textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 539 PM CDT Wed Sep 9 2026

- A Special Weather Statement has been issued for all of Deep South Texas for high heat indices between 108-111 degrees today.

- Record breaking temperatures and Major (level 3 of 4) to Extreme (level 4 of 4) Heat Risk is expected throughout much of Deep South Texas through the middle of next week.

- There is a low to moderate (20-40%) chance of sea breeze showers and thunderstorms E of I-69C today and tomorrow before conditions dry out for Friday and the early weekend.

DISCUSSION

Issued at 1215 PM CDT Wed Sep 9 2026

Strong upper-level ridging continues over the Southern Plains through at least the middle of next week, which will keep conditions unseasonably hot and mostly rain-free throughout Deep South Texas. Record-breaking temperatures and 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 has been issued for all of Deep South Texas today for heat indices that could reach between 108-111 degrees, and possibly even briefly exceed 111 degrees this afternoon into early evening. Additional Heat Advisories and/or Special Weather Statements may be needed later this week as well as record heat continues.

The best chances (30-40%) of sea breeze convection will occur this afternoon, as the moisture profile is expected to be the highest of any day this week. Chances will linger tomorrow as well, but stay a little lower (around 20%) before conditions dry up for the weekend. Chances resume again by the middle of next week as another pulse of Gulf moisture moves over the area. Most sea breeze activity each day will be concentrated east of I-69C.

AVIATION

(00Z TAFS) Issued at 539 PM CDT Wed Sep 9 2026

Through 00z Friday....By and large, VFR conditions will prevail through the 00z TAF cycle. There is a low, non-zero probability for an isolated shower or thunderstorm along the sea breeze Thursday afternoon. However, given the low coverage and chance for showers or thunderstorms, have not included in the TAFs at this time.

Southeast winds 10-15 kts this evening will trend towards light and variable to calm tonight. Southeasterly winds will develop once again on Thursday with speeds between 10-15 kts.

MARINE

Issued at 1215 PM CDT Wed Sep 9 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 starting Friday due to a slightly tightening pressure gradient, and SCEC conditions may become possible on the Laguna Madre in the afternoons through the middle of next week. Wave heights may slightly increase as well.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 80 98 81 98 / 0 10 0 0 HARLINGEN 76 101 77 102 / 0 20 10 0 MCALLEN 80 104 81 104 / 10 10 10 0 RIO GRANDE CITY 79 104 80 105 / 10 0 10 0 SOUTH PADRE ISLAND 82 90 83 91 / 0 10 0 0 BAYVIEW/PORT ISABEL 78 95 79 97 / 0 20 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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