textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1207 PM CDT Tue May 5 2026

Key Messages:

* Moderate to Major Heat Risk is expected for Wednesday, and Minor to Moderate heat risk is expected for Thursday.

* A cold front is expected Thursday into Friday. This will bring a low to moderate (20-50%) chance of rain of rain to Deep South Texas Thursday into Friday with a conditional chance of thunderstorms Thursday.

* Another weak front is possible early next week, but confidence is low a this time.

* There is a moderate risk of rip currents through tomorrow afternoon.

DISCUSSION

Issued at 1207 PM CDT Tue May 5 2026

Mid to upper-level high pressure remains just off the Northern Mexican Coast for the next few days. Due to increased warming and southerly surface flow, a hot and humid airmass is expected to remain over region the next two days, supporting potential record high temperatures and Moderate (level 2 of 4) to Major (level 3 of 4) Heat Risk on Wednesday. Minor (level 1 of 4) to Moderate Heat Risk is also possible on Thursday, but cloud cover is expected to increase as a cold front approaches the area, which will slightly lower daytime heating for Thursday. Conditions will also be breezy these days due to a tightened pressure gradient.

A cold front is expected to pass through the region Thursday evening into the overnight hours. Originally, it was uncertain whether the cold front would make it all the way through Deep South Texas or stall over the region. Today's NBM guidance seems to favor the scenario where the front passes completely through Deep South Texas sometime Thursday afternoon through evening, which will lower Friday's high temperatures into the upper 80s and concentrate rain chances to Thursday and Friday before drying up for the the weekend.

Rain chances should be low to moderate Thursday through Friday (20- 50%) with the best chances overnight Thursday into Friday. The Storm Prediction Center also has Deep South Texas under a general risk of thunderstorms for Thursday, though the threat is highly conditional on frontal timing and the strength of the capping inversion at the time of frontal passage. Current thinking is that if the front moves more slowly, the potential for thunderstorms will be higher due to increased instability due to daytime heating and rich moisture. If the front moves through more quickly, the potential for thunderstorms will be lower due to limited daytime heating, which is less likely to overcome the cap.

Temperatures are expected to warm back into the 90s for the weekend. Some models are also hinting that another weak frontal boundary could make its way through Deep South Texas early next week, but confidence is low at this point. If so, there may be a small uptick in rain chances (20-30%) Monday into Monday night. This frontal boundary isn't expected to cool temperatures much, if at all.

A moderate risk of life-threatening rip currents remains at area beaches through tomorrow night.

AVIATION

(18Z TAFS) Issued at 1207 PM CDT Tue May 5 2026

VFR conditions are expected at all airports. Ceilings will then lower to MVFR tonight around 00z to 01z and stay MVFR through the rest of the TAF period. Winds could become gusty this evening but will remain southeasterly.

MARINE

Issued at 1207 PM CDT Tue May 5 2026

A Small Craft Advisory is in effect today from noon until 10 pm. 20 kt winds with gusts up to 30 kts are expected both in the Bay and the nearshore Gulf waters. Conditions should improve tomorrow, but SCEC is still possible. Conditions should then improve and stay favorable by Thursday. There is a frontal passage expected which will change the wind direction to a northerly direction, but it isn't anticipated to have too much of an effect on wind speeds.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 77 94 77 92 / 0 0 0 20 HARLINGEN 75 97 74 91 / 0 0 0 20 MCALLEN 79 101 79 94 / 0 0 10 20 RIO GRANDE CITY 75 101 77 93 / 0 0 10 30 SOUTH PADRE ISLAND 77 85 77 83 / 0 0 0 10 BAYVIEW/PORT ISABEL 76 93 75 88 / 0 0 0 10

BRO WATCHES/WARNINGS/ADVISORIES

TX...None. GM...Small Craft Advisory until 10 PM CDT this evening for GMZ130-132- 135-150-155.