textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1012 PM 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 remains a low-medium (20-40%) chance for showers and thunderstorms developing next week (Monday through Wednesday).

DISCUSSION

Issued at 1012 PM CDT Tue May 12 2026

Rain-free weather conditions along with warmer than normal temps can be expected through early next week 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. We continue to have low- medium (20-40%) chances for showers and thunderstorms in the Monday through Wednesday timeframe. Again, we'll continue to monitor the trends on the chance for the pattern becoming a bit more unsettled next week. The Climate Prediction Center (CPC) continues to have 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 18-22.

As mentioned earlier, temperatures will run 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 Wednesday night.

AVIATION

(00Z TAFS) Issued at 555 PM CDT Tue May 12 2026

Through 00z Thursday....VFR conditions are expected to prevail through the 00z TAF cycle. There could be a brief period of MVFR mist/low stratus early Wednesday morning due to the combination of calm winds and elevated levels of low level moisture.

East-northeast winds 5-10 kts this evening will trend towards light and variable to calm tonight. Light and variable to calm winds Wednesday morning will pick up out of the east-northeast with speeds between 5-10 kts mid morning to early afternoon.

MARINE

Issued at 1012 PM CDT Tue May 12 2026

Generally favorable marine conditions will prevail through Thursday with low to moderate winds and seas. However, more adverse (i.e. Small Craft Exercise Caution) conditions could develop Friday through the weekend and into the early parts of next week. A brief period of high end SCEC to low end Small Craft Advisory conditions is possible Sunday night, in response to breezy/windy conditions from an enhanced pressure gradient.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 68 89 69 90 / 0 0 0 0 HARLINGEN 64 89 63 91 / 0 0 0 0 MCALLEN 68 91 68 94 / 0 0 0 0 RIO GRANDE CITY 67 91 67 93 / 0 0 0 0 SOUTH PADRE ISLAND 74 81 75 83 / 0 0 0 0 BAYVIEW/PORT ISABEL 68 85 69 87 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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