flash flooding will be possible across all of South Texas, with widespread wetting rainfall expected to limit fire weather concerns through the latter half of the week.

PRELIMINARY POINT TEMPS/POPS

Corpus Christi 94 77 89 75 / 60 80 90 70 Victoria 97 74 90 71 / 80 90 90 50 Laredo 96 74 85 71 / 80 80 90 90 Alice 97 74 89 71 / 80 90 90 70 Rockport 93 77 90 75 / 60 80 90 70 Cotulla 93 73 83 70 / 90 90 80 90 Kingsville 96 76 90 73 / 70 80 90 70 Navy Corpus 91 81 88 79 / 40 80 90 80

CRP WATCHES/WARNINGS/ADVISORIES

TX...Flood Watch from 7 AM CDT this morning through Friday evening for TXZ229>232-239>244.

GM...None.