textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1155 AM CDT Sat Aug 15 2026

- Hot, mostly dry, and at times breezy conditions will continue.

- There is a 20-30% chance for an isolated to scattered shower or thunderstorm along the sea breeze on Monday along and east of IH- 69C/US-281; best timing between 11am-5pm CDT.

- Though no headlines are out at this time, fire weather concerns will remain on the table through next week.

- Generally favorable marine conditions are expected through next week with low to moderate winds and seas; Small Craft Exercise Caution (SCEC) conditions are possible over the Laguna Madre during the middle parts of next week.

- There remains a moderate risk for rip currents along the Lower Texas Coast beaches through Sunday.

DISCUSSION

Issued at 1155 AM CDT Sat Aug 15 2026

Hot, mainly rain-free, and at times breezy conditions will prevail through the forecast period or through next week across Deep South Texas and the Rio Grande Valley as a strong 594 dam sub-tropical heat dome remains anchored overhead.

High temperatures during this time will range from the upper 90s to the mid 100s. Combine that with dewpoint temperatures in the 70s and heat indices will generally range between 105-115F degrees each day through next week. This will continue to result in Moderate (Level 2 of 4) to Major (Level 3 of 4) Heat Risk with pockets of Extreme (Level 4 of 4) Heat Risk through next week. Additional Special Weather Statements (SPSs) will be needed in the coming days across at least parts of the region with areas closer to the coast most favored due to higher humidity levels.

A few hi-res and AI/ML models have been signaling for the possibility of showers and thunderstorms developing along a sea breeze on Monday. Currently, we have low (20-30%) chances for such an event with the greatest confidence being aligned along and east of the IH-69C/US-281 corridor. The best timing for any showers or thunderstorms will be between the hours of 11am-5pm CDT.

The persistently hot and dry antecedent pattern with high evaporation rates and at times breezy conditions will aid in increased fire weather concerns through next week, particularly in the Tuesday through Friday time period as minimum relative humidity values get to near Fire Danger Statement (RFD) criteria. Even though, we do not have any fire weather headlines at this time, we urge that you continue to exercise fire weather safety measures.

AVIATION

(18Z TAFS) Issued at 1155 AM CDT Sat Aug 15 2026

Through 18z Sunday....VFR conditions, by and large, will prevail through the 18z TAF cycle. There could be a few MVFR clouds around from time to time, especially during the overnight hours into early Sunday morning.

Southeast winds 10-15 kts with gusts as high as 25 kts will continue through this afternoon/evening before waning later this evening/tonight. Tonight, winds will trend towards light and variable if not a slight component out of the southeast with wind speeds up to 5 kts. Winds will pick up in magnitude once again on Sunday as mixing heights increase.

MARINE

Issued at 1155 AM CDT Sat Aug 15 2026

Generally favorable marine conditions are expected along the Lower Texas Coast through the next several days, with light to moderate winds and low to moderate seas in place. However, winds may increase over the Laguna Madre during the middle part of next week, which could require Small Craft Should Exercise Caution at times.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 80 96 80 97 / 10 10 10 20 HARLINGEN 77 98 76 99 / 0 10 10 20 MCALLEN 81 102 80 102 / 0 10 0 10 RIO GRANDE CITY 78 102 78 102 / 0 0 0 10 SOUTH PADRE ISLAND 81 89 81 89 / 10 10 10 10 BAYVIEW/PORT ISABEL 79 94 78 95 / 0 10 10 10

BRO WATCHES/WARNINGS/ADVISORIES

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