textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1226 AM CDT Fri Aug 7 2026

- A Special Weather Statement (SPS) may be issued for the inland portions of Kenedy and Willacy counties on Friday, where heat indices could peak as high as around 108-111 F during the afternoon and early evening hours.

- A low (10-20%) chance of rain along/east of US-281 on Friday and Saturday increases to a low to medium (20-40%) chance on Sunday, likely highest across the Lower RGV.

- Increased cloud cover over the weekend reduces heat risks to minor to moderate (levels 1 and 2 of 4), but decreasing cloud coverage and diminishing rain chances early next week result in major to extreme heat risks (levels 3 and 4 of 4) by the middle of next week.

- SPSs are likely and heat advisories are possible again by next Monday as afternoon heat indices climb back to 108-111+ F, progressively warming further throughout the week.

- A medium risk of life-threatening rip currents continues through tonight, becoming a low risk Friday morning through Friday afternoon.

DISCUSSION

Issued at 1035 PM CDT Thu Aug 6 2026

Mid/upper level shortwaves riding along the ridge of a high pressure aloft, centered over the 4 Corners region, help to increase cloud cover and chances of afternoon and early evening seabreeze boundary showers and thunderstorms over the weekend. Although pulses of Gulf moisture associated with, and behind, the seabreeze could push PWAT values to 2.0+ in. at times, mid-levels may struggle a bit more to moisten, due to influence of nearby high pressures; convection may remain fairly isolated, scattered at best, and brief in nature. Nonetheless, chances of rain increase, generally along and east of US-281, from a low (15-20%) chance on Friday and a low (10-15%) chance on Saturday to a low to medium (20-40%) chance on Sunday. The highest chances are anticipated to be across the Lower RGV, where the influence of troughing aloft and higher moisture content remain the most supportive. Brief periods of isolated heavy rain, frequent lightning and some higher gusts are still possible.

Additionally, increasing cloud cover is expected to cool temperatures by a few degrees throughout the weekend, resulting in inland high temperatures mostly in the mid/upper 90s while lower 100s become limited to the Rio Grande Plains and the Upper RGV. Yet, relatively sunnier skies and humid conditions on Friday may result in a SPS being issued later tonight or Friday morning for inland portions of Kenedy and Willacy counties, where Friday afternoon and early evening heat indices could reach 108-111 F. Otherwise, mostly moderate heat risks on Friday slightly improve to a minor to moderate risk across the Northern Ranchlands on Saturday and Sunday while the RGV and Rio Grande Plains maintain a moderate heat risk.

By Sunday night, another expanding and building area of high pressure aloft over the northeastern Gulf is progged to suppress cloud and convection development, thus leading to drier conditions, with widespread lower/mid 100s and moderate heat risks returning to most inland areas by Monday afternoon, when SPS become likely again for heat indices of 108-111+ F. Heat advisories are possible as well, particularly by the middle to later parts of next week, as a tightening pressure gradient enhances moisture content via stronger southeasterly winds, possibly gusting to 25-35+ mph, causing heat indices to warm further, and heat risks to deteriorate to major, with pockets of extreme heat risks.

A medium risk of life-threatening rip currents continues through tonight, becoming a low risk Friday morning through Friday afternoon.

AVIATION

(06Z TAFS) Issued at 1226 AM CDT Fri Aug 7 2026

Light southeast winds between 6 to 12 kts with a few passing low to mid level clouds prevail across Deep South Texas early this morning. Light winds will continue overnight are expected to increase to 15 to 20 kts by mid to late morning with some gusts around 25 kts in the afternoon. VFR conditions are forecast to continue for the next 24 hours.

MARINE

Issued at 1035 PM CDT Thu Aug 6 2026

Gentle to moderate easterly to southeasterly winds and slight to moderate (1-3 ft) seas become moderate to fresh southeasterly winds, with moderate (3-5 ft) seas and periods of Small Craft Exercise Caution conditions by next Monday as a pressure gradient tightens across the Lower Texas coastal waters. Chances of rain with embedded thunderstorms increase from as much as a low (20%) chance on Friday afternoon to as much as a medium (60%) chance on Saturday and Sunday before diminishing to less than a 10% chance by next Monday.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 96 78 95 79 / 10 0 10 10 HARLINGEN 97 75 96 75 / 10 0 10 10 MCALLEN 101 78 100 79 / 20 0 10 0 RIO GRANDE CITY 101 77 100 77 / 10 0 10 0 SOUTH PADRE ISLAND 88 80 87 80 / 0 0 10 10 BAYVIEW/PORT ISABEL 94 77 92 77 / 10 0 10 10

BRO WATCHES/WARNINGS/ADVISORIES

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