textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1207 PM CDT Mon Sep 7 2026

- High Heat Indices (between 108 to 111) are expected for all of Deep South Texas (excepting the islands) this afternoon.

- Major (level 3 of 4) to Extreme (level 4 of 4) Heat Risk will continue through early next week.

- There is a low (10-30%) chance of sea breeze showers and thunderstorms E of I-69C each afternoon this week through Wednesday.

DISCUSSION

Issued at 1207 PM CDT Mon Sep 7 2026

Upper-level ridging will continue throughout the Southern Plains through early next week, which will continue keeping conditions unseasonably hot and mostly rain-free throughout Deep South Texas. Major (level 3 of 4) to Extreme (level 4 of 4) Heat Risk is expected to persist through the weekend into next week. A Special Weather Statement is in effect this afternoon for anticipated heat indices between 108-111 degrees for all of Deep South Texas, excepting the islands. More Special Weather Statements and possibly Heat Advisories are possible this week as temperatures and heat indices remain high.

An influx of surface Gulf moisture will fuel low (10-30%) daily chances for sea breeze convection each afternoon, primarily for areas east of I-69C. These chances are expected to continue through Wednesday, and then conditions should briefly dry up through the first half of the weekend. Low chances for sea breeze convection resume again on Sunday and continue into early next week.

AVIATION

(18Z TAFS) Issued at 1207 PM CDT Mon Sep 7 2026

VFR conditions with few clouds are expected at all airports. Light to moderate southeasterly winds are expected with the potential for a few gusts.

MARINE

Issued at 1207 PM CDT Mon Sep 7 2026

Favorable conditions are expected over the next several days with light to moderate southeasterly winds and low (1-3 feet) wave heights. Winds are expected to increase this weekend due to a slightly tightening pressure gradient, and SCEC conditions may become possible on the Laguna Madre in the afternoons.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 81 98 80 97 / 10 10 0 40 HARLINGEN 77 101 77 100 / 0 20 0 40 MCALLEN 81 103 81 102 / 0 20 0 20 RIO GRANDE CITY 79 103 79 103 / 0 10 0 10 SOUTH PADRE ISLAND 82 90 82 89 / 10 10 10 30 BAYVIEW/PORT ISABEL 79 96 79 95 / 10 10 0 40

BRO WATCHES/WARNINGS/ADVISORIES

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