textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1208 PM CDT Thu Aug 20 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 1208 PM CDT Thu Aug 20 2026

Upper level ridging will continue to lead to hot temperatures and dry conditions across Deep South Texas through this week into next. 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. 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, can not rule out very isolated sea breeze activity through the remainder of the period, though chances remain less than 5%.

Breezy conditions will continue this week. Winds in combination with lower RH value and abnormally dry conditions could lead to the potential for rapid wildfire spread if ignition occurs. While we shy of and Red Flag Warnings or Fire Danger Statements, outdoor burning is not recommended.

AVIATION

(18Z TAFS) Issued at 1208 PM CDT Thu Aug 20 2026

VFR conditions will prevail at all aerodromes. Gusty southeasterly winds will continue through this evening with gusts to around 25 kts.

MARINE

Issued at 1208 PM CDT Thu Aug 20 2026

An enhanced pressure gradient along the immediate coast each day will result in Small Craft Exercise Caution conditions at times, primarily 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 81 98 80 99 / 0 0 0 0 HARLINGEN 78 103 75 103 / 0 0 0 0 MCALLEN 81 104 79 105 / 0 0 0 0 RIO GRANDE CITY 79 105 77 105 / 0 0 0 0 SOUTH PADRE ISLAND 82 90 81 90 / 0 0 0 0 BAYVIEW/PORT ISABEL 80 97 78 98 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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