textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 636 AM CDT Tue Aug 18 2026

- Hot, dry, and at times breezy conditions will continue through the week and into the weekend.

- Moderate (level 2 of 4) to major risk (3 of 4) of heat-related impacts through the weekend with peak afternoon heat indices generally between 105 to around 110 degrees.

- There is a potential of elevated fire weather conditions across the Rio Grande Plains and portions of the northern ranchlands.

DISCUSSION

Issued at 1034 PM CDT Mon Aug 17 2026

A mid-level ridge over the Four Corners extending over Texas will provide subsidence across the region through late week and into the weekend. Therefore, hot and rain-free conditions are forecast to continue through period. Daily high temperatures are expected to range from the the upper 90s to around 105 degrees, except near the coast. The combination of hot temperatures and elevated dewpoints in the 70s 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, especially Thursday and Friday. Widespread Moderate (Level 2 of 4) to Major (Level 3 of 4) Heat Risk expected through late week into the weekend. Special Weather Statements (SPS) and maybe a Heat Advisory will be needed later this week for portions of the area, especially near the coast.

The hot, dry, and at times breezy conditions will support the potential increase of fire weather concerns through the weekend. Minimum relative humidity below 30 percent is expected each afternoon, mainly along and west of I-69C/US 281.

AVIATION

(12Z TAFS) Issued at 636 AM CDT Tue Aug 18 2026

VFR will prevail at the aerodromes through the next 24 hours. Breezy winds with higher gusts on Tuesday will be bookended by lighter winds for the nighttime hours. Dry weather with limited cloud cover is also anticipated.

MARINE

Issued at 1034 PM CDT Mon Aug 17 2026

Generally favorable marine conditions will prevail along the Lower Texas Coast through the period with light to moderate winds and low to moderate seas. However, winds may increase over the Laguna Madre mid to late week, which could require Small Craft Should Exercise Caution at times.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 97 80 97 82 / 0 0 0 0 HARLINGEN 101 76 101 79 / 0 0 0 0 MCALLEN 103 79 103 81 / 0 0 0 0 RIO GRANDE CITY 103 77 103 79 / 0 0 0 0 SOUTH PADRE ISLAND 90 81 90 82 / 0 0 0 0 BAYVIEW/PORT ISABEL 96 79 97 80 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

None.