textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 613 AM CDT Fri May 15 2026

Key Messages:

* A Small Craft Advisory on the Laguna Madre goes into effect Friday 1 PM until 1 AM Saturday. Small Craft Exercise Caution headlines are likely to continue into early next week across the Lower Texas coastal waters.

* A Minor to Moderate Heat Risk (Levels 1 and 2 of 4) this weekend become a mostly Major Heat Risk (Level 3 of 4) this Sunday into next Tuesday.

* Heat Risks de-escalate throughout the remainder of next week as unsettled weather gradually increases chances of rain to as much as a low to medium (30-60%) chance.

* There is a Moderate Risk of rip currents through Saturday.

DISCUSSION

Issued at 1037 PM CDT Thu May 14 2026

A series of shortwave troughs aloft moving over the Plains and troughing building over the West Coast slowly push a mid/upper level high pressure eastward across Mexico and to the Gulf into this weekend. Associated areas of surface low pressure over the Southern Plains and the Sierra Madre result in increasingly breezier southeast winds during this timeframe, gusting to 20-30+ mph in the afternoons, thus building moisture content. Dewpoints rise into the mid/upper 70s and PWAT values could surpass 2.0 in. over the weekend and next week, which is above the 90th percentile of sounding climatology for mid/late May. The combined effects of these factors yield a mainly dry, breezy and unseasonably warm forecast into early next week along with increasing concerns for heat-related illnesses. Although high temperatures remain near to slightly above normal, afternoon heat indices of 95-100 F are likely to climb to 105-110 F later in the weekend, even warming by a few degrees into next Tuesday. At this time, we anticipate Minor Heat Risks to elevate to a Moderate Heat Risk on Saturday then further deteriorate to a Major Heat Risk for most of the region by next Monday and Tuesday. SPSs and/or Heat Advisories are possible. Overnight lows gradually increase from the 70s tonight and Friday night to the 70s/80s by possibly Sunday night.

A more robust trough and trailing shortwaves arrive over the Plains early next week. Resulting rounds of Sierra Madre convection could lead to a low to medium (20-40%) chance of rain along/west of US-281 each night, beginning possibly Sunday or Monday night. As the trough moves closer and forcing and divergence aloft become more enhanced and widespread, chances of rain could expand and increase across the region to as much as a low to medium (40-60%) chance by the middle or later part of next week. Increased cloud cover is anticipated help to cool temperatures and heat indices as well as improve heat risks as the week progresses.

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

AVIATION

(12Z TAFS) Issued at 613 AM CDT Fri May 15 2026

VFR conditions prevail. Hot, gusty conditions expected Friday. Southeasterly winds increase over the morning, becoming gusty to around 30 kts through the afternoon and evening.

MARINE

Issued at 1037 PM CDT Thu May 14 2026

Small Craft Exercise Caution headlines are likely to continue into early next week as a tightened pressure gradient maintains mostly moderate to fresh, strong at times, southeasterly winds and moderate (3-6 ft, occasionally higher) seas. Chances of showers and thunderstorms gradually increase throughout next week to as much as a low to medium (30-60%) chance. Meanwhile, winds and seas improve as the pressure gradient loosens.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 90 76 91 80 / 0 0 0 0 HARLINGEN 92 72 92 77 / 0 0 0 0 MCALLEN 94 75 95 79 / 0 0 0 0 RIO GRANDE CITY 97 73 96 77 / 0 0 0 0 SOUTH PADRE ISLAND 83 78 84 80 / 0 0 10 0 BAYVIEW/PORT ISABEL 89 75 89 79 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

TX...None. GM...Small Craft Advisory from 1 PM this afternoon to 1 AM CDT Saturday for GMZ130-132-135.