textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1229 AM CDT Thu Sep 10 2026

- Hot, mainly dry, and at times breezy conditions will continue through the middle parts of next week.

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

DISCUSSION

Issued at 1012 PM CDT Wed Sep 9 2026

Hot, mainly dry, and at times breezy conditions will continue to be the main weather storyline through the middle parts of next week as an anomalously strong and elongated 591-594 dam heat ridge complex remains anchored over the southern U.S. This persistent and dominant feature in our pattern will continue to foster record to near record- breaking heat in the days ahead (see CLIMATE SECTION for more details). High temperatures are progged to continue to climb into the upper 90s to mid 100s through the forecast period with overnight lows in the 70s to lower 80s. Peak heat indices ranging between 105- 115F degrees will continue to warrant day-to-day or near daily Special Weather Statements (SPSs) and/or Heat Advisories through this week. The combination of very hot temperatures during the day and very warm temperatures at night providing little relief, widespread Major (Level 3 of 4) Heat Risk to increasing areas of Extreme (Level 4 of 4) Heat Risk will be the case through the middle parts of next week.

Medium range forecast models are signaling at the Wednesday-Thursday timeframe of next week for our next best and more widespread chances for some much needed rainfall in the form of showers and thunderstorms.

AVIATION

(06Z TAFS) Issued at 1229 AM CDT Thu Sep 10 2026

VFR conditions are forecast to continue through the period. Light and variable winds are forecast overnight, increasing out of the southeast Thursday afternoon.

MARINE

Issued at 1012 PM CDT Wed Sep 9 2026

Marine conditions will remain favorable through this week with low to moderate winds and low seas (i.e. wave heights between 1-3 feet). Moderate seas are expected to develop over the weekend through the middle parts of next week. Shower and thunderstorm chances are also possible during the middle parts of next week.

CLIMATE

Issued at 1012 PM CDT Wed Sep 9 2026

Record to near record-breaking temperatures are possible through at least Saturday, courtesy of a persistent and strong 591-594 dam heat ridge complex established over the southern U.S. Below is a list of the record highs from Thursday September 10th to Saturday September 12th.

Thursday September 10, 2026:

Brownsville: 102F in 2023 Harlingen: 102F in 2023 McAllen: 105F in 2023

Friday September 11, 2026:

Brownsville: 100F in 1900 & 1893 Harlingen: 103F in 1937 McAllen: 103F in 2023

Saturday September 12, 2026:

Brownsville: 100F in 1919 Harlingen: 101F in 2011 & 1930 McAllen: 103F in 1987

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 98 81 98 82 / 10 0 0 0 HARLINGEN 101 77 101 78 / 20 10 0 0 MCALLEN 104 81 104 82 / 10 10 0 0 RIO GRANDE CITY 104 79 105 80 / 0 0 0 0 SOUTH PADRE ISLAND 90 83 90 83 / 10 0 0 0 BAYVIEW/PORT ISABEL 96 79 97 80 / 10 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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