textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1236 AM CDT Tue Mar 31 2026

Key Messages:

* Unseasonably warm, dry, and breezy to windy conditions this week improve behind a cold front with deep moisture this weekend.

* Showers and thunderstorms are expected Saturday into Monday, with early total rainfall estimates of 1-2 inches by Monday morning.

* Breezy to windy conditions this week and a cold front this weekend will create adverse marine conditions across the bay and Gulf waters.

DISCUSSION

Issued at 1022 PM CDT Mon Mar 30 2026

A much welcomed pattern change is finally arriving with the start of April. Above normal temperatures and very breezy afternoons continue through the remainder of the week before a cold front arrives Saturday night into Sunday, offering up a 10-15 degree cooler swing from late Easter weekend into early next week.

More importantly, aside from the break in the heat, rainfall is looking more and more likely by the holiday weekend. The chance for sea breeze convection returns mid to late week with low POPs (10-20 percent), but at least some sign of life on radar and hopefully in some rain gauges. A much better chance of rain is taking place ahead of, with, and behind the frontal passage Saturday into Monday with a weak coastal trough and surface low hanging around, extending both instability and deeper moisture. PWAT values near 1.8 to 1.9 inches arrive Saturday night into Sunday, well above the 90th percentile for early April. In fact, extreme forecast indices highlight the CWA for potentially excessive rainfall Saturday night into Sunday night. There is currently a 20 to 30 percent probability of rainfall above 1 inch from Saturday afternoon through Sunday afternoon across most of the region, with close to 50 percent probability from southern Zapata to southern Starr counties. Any thunderstorm in this atmosphere will be an efficient rainmaker and given the lack of rainfall for well over a month to month and a half for some locations, runoff and flash flood concerns may be warranted.

Long droughts in Texas upended by flooding rain is very well documented, so this will continue to be monitored through the week. There is plenty of time to clean and prepare drainage ditches or canals and get any rain catching buckets or barrels into place. The best chance of any severe weather will be Saturday afternoon into early Sunday morning. Stay tuned!

AVIATION

(06Z TAFS) Issued at 1236 AM CDT Tue Mar 31 2026

Light to moderate southeast winds and mostly clear skies prevail across Deep South Texas early this morning. Light southeast winds overnight will increase and become breezy by mid-morning. Some gusts around 25 knots or slightly higher will be possible in the afternoon. VFR conditions are expected for the next 24 hours.

MARINE

Issued at 1022 PM CDT Mon Mar 30 2026

Southeasterly winds persist into the weekend with an enhanced pressure gradient along the lower Texas coast increasing winds each afternoon to SCEC and borderline SCA conditions. A cold front late Saturday into Sunday brings northerly winds and potential SCA conditions across the Gulf, as well as showers and thunderstorms Saturday night into early Sunday.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 86 71 87 72 / 30 10 20 10 HARLINGEN 89 68 92 69 / 20 0 10 0 MCALLEN 93 72 95 74 / 20 10 10 10 RIO GRANDE CITY 94 70 97 70 / 10 10 0 10 SOUTH PADRE ISLAND 79 73 79 73 / 30 10 20 10 BAYVIEW/PORT ISABEL 85 69 86 70 / 30 10 10 10

BRO WATCHES/WARNINGS/ADVISORIES

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