textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 652 PM CDT Sun Oct 4 2026

- Additional bands of moderate to heavy rainfall is expected today and tomorrow, especially for areas close to the coast.

- There is a Moderate (level 3 of 4) Risk of Excessive Rainfall for coastal counties this afternoon, and a Slight (level 2 of 4) Risk of Excessive Rainfall tomorrow.

- Rain chances overall decrease after Tuesday, but continue along the sea breeze through the end of the week.

- Temperatures should be closer to seasonal levels this upcoming week.

- There is a high risk of rip currents at area beaches through tomorrow with the potential for tidal run-up.

DISCUSSION

Issued at 1259 PM CDT Sun Oct 4 2026

A stalled frontal boundary and a coastal trough remain just offshore the lower Texas Coast, which is providing the atmospheric support along with deep tropical moisture for heavy bands of widespread shower and thunderstorm activity throughout eastern Deep South Texas the rest of today and tomorrow. The Weather Prediction Center has placed most of Cameron, Willacy, and Kenedy Counties under a Marginal Risk (level 3 of 4) for Excessive Rainfall the rest of today as rain continues to move onshore along the stalled front. Further west, there is a Slight and Marginal Risk for this afternoon.

Rain may somewhat diminish this evening in overall coverage, but additional bands of showers and thunderstorms are expected to develop overnight and continue moving onshore tomorrow morning. This could lead to heavier rainfall totals and additional flooding concerns tomorrow, especially in the early morning hours for urban areas close to coast, such as Brownsville and South Padre Island. The Weather Prediction Center maintains the Coastal Counties in a Slight (level 2 of 4) Risk of Excessive Rainfall tomorrow, with Marginal Risk for areas east of I-69C. Convection should become more scattered throughout the day tomorrow as the front moves further offshore, but the potential for localized flooding in some areas still exists, especially for areas that have already received higher rainfall totals. Chances for rain along the immediate coast will remain high (80-90%) continuing Tuesday, but chances for Excessive Rainfall significantly diminish. Low to moderate chances continue for areas further west throughout Deep South Texas.

Most ares should receive another 2 to 4 inches of rain between now and Tuesday. Some areas (especially closer to the coast) could see totals as high as 5 to 7 inches between now and Tuesday that receive heavier showers and thunderstorms.

For the remainder of the week, moderate diurnal rain chances continue each day along the sea breeze through Friday as troughing continues over the Gulf and the atmosphere remains unsettled. Conditions look drier, with low rain chances for next weekend. Temperatures are expected to be closer to seasonal, with highs in the upper 80s/lower 90s for most of the week. However, there is a still Mild (level 1 of 4) Heat Risk due to high levels of humidity.

There is a high risk of rip currents at area beaches through tomorrow, with longshore currents expected as well with northeasterly coastal winds. There could also be some tidal run-up around high tide with elevated surf.

We are monitoring a medium (40%) chance for Tropical Development in the Southwest Gulf over the next 7 days. In the wake of coastal troughing, a broader area of low pressure could form to the south, closer to the Bay of Campeche. It is too early to determine what (if any) impacts could affect Deep South Texas. Keep checking the forecast for the latest updates.

AVIATION

(00Z TAFS) Issued at 652 PM CDT Sun Oct 4 2026

Predominantly MVFR ceilings are forecast to persist through the period, with brief periods of IFR conditions possible. Scattered showers and thunderstorms are forecast to continue through the evening, with activity decreasing through the early morning. Additional showers and thunderstorms are likely by late morning or early afternoon Monday.

MARINE

Issued at 1259 PM CDT Sun Oct 4 2026

Unsettled weather and adverse marine conditions are expected to continue through early this week in response to abundant moisture content and coastal troughing. A Small Craft Advisory remains in effect for the northern Gulf waters through 1 PM Monday. Expect elevated winds and seas, along with reduced visibility, within any showers or thunderstorms.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 77 86 75 87 / 70 90 80 80 HARLINGEN 72 86 71 89 / 80 90 70 60 MCALLEN 74 86 73 90 / 80 70 60 40 RIO GRANDE CITY 72 86 72 90 / 70 70 30 20 SOUTH PADRE ISLAND 80 85 79 85 / 80 90 90 90 BAYVIEW/PORT ISABEL 76 87 75 88 / 80 90 90 80

BRO WATCHES/WARNINGS/ADVISORIES

TX...High Rip Current Risk through Monday evening for TXZ451-454-455.

GM...Small Craft Advisory until 1 PM CDT Monday for GMZ135-155-175.