textproduct: Corpus Christi

KEY MESSAGES

Issued at 132 PM CDT Mon Sep 28 2026

- Temperatures will remain above normal through the first half of the week. A Heat Advisory may be needed Wednesday.

- 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 and/or Friday.

- Minor coastal flooding possible starting by mid-week.

DISCUSSION

Issued at 132 PM CDT Mon Sep 28 2026

Big changes are expected the latter part of this week and into the weekend with increasing rain chances and a cold front.

Heat remains a concern through Wednesday with above normal temperatures continuing under a persistent ridge of high pressure. By Wednesday, 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 which may warrant a Heat Advisory. Will continue to monitor trends.

Tuesday is now looking a little more active along the sea breeze due to increasing moisture and a weakness in the ridge aloft, mainly across the Victoria Crossroads. By Wednesday, the weakness shifts slightly southeast with the ridge becoming more dominant once again and rain chances lowering to 15-30%.

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.

A cold front associated with the mid/upper low is progged to move into N TX on Wednesday while a pre-frontal surface trough develops across S TX. Models indicate widespread showers and thunderstorms by Thursday as the surface trough provides low level moisture convergence and upper level moisture from the Pacific arrives leading to PWATs increasing to 2.2-2.5 inches. This is almost 2 standard deviations above normal and is conducive for heavy rainfall with flash flooding possible. This moisture will interact with the pre-frontal surface trough and/or outflow boundaries from the convection expected across the Hill Country. The main cold front is forecast to move into S TX Friday or Saturday with winds strengthening from the north and cooler temperatures for the weekend. 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 models have been differing from run to run on timing and just how far south the front goes before stalling.

Minor coastal flooding will be possible starting Tuesday as winds strengthen across the gulf waters. The P-ETSS indicates tide levels up to 1.8 feet above MSL for Tue-Thu and near 2ft by Friday during times of high tide. There is low confidence that water will reach the dunes due to swell periods of 7 seconds or less, and the moon phase will be approaching the 3rd quarter. In addition, the wind direction will play a role in how high tides get. If they are more southerly, then higher tides are less likely, but east to southeast winds would be more conducive. Will continue to monitor trends for any changes.

AVIATION

(18Z TAFS) Issued at 132 PM CDT Mon Sep 28 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 Tuesday at all TAF sites. Winds will remain light tonight, then strengthen Tuesday to 10-15 knots gusting to around 20 knots.

MARINE

Issued at 132 PM CDT Mon Sep 28 2026

A gentle to moderate (BF 3-4) east to southeasterly flow is expected to persist, along with seas between 2-3 feet, through Tuesday afternoon. Winds are forecast to increase to fresh to strong (BF 5- 6) by Tuesday night as low pressure deepens over West Texas. Small Craft Advisories may be needed by Tuesday night through Thursday. Isolated to scattered showers and thunderstorms expected Tuesday, then increasing to scattered to numerous by Thursday and Friday. Rain chances continue through the weekend.

PRELIMINARY POINT TEMPS/POPS

Corpus Christi 79 93 79 94 / 10 30 20 20 Victoria 74 97 76 97 / 10 50 30 30 Laredo 77 101 79 103 / 0 0 0 0 Alice 75 97 77 99 / 10 20 20 10 Rockport 79 91 80 92 / 20 50 20 20 Cotulla 76 100 78 102 / 0 0 0 0 Kingsville 76 95 78 97 / 10 20 20 10 Navy Corpus 82 90 82 90 / 20 30 30 20

CRP WATCHES/WARNINGS/ADVISORIES

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