textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 618 AM CDT Fri Jun 5 2026

* Day-to-day or near day-to-day shower and thunderstorm chances are expected to continue through next Monday; mainly dry (drier trends) Tuesday through Friday of next week.

* There's low-medium (20-50%) chances for showers and thunderstorms through next Monday. Friday into Friday evening, there remains a medium (30-60%) chance for showers and thunderstorms.

* Brief periods of heavy rainfall, frequent lightning, small hail, and gusty winds will be the main threats in the stronger storms.

* Seasonable temperatures on persistent east-southeast winds will prevail through next week; heat risk could begin increasing becoming more widespread next week.

* Widespread Moderate (Level 2 of 5) Heat Risk is expected to develop beginning Sunday and persisting through the next week; peak heat indices will range between 100-110F degrees.

DISCUSSION

Issued at 1029 PM CDT Thu Jun 4 2026

Daily chances for showers and thunderstorms on persistent east- southeast winds with near seasonable temperatures will continue to be the main weather storyline through early next week. Early indications continue to suggest that next week will be drier than this week overall as rain probabilities and coverage will be lower next week compared to this week, courtesy of a re-strengthening mid- upper level heat ridge.

Forecast models continue to depict the sfc and upper level high pressure systems in a weakened state through the weekend. High atmospheric moisture content with PWAT values ranging between 1.8- 2.5", some 2-3 STDEVs above normal, elevated instability values, some synoptic forcing, and increased sfc convergence from a sea breeze will continue to support day-to-day or near day-to-day chances for showers and thunderstorms through Monday. Coverage generally will be isolated to scattered each day with the best chances and coverage for showers and thunderstorms being Friday- Friday evening.

In general, through next Monday, there remains a low-medium (20-50%) chance for showers and thunderstorms. Friday will present the greatest rain and thunderstorm chances due to a combination of sea breeze interaction and synoptic influences. That's where we have medium (30-60%) chances for showers and thunderstorms (highest favoring areas west of IH-69C/US-281). Brief periods of heavy rain, frequent lightning, and maybe some small hail and gusty winds will be the main threats with the stronger storms.

Given the high PWAT values, locally heavy rainfall could lead to localized nuisance ponding or flooding, particularly in your typical low-lying, urban, poor drainage areas.

Day-to-day or near day-to-day rain chances could continue through the early parts of next week. However, confidence and coverage remains low at this time as a 588-591 dam heat dome strengthens overhead. That said, mainly dry weather conditions can be expected, however, a rogue shower or thunderstorm is possible Sunday through Wednesday of next week. Rain probabilities at this point remains maxed out at 20% each of those days.

Clouds and maybe an isolated shower or thunderstorm will help to keep the heat in check through next week. Overall, temperatures are expected to run normal to warmer than normal levels for the period High temperatures are expected to run between the lower 90s near the coast to the mid to upper 90s west. Meanwhile, overnight lows are expected to be mainly in the 70s (80s across much of Cameron County) through next week.

Heat Risk is expected to become more widespread Sunday through next week in conjunction with the drier trends. Currently, we have Moderate (Level 2 of 5) Heat Risk developing over much, if not all, of Deep South Texas on Sunday and persisting through next Friday. Heat indices are progged to range between 100-110F degrees late weekend through late next week.

AVIATION

(12Z TAFS) Issued at 618 AM CDT Fri Jun 5 2026

VFR conditions are expected to generally prevail through the TAF period with the chance of showers and thunderstorms, mainly this afternoon. Brief heavy rainfall and occasional cloud to ground lightning can be expected near any thunderstorm activity.

MARINE

Issued at 1029 PM CDT Thu Jun 4 2026

Outside of the daily or near daily threat for showers and t'storms through Monday of next week, favorable marine conditions with light to moderate winds and seas are expected to persist through much of the forecast period. The only exception will be Sunday through Monday of next week as slightly stronger winds could result in adverse marine conditions such as Small Craft Exercise Caution (SCEC) conditions.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 91 80 90 81 / 30 20 20 20 HARLINGEN 91 76 90 77 / 30 20 20 10 MCALLEN 92 78 92 79 / 40 30 10 10 RIO GRANDE CITY 90 75 93 77 / 50 50 0 0 SOUTH PADRE ISLAND 86 82 86 83 / 10 20 30 20 BAYVIEW/PORT ISABEL 89 79 89 80 / 20 20 20 10

BRO WATCHES/WARNINGS/ADVISORIES

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