textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1225 AM CDT Wed May 13 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

(06Z TAFS) Issued at 1225 AM CDT Wed May 13 2026

VFR conditions are generally expected to prevail through the TAF period with some patchy fog and MVFR visibility developing early Wednesday morning near daybreak, mainly near HRL.

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 69 90 74 90 / 0 0 0 0 HARLINGEN 63 91 69 91 / 0 0 0 0 MCALLEN 68 94 72 93 / 0 0 0 0 RIO GRANDE CITY 67 93 70 94 / 0 0 0 0 SOUTH PADRE ISLAND 75 83 77 84 / 0 0 0 0 BAYVIEW/PORT ISABEL 69 87 73 88 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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