textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 633 AM CDT Sat Aug 29 2026

- Hot, mainly dry, and at times breezy conditions will continue through next week.

- Widespread Major (Level 3 of 4) with areas of Extreme (Level 4 of 4) Heat Risk is expected through next week.

- Worsening drought conditions are expected to continue due to the combination of very hot temperatures, antecedent dry conditions, and very high evaporation rates.

- Despite mainly dry conditions expected and drought conditions to continue, there will be chances for sea breeze showers and thunderstorms at times through next week.

DISCUSSION

Issued at 1043 PM CDT Fri Aug 28 2026

Hot, mainly dry, and at times breezy conditions will continue through next week across Deep South Texas and the Rio Grande Valley. The broad and strong 591-594 dam sub-tropical heat dome that recently resulted in a heat wave with record-breaking temperatures across parts of the Southwestern U.S. and Southern Plains is on the move eastward this weekend into next week or into the early part of September. The eastern two-thirds of the country from the Southern Plains and specifically over the Ohio Valley and East Coast will experience an uptick in temperatures and Heat Risk in the days ahead. Despite the ridge shifting east and being slightly weaker than prior days, the heat ridge centered to our north- northeast will still yield hotter than normal temperatures (though not quite record-breaking as prior days) through the forecast period across Deep South Texas.

High temperatures will continue to range near 100F degrees near the coast to the mid 100s further inland or west, while low temperatures will remain in the 70s to lower 80s. The combination of the high temperatures and humidity levels will result in a continuation of widespread Major (Level 3 of 4) to pockets or areas of Extreme )Level 4 of 4) Heat Risk through next week. Peak heat indices will continue to range between 105-115F degrees (highest closer to the coast) through next week.

While it will be mostly dry through the forecast period and drought concerns will remain, the large-scale and mid-upper level pattern will favor a east-southeasterly flow, which at times could trigger some sea breeze convection (showers and thunderstorms).

AVIATION

(12Z TAFS) Issued at 633 AM CDT Sat Aug 29 2026

Light winds and mostly clear skies prevail across Deep South Texas early this morning. Light east to southeast winds are expected to increase to around 15 knots later this morning into the afternoon. Winds are forecast to gradually decrease this evening into tonight. Given the low chance of sea-breeze showers and thunderstorms today, will continue not to mention convection at this time. VFR conditions are expected for the next 24 hours.

MARINE

Issued at 1043 PM CDT Fri Aug 28 2026

Favorable marine conditions are expected to continue through next week with low to moderate seas (1 to 3 foot wave heights) and light to moderate southeasterly winds.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 97 80 97 81 / 10 0 10 0 HARLINGEN 99 76 100 77 / 10 0 20 0 MCALLEN 103 80 103 81 / 10 10 10 0 RIO GRANDE CITY 103 78 103 79 / 0 0 0 0 SOUTH PADRE ISLAND 89 81 89 82 / 10 10 10 0 BAYVIEW/PORT ISABEL 95 78 96 79 / 10 0 10 0

BRO WATCHES/WARNINGS/ADVISORIES

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