textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 607 AM CDT Tue May 12 2026

Key Messages:

* Rain-free weather conditions with warmer than normal temperatures can be expected through next weekend.

* Heat Risk could begin building next weekend into the early parts of next week; widespread Moderate (Level 2 of 4) Heat Risk with pockets of Extreme (Level 3 of 4) Heat Risk is forecasted.

* There is a low-medium (20-40%) chance for showers and thunderstorms developing next week (Monday through Wednesday).

DISCUSSION

Issued at 1033 PM CDT Mon May 11 2026

Rain-free weather conditions along with warmer than normal temps can be expected through at least next weekend with high pressure in control, frontal boundaries well to our north, and a 588-591 dam heat ridge in place over Deep South Texas. We'll have to keep an eye out for next week and the potential for the weather pattern to become a bit more unsettled.

Multiple forecast and AI/ML models/ensembles are suggesting an increase in showers and thunderstorms next week in association with an approaching or nearby frontal system. Currently, we have low-medium (20-40%) chances for showers and thunderstorms in the Monday through Wednesday timeframe. Again, we will continue to monitor the trends on the chance for the pattern becoming a bit more unsettled next week. The Climate Prediction Center (CPC) has outlooked much of Texas including all of Deep South Texas under a medium (50-60%) chance for a wetter than normal pattern in it's 6-10 day outlook which covers May 17-21.

As mentioned earlier, temperatures will rune warmer than normal through the forecast period. High temperatures will generally range between the upper 80s to mid 90s across Deep South Texas. There could be a few upper 90s across the far western sections of our CWA (i.e. Zapata and Starr Counties). Overnight low temperatures will be in the 60s and 70s tonight through Thursday night before climbing into the mid 70s to lower 80s Friday night through next Tuesday night.

AVIATION

(12Z TAFS) Issued at 607 AM CDT Tue May 12 2026

VFR conditions will persist through the TAF period at all TAF sites. Northeasterly winds are expected to last through the TAF period at all TAF sites as well and should be light as well.

MARINE

Issued at 1033 PM CDT Mon May 11 2026

Generally favorable marine conditions will prevail through next weekend with low to moderate winds and seas. Moderate seas could begin developing Friday night through the weekend.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 88 68 89 68 / 0 0 0 0 HARLINGEN 87 64 89 64 / 0 0 0 0 MCALLEN 90 68 91 68 / 0 0 0 0 RIO GRANDE CITY 89 67 91 67 / 0 0 0 0 SOUTH PADRE ISLAND 81 73 81 75 / 0 0 0 0 BAYVIEW/PORT ISABEL 84 68 86 68 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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