textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1215 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

(18Z TAFS) Issued at 1215 PM CDT Wed Sep 9 2026

VFR conditions are expected at all airports with southeasterly winds that should be light to moderate, with a gust or two possible this afternoon. There is also the chance for sea breeze convection this afternoon, but confidence was not high enough in any particular location to include a TEMPO in the TAF product. If any showers or thunderstorms do occur, visibility and ceilings could be temporarily reduced.

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 75 101 77 102 / 0 20 10 0 MCALLEN 80 103 81 104 / 10 10 10 0 RIO GRANDE CITY 78 104 79 105 / 10 0 10 0 SOUTH PADRE ISLAND 82 90 82 90 / 0 10 0 0 BAYVIEW/PORT ISABEL 78 96 79 97 / 0 20 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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