textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1035 PM CDT Wed Aug 19 2026

- Hot and rain-free conditions will continue through early next week. - Moderate (level 2 of 4) to major risk (3 of 4) of heat-related impacts through the period with peak afternoon heat indices generally between 105 to around 110 degrees.

- The combination of low minimum relativity humidity values, dry fuels, and very hot temperatures could lead to the potential for rapid wildfire spread through the period.

DISCUSSION

Issued at 1035 PM CDT Wed Aug 19 2026

A mid-level ridge anchored over the Four Corners region Friday will gradually move southeastward over Texas this weekend into early next week. This will continue to lead to strong subsidence across Deep South Texas with very hot and rain-free conditions through forecast period. Daily high temperatures are expected to reach the upper 90s to around 105 degrees, except near the coast. The combination of the very hot temperatures and elevated dewpoint temperatures will support heat indices generally between 105 to 110 degrees each afternoon. Heat indices may briefly reach 111+ at a few locations in the afternoon, but temperatures should remain just below Heat Advisory criteria each day. Widespread Moderate (Level 2 of 4) to Major (Level 3 of 4) Heat Risk expected through late week into the weekend.

The combination of low minimum relativity humidity values, dry fuels, and very hot temperatures could lead to the potential for rapid wildfire spread through the period.

AVIATION

(00Z TAFS) Issued at 638 PM CDT Wed Aug 19 2026

Southeast winds 15 to 20 kts with gusts around 25 kts prevail across Deep South Texas early this evening. Winds are expected to gradually decrease later this evening and overnight. Southeast winds will increase and become moderate and gusty mid to late morning. Some gusts around 25 knots will be possible in the afternoon. VFR conditions are expected for the next 24 hours.

MARINE

Issued at 1035 PM CDT Wed Aug 19 2026

A slightly enhanced pressure gradient over the western Gulf may produce brief Small Craft Should Exercise Caution conditions on the Laguna Madre at times Friday through the weekend. Otherwise, mariners can expect moderate south to southeast winds and seas of 2 to 3 feet through the period.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 97 82 97 81 / 0 0 0 0 HARLINGEN 101 79 101 78 / 0 0 0 0 MCALLEN 103 81 103 81 / 0 0 0 0 RIO GRANDE CITY 103 79 104 79 / 0 0 0 0 SOUTH PADRE ISLAND 90 82 90 82 / 0 0 0 0 BAYVIEW/PORT ISABEL 97 80 97 80 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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