textproduct: Corpus Christi

KEY MESSAGES

Issued at 157 PM CDT Wed Sep 30 2026

- There is a Moderate Risk for excessive rainfall for the western half of S TX and a Slight Risk for the eastern half on Thursday. There is a Slight Risk for the western areas on Friday.

- Heavy rainfall and flash flooding threat increases Thursday and Friday and a Flash Flood Watch is in effect beginning Thursday morning through Friday evening for portions of South Texas.

- Marginal Risk of Severe Thunderstorms Thursday across most of South Texas with damaging winds being the main threat.

- Minor coastal flooding possible early next week.

DISCUSSION

Issued at 157 PM CDT Wed Sep 30 2026

Thursday and Friday are still shaping up to be wet with heavy rainfall and the potential for flash flooding. High rain chances remain in the forecast through the weekend with a cold front possibly stalling along the Texas coast by Friday night into Saturday. There remains a lot of uncertainty with regard to the cold front's timing, strength, and where it will ultimately stall across S TX.

A long wave mid/upper level trough with a cut-off low centered over the Desert SW, will continue to slowly move east-southeast through the period. Deeper moisture is already advecting across S TX from the gulf in the low and mid levels with PWATs already around 2.2 inches. The low will also tap into mid/upper level Pacific moisture from the remnants of Polo with PWATs progged to increase to 2.4-2.5 inches with some models indicating 2.7 inches moving across S TX on Thursday. This is well above normal for this time of year.

This deep moisture combined with a developing surface trough over S TX, and embedded upper level short waves tracking northeast ahead of the main low, will lead to a high chance of showers and thunderstorms across the region Thursday. The highest chances up to 90% are forecast for the Brush Country and Rio Grande Plains to 40% along the coastline. There is a Marginal Risk of severe thunderstorms on Thursday. Some storms may become strong to severe with wind damage expected to be the main threat.

The high chance of widespread convection will continue through Friday as the upper low draws nearer to S TX and brings a cold front to the area. The cold front is forecast to move into the Rio Grande Plains and Brush Country on Friday and possibly stall somewhere along the coast line Friday night into Saturday morning. There remains uncertainty as to the timing, strength and just how far southeast the cold front tracks. Where ever the front stalls will be the main focus for the heaviest rainfall and highest risk for flash flooding. For now, it looks like it will stall Friday night along the coast, then push off the coast by Sunday. A second re-enforcing cold front is possible by Monday with winds strengthening from the northeast and maintaining the cooler temperatures across S TX. The upper low is forecast to finally exit to the east with drier conditions expected next week.

Temperatures are tricky for Thursday. With the increasing clouds/rain, the max temps are expected to be slightly cooler than today. However, if less cloud cover develops, this will allow higher temps across the area which would combine with the high humidity and lead to heat indices up to 110-112 across the eastern CWA. Will monitor trends for Heat Advisory conditions Thursday. Cooler temperatures are expected Friday and into next week.

Minor coastal flooding is a possibility at times during high tide through early next week, especially Monday due to strengthening northeast winds across the gulf waters behind the second cold front.

AVIATION

(18Z TAFS) Issued at 157 PM CDT Wed Sep 30 2026

The chance for showers and thunderstorms will increase across the LRD, COT, and VCT TAF sites overnight, then spreading east to CRP and ALI Thursday morning. Widespread convection is expected Thursday through Friday and likely through the weekend. PROB30 groups have been introduced to the TAFs to address the potential for storms and MVFR/IFR conditions. Outside of the convection, conditions are expected to be MVFR/VFR. Winds will be light from the south tonight. Prevailing wind speeds 10-20 knots gusting to around 25 knots are possible Thursday. However, stronger gusts maybe associated with the convection.

MARINE

Issued at 157 PM CDT Wed Sep 30 2026

A moderate to fresh (BF 4-5) south to southeast flow is expected tonight into Thursday morning. Small Craft Should Exercise Caution tonight. Winds weaken to a gentle to moderate (BF 3-4) onshore breeze Friday and shift to the east to northeast Friday night or Saturday as a cold front approaches the coastal waters. Low to medium chance for showers and thunderstorms expected tonight through Thursday, then increasing to a high chance Thursday night through the weekend.

PRELIMINARY POINT TEMPS/POPS

Corpus Christi 80 94 77 89 / 30 60 80 90 Victoria 77 97 74 90 / 40 80 90 90 Laredo 79 96 74 85 / 30 80 80 90 Alice 77 97 74 89 / 30 80 90 90 Rockport 80 93 77 90 / 40 60 80 90 Cotulla 78 93 73 83 / 30 90 90 80 Kingsville 79 96 76 90 / 30 70 80 90 Navy Corpus 83 91 81 88 / 40 40 80 90

CRP WATCHES/WARNINGS/ADVISORIES

TX...Flood Watch from Thursday morning through Friday evening for TXZ229>232-239>244.

Heat Advisory until 7 PM CDT this evening for TXZ241>244-342>344.

GM...None.