textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 517 PM CDT Fri Sep 25 2026

- Low to moderate (20 to 40%) sea breeze shower and thunderstorm chances continue this afternoon.

- Conditions will be dryer this weekend, but low to moderate rain chances will resume again on Monday and continue through next week.

- Moderate (level 2 of 4) to Major (level 3 of 4) Heat Risk continues through the weekend. By early next week, Major to Extreme (level 4 of 4) Risk returns.

- A weak cold front is possible next week as a shortwave trough moves over the Southern Plains. This will bring a cooler, wetter pattern to the region more typical of the fall.

- There is a moderate risk of rip currents at area beaches.

DISCUSSION

Issued at 1235 PM CDT Fri Sep 25 2026

Unseasonably warm and humid conditions continue for Deep South Texas. High pressure is still settled over Central-Southeast Texas, supporting an easterly flow to our region on the underside of the center of the high. This will continue supporting low to moderate (20 to 40%) chances for sea breeze showers and thunderstorms this afternoon throughout the area. Conditions are expected to dry up this weekend, as the dome of high pressure strengthens and suppresses convective formation due to strong upper-level subsidence.

Rain chances will return Monday as easterly surface flow continues while the the dome of high pressure breaks down. Upper-level Pacific moisture is expected to approach the area from Southwest Mexico. A shortwave is also expected to simultaneously move over the CONUS from the west and reach the Southern Plains by Friday. Though showers and thunderstorms are expected to be mainly along the sea breeze Monday and Tuesday, this more disturbed pattern later in the week containing both surface Gulf moisture and upper-level Pacific moisture will bring widespread low to moderate rain chances to all of Deep South Texas Wednesday and Thursday.

Temperatures remain above seasonal normals, reaching the upper 90s and lower 100s each day, with lows in the mid to upper 70s. While no Special Weather Statements or Heat Advisories are expected to be issued through the weekend, a Moderate (level 2 of 4) to Major (level 3 of 4) Heat Risk remains in place over the next couple of days. With the increase in overall moisture in the environment, Heat Risk is expected to increase to Major to Extreme (level 4 of 4) by the start of the work week, as "feels like" temperatures go up with with increased humidity.

Longer-range guidance hints at a potential pattern change late next week as the aforementioned trough moves across the Central-Southern Plains. This trough may bring a much-welcome weak cold front to the region by Thursday, and also usher in an overall cooler, rainier pattern that is more typical to Deep South Texas this time of year. High temperatures should fall about five degrees on Friday, and it appears that strong upper-level high pressure (conducive to unseasonably hot, dry weather) is unlikely to reestablish itself immediately after the frontal passage. This is more favorable toward additional shortwave activity in the coming weeks.

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

AVIATION

(00Z TAFS) Issued at 517 PM CDT Fri Sep 25 2026

Through 00z Sunday....VFR conditions are expected to prevail through the 00z TAF cycle under mostly sunny to partly cloudy skies.

East-northeast winds 10-15 kts this evening will trend towards light and variable to calm tonight. An east-northeast component will develop once again on Saturday with wind speeds between 10-15 kts and maybe some occasional gusts up to 20 kts.

MARINE

Issued at 1235 PM CDT Fri Sep 25 2026

Favorable conditions are expected over the next several days with light to moderate easterly winds and low to moderate (2-4 feet) wave heights. SCEC and/or Small Craft Advisory conditions are possible by the middle of next week as a weak cold front is expected to approach the area.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 80 96 79 96 / 10 20 0 10 HARLINGEN 75 99 74 99 / 0 10 0 10 MCALLEN 78 101 78 102 / 10 10 0 10 RIO GRANDE CITY 76 100 77 101 / 10 10 0 0 SOUTH PADRE ISLAND 82 89 82 89 / 0 10 0 10 BAYVIEW/PORT ISABEL 79 94 77 94 / 0 10 0 10

BRO WATCHES/WARNINGS/ADVISORIES

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