textproduct: Corpus Christi

KEY MESSAGES

Issued at 133 PM CDT Tue Sep 29 2026

- Temperatures will remain above normal through Wednesday and a Heat Advisory may be needed.

- Heavy rainfall and flash flooding threat is increasing for the latter part of this week and a Flash Flood Watch may be needed for Thursday night through Friday night when the heaviest rainfall is expected. 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.

- There is a Marginal Risk of severe thunderstorms on Thursday for the Rio Grande Plains and western Brush Country.

DISCUSSION

Issued at 133 PM CDT Tue Sep 29 2026

Model runs continue to show heavy rainfall the latter part of this week and into the weekend as a cold front approaches S TX on Friday and possibly stalls Friday night into Saturday along the coast. There remains a lot of uncertainty with regard to the cold front's timing, strength, and if it will stall across S TX.

Ahead of this rain event, heat remains a concern through Wednesday with above normal temperatures continuing under a ridge of high pressure. The ridge axis is forecast to slowly move east across the area through the day. Warm air advection and higher RH values may lead to heat indices around 110 for more than a couple of hours across the eastern 2/3rd of S TX Wednesday afternoon, which may warrant a Heat Advisory. Will continue to monitor trends. Slightly cooler temperatures are expected beginning Thursday with increased clouds/rain, then even cooler behind a cold front by the end of the week with highs in the 80s area-wide and lows in the upper 60s to 70s.

A long wave mid/upper level trough is progged to deepen as it tracks east-southeast across the western U.S. and approaches West Texas by mid week. This will strengthen the low level winds across S TX and usher deeper moisture across the area from the gulf in the low and mid levels. The low will also tap into mid/upper level moisture from the remnants of Hurricane Polo in the Pacific over the next couple of days. PWATs are progged to increase to 2.2-2.4 inches beginning Wednesday and as high as 2.5 inches Thursday. This deep moisture combined with embedded short waves tracking northeast ahead of the long wave trough, will lead to a 20-35% chance of showers and thunderstorms across mainly the Victoria Crossroads on Wednesday. Widespread convection is expected across S TX by Thursday as the upper trough approaches from the west and a weak prefrontal surface trough develops over S TX.

A cold front associated with the upper trough is forecast to move into S TX Friday and possibly stall somewhere across S TX Friday night into Saturday morning. If the cold front stalls anywhere in S TX, that will be a focus for the heaviest rainfall and possible flash flooding. There remains uncertainty with the cold front's timing, strength and how far south it progresses. For now, it looks like it will stall Friday night along the coast, then push off the coast by Sunday with winds strengthening from the north and cooler temperatures advecting into S TX. Medium rain chances continue through the weekend as the upper low slowly tracks east across TX.

Confidence is moderate to high with respect to increasing rain due to the upper low and abundant deep moisture. However, confidence with respect to the cold front remains low as model solutions continue to differ from run to run on timing and just how far south the front goes before stalling.

AVIATION

(18Z TAFS) Issued at 133 PM CDT Tue Sep 29 2026

VFR conditions are expected to prevail through most of the TAF cycle. However, brief MVFR VSBY and/or CIGs will be possible after 09Z through mid morning Wednesday at LRD, COT and VCT TAF sites. Rain chances increase across the VCT area this afternoon and again Wednesday morning. A PROB30 group has been introduced to the VCT TAF to address the potential. Winds will be light from the south tonight. Slightly stronger winds are expected Wednesday with speeds 10-20 knots gusting to around 25-30 knots.

MARINE

Issued at 133 PM CDT Tue Sep 29 2026

A gentle to moderate (BF 3-4) southeasterly flow is expected tonight into Wednesday morning along with seas between 2-3 feet. Winds are forecast to increase to fresh to occasionally strong (BF 5-6) flow by Wednesday evening as low pressure deepens over West Texas. Small Craft Advisories may be needed by Wednesday night. Winds weaken to a moderate onshore breeze Friday and shift to the east to northeast Friday night or Saturday as a cold front moves across the coastal waters. Low rain chances expected tonight through Wednesday, then increase to a high chance Wednesday night through the weekend.

PRELIMINARY POINT TEMPS/POPS

Corpus Christi 79 94 80 93 / 20 20 20 60 Victoria 76 97 77 96 / 20 30 40 70 Laredo 79 103 80 98 / 0 0 30 80 Alice 76 99 78 97 / 10 10 10 80 Rockport 80 92 81 92 / 30 20 40 50 Cotulla 77 102 78 94 / 0 10 40 90 Kingsville 78 97 79 96 / 10 10 10 70 Navy Corpus 83 91 83 90 / 30 20 30 50

CRP WATCHES/WARNINGS/ADVISORIES

TX...None. GM...None.