textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 549 PM CDT Tue May 19 2026

Key Messages:

* Strong to severe thunderstorms will be possible across ALL of Deep South Texas late tonight into Wednesday morning.

* Daily rain/thunderstorm chances continue into next week.

* Hot and humid conditions will continue this week with a Moderate to Major Heat Risk today and tomorrow.

* A High Risk for Rip Currents is also in effect through this evening.

DISCUSSION

Issued at 107 PM CDT Tue May 19 2026

This week into next will feature multiple chances for showers and thunderstorms. Southwesterly flow aloft will persist into early next week, with multiple perturbations tracking over the region. At the surface, ample moisture will be in place and pool ahead of a stalled frontal boundary in central Texas. Combined, this will lead to daily chances of showers and thunderstorms. PWATs will remain extremely high across the area at 1.75-2.5 inches through the week, which is well above normal, so any convection that does develop could produce heavy rainfall and localized flooding.

Tonight, there is a conditional threat for severe weather across Deep South Texas and the Storm Prediction Center has placed ALL of Deep South Texas in a Marginal Risk (level of 1 of 5) of severe thunderstorms through tonight. A complex of thunderstorms will develop north of the region and move south/southeast late tonight into Wednesday morning. If this line holds together through Deep South Texas and is severe, the main threats will be damaging winds in excess of 58 mph and large hail. Brief heavy rain will also be possible with this activity and could lead to localized ponding of water. The Storm Prediction Center keeps Deep South Texas in a general risk of thunderstorms Wednesday and Thursday, though we can not rule out the potential for additional severe weather through the week.

The Weather Prediction Center has placed Zapata, Jim Hogg, western Starr and northwestern Brooks counties in a Marginal Risk (level 1 out of 4) of excessive rainfall on Wednesday, and all of Deep South Texas in a Marginal Risk of excessive rainfall on Thursday though Saturday. Now through Sunday morning we are currently expecting generally 1 to 2 inches across the region with localized areas of 3 to 4 inches. Areas that see multiple rounds of heavy thunderstorms could potentially see higher totals through the weekend.

Outside of thunderstorm/rain chances, heat will be an additional weather headline through the week. Highs will be in the low to mid 90s through Saturday. There is a a Moderate to Major Heat Risk today an tomorrow with a Minor to Moderate heat risk Thursday through next Tuesday.

At area beaches, there is a high risk of rip currents through this evening.

AVIATION

(00Z TAFS) Issued at 549 PM CDT Tue May 19 2026

Through 00z Thursday....VFR-MVFR conditions will prevail through the 00z TAF cycle. VFR conditions will be more prevalent during the afternoon-evening hours with MVFR conditions more prevalent during the night-morning hours.

Showers and thunderstorms are possible tonight in association with a squall line that will be approaching from central Texas. Currently, there is still quite a bit of uncertainty in whether or not those storms make it into the Rio Grande Valley. That said, at this time, have not included shower or thunderstorm headlines in the TAFs.

Southeast winds will continue through the forecast period with speeds between 8-13 knots and gusts as high as 20-25 knots.

MARINE

Issued at 107 PM CDT Tue May 19 2026

Slightly adverse marine conditions continue on the Laguna Madre and Gulf Waters through tonight becoming more favorable through the rest of the forecast period. Ongoing shower and thunderstorms chances through the weekend may lead to localized higher winds and seas.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 80 92 80 91 / 10 10 10 30 HARLINGEN 78 92 76 91 / 20 10 10 50 MCALLEN 79 94 78 92 / 30 20 20 50 RIO GRANDE CITY 77 94 75 91 / 40 40 40 50 SOUTH PADRE ISLAND 81 85 81 85 / 20 10 10 30 BAYVIEW/PORT ISABEL 80 90 79 89 / 20 10 10 40

BRO WATCHES/WARNINGS/ADVISORIES

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