textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1102 PM CDT Thu Oct 1 2026

- Cooler and wetter conditions are expected into early next week due to a frontal passage and a multi-day rainfall event.

- Another round of thunderstorms and heavy rain is likely Friday afternoon.

- Isolated flash flooding will remain a concern through the weekend, especially in areas that have already received several inches of rain.

DISCUSSION

Issued at 1102 PM CDT Thu Oct 1 2026

Heavy rainfall with pockets of flash flooding will continue to be a concern through the weekend and into early next week. The latest radar estimates depict widespread rainfall accumulations of 1-3 inches across the central portion of the CWA, with estimates of 6-8 inches over southeastern Starr county today. These portions of Starr, Hidalgo, Brooks, Jim Hogg, and Kenedy counties will likely be more susceptible to flooding over the coming days.

A cluster of showers, thunderstorms, and light to moderate stratiform rain across most of Deep South Texas this evening will likely linger overnight, gradually transitioning to mostly stratiform rain through the early morning. The bulk of the convective models depict most of the activity diminishing by mid morning, before another round of scattered to widespread showers and thunderstorms develop Friday afternoon.

The heaviest rainfall Friday will most likely along and west of I-69C/US-281, with widespread accumulations of 1-2 inches forecast, with isolated amounts up to 4-6 inches possible.

A cold front is forecast to move through the area Friday evening into early Saturday morning. In the wake of the front, an overrunning pattern looks to set up as southeasterly mid-level flow continues to advect warm moist air from the Gulf into the region. This will likely support widespread stratiform rain, with generally light to moderate rainfall across much of the area, though some heavier bands may develop, especially along the coast. Widespread daily rainfall amounts of 1-2 inches are forecast Saturday and Sunday.

Rain chances across the area begin to decrease early next week, however elevated rain chances will likely persist along the coast, with the potential for coastal troughing or a coastal low to develop off shore.

AVIATION

(00Z TAFS) Issued at 634 PM CDT Thu Oct 1 2026

Ongoing convection across portions of Deep South Texas is expected to impact TAF sites this evening and overnight. A slow moving line of thunderstorms west of MFE is forecast to move over the airfield later this evening, resulting in MVFR to IFR conditions. Overnight, these thunderstorms are forecast to weaken, likely resulting in light to moderate rain through the early morning.

BRO and HRL are forecast to remain VFR through the evening, with showers and thunderstorms developing around the airfields overnight into the morning.

Conditions may briefly improve across the area late Friday morning, however additional showers and thunderstorms are forecast to develop Friday afternoon.

MARINE

Issued at 1102 PM CDT Thu Oct 1 2026

Light to moderate winds and moderate seas are forecast through the weekend, with winds and seas likely increasing early next week. Light southeasterly winds are forecast to shift northeasterly Friday evening as a cold front moves through the area. Rain chances remain elevated through early next week, with showers and thunderstorms likely through the weekend.

Small Craft Should Exercise Caution headlines or Small Craft Advisories may be needed early next week.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 80 94 77 91 / 50 60 60 80 HARLINGEN 75 95 74 92 / 60 60 60 80 MCALLEN 78 94 76 92 / 70 70 90 80 RIO GRANDE CITY 76 90 74 89 / 90 70 80 80 SOUTH PADRE ISLAND 82 88 80 87 / 40 50 70 90 BAYVIEW/PORT ISABEL 79 92 76 90 / 40 50 70 90

BRO WATCHES/WARNINGS/ADVISORIES

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