textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 642 AM CDT Sun Aug 23 2026

- Hot and rain-free conditions will continue through late 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 1047 PM CDT Sat Aug 22 2026

A strong 500 mb ridge will meander over southern New Mexico/western Texas and northern Mexico extending over Texas through late next week. This will continue to provide subsidence across Deep South Texas with very hot and mainly 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 the weekend and into the middle of next week.

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

(12Z TAFS) Issued at 642 AM CDT Sun Aug 23 2026

VFR conditions are forecast to continue through the TAF period. southeasterly winds are forecast to shift more easterly and increase to around 10 knots this afternoon. Winds will likely briefly gusts to around 20 knots as the sea breeze moves through early this afternoon, with gusts diminishing by late afternoon. Light and variable winds are forecast to develop overnight.

MARINE

Issued at 1047 PM CDT Sat Aug 22 2026

Favorable marine conditions will prevail along the lower Texas Coast through the period as high pressure continues across the Gulf. Light to occasionally moderate south to southeast winds and low seas are expected through late next week.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 99 80 98 79 / 0 0 0 0 HARLINGEN 102 76 102 75 / 0 0 10 0 MCALLEN 105 79 104 79 / 0 0 0 0 RIO GRANDE CITY 105 76 104 76 / 0 0 0 0 SOUTH PADRE ISLAND 89 81 89 81 / 0 0 0 0 BAYVIEW/PORT ISABEL 97 78 96 78 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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