textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1209 PM CDT Fri Aug 21 2026

- Hot and dry conditions will continue through the forecast period.

- 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.

- The combination of breezy and mostly dry weather coinciding with low afternoon minimum relative humidity values brings a continued risk of fire weather into next week.

DISCUSSION

Issued at 1209 PM CDT Fri Aug 21 2026

No changes to the going forecast. Upper level ridging continues to lead to hot temperatures and dry conditions across Deep South Texas. Temperatures each day will rise into the upper 90s (closer to the coast) to low 100s with heat indices between 105-110F expected. We continue to remain just shy of Heat Advisory criteria each day but a few locations may briefly exceed 111F. Will continue to monitor for the need of Heat Advisories, though at this time Special Weather Statements should suffice. There is a Moderate (level 2 of 4) to Major (level 3 of 4) Heat Risk every afternoon into next week.

While dry conditions will prevail (less than 5%), can not rule out very isolated sea breeze activity through the remainder of the period.

Breezy conditions in combination of lower RH value and abnormally dry conditions could lead to the potential for rapid wildfire spread if ignited. While we will look to fall shy of and Red Flag Warnings or Fire Danger Statements, outdoor burning is not recommended.

AVIATION

(18Z TAFS) Issued at 1209 PM CDT Fri Aug 21 2026

VFR conditions will prevail through the TAF period. Moderate southeasterly winds will continue and gust up to around 20 kts.

MARINE

Issued at 1209 PM CDT Fri Aug 21 2026

While generally favorable conditions will prevail, an enhanced pressure gradient along the immediate coast may result in brief Small Craft Exercise Caution conditions at times across the Laguna Madre. Otherwise, expect light to moderate southeasterly winds with 2 to 3 ft seas and 4 to 6 second periods.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 98 80 99 79 / 0 0 0 0 HARLINGEN 102 76 104 75 / 0 0 0 0 MCALLEN 104 79 105 78 / 0 0 0 0 RIO GRANDE CITY 105 77 105 76 / 0 0 0 0 SOUTH PADRE ISLAND 90 81 90 80 / 0 0 0 0 BAYVIEW/PORT ISABEL 97 78 98 78 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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