textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 614 AM CDT Sat Apr 18 2026

Key Messages:

* A cold front is expected Saturday night into Sunday morning which will bring moderate to high (60-90%) chances for rain through Tuesday morning.

* Most areas should receive between 1 and 2 inches of rain, but some areas could see locally heavier amounts of 3 to 4 inches. Isolated flash flooding is possible in low-lying or poor drainage areas that receive heavier rainfall.

* Temperatures will fall 15-30 degrees into Sunday morning. * A high risk of rip currents is expected over the weekend with elevated surf and minor coastal flooding near high tide cycles.

DISCUSSION

Issued at 1047 PM CDT Fri Apr 17 2026

Above normal temperatures and mainly rain-free conditions are expected tonight into Saturday afternoon. However, isolated showers and thunderstorms may develop across portions of the Rio Grande Plains by late Saturday afternoon as a cold front approaches the region. Lows tonight will fall into the low to mid 70s under mostly cloudy skies. Saturday will be very warm to hot with high tempeatures in the lower 90s, except for the 80s near the coast. Moderate to breezy conditions will continue through Saturday afternoon due to the enhanced pressure gradient.

The cold front is expected to move into the Rio Grande Plains and the northern ranchlands late Saturday night and push through the Rio Grande Valley Sunday morning. There is high (70-90%) chance of showers and a few thunderstorms with the passage of the cold front Saturday night. Widespread and beneficial rain continues on Sunday in the wake of front. Weather Prediction Center maintains a marginal (level 1 of 4) risk of excessive rainfall across most of Deep South Texas for Sunday and Sunday night with a small portion over northeast of the CWA Monday into Monday night. The combination of the lingering frontal boundary and a weak surface low will support moderate to high (50-80%) chance of rain Sunday through Monday night. A low (20-30%) chance of showers and a few thunderstorms will be possible Tuesday through Wednesday. Drier conditions return Wednesday night through the end of the week as a surface/coastal through moves farther to the east.

Most likely rainfall amounts between Saturday evening and Tuesday morning for most areas are expected to be between 1-2 inches, with some areas receiving closer to 3-4 inches in areas of locally heavy rainfall. Any slow moving heavier showers or thunderstorms has a small chance for nuisance and isolated flash flooding in low lying and poor-drainage areas.

In the wake of the front, much more noticeable temperatures will occur on Sunday. Daytime highs on Sunday will be cool, especially across the west and the northern ranchlands, may remain in the mid 60s. In fact, the latest NAM is suggesting that temperatures may remain in the 50s across ranchlands. Will lower temperatures on Sunday a few degrees, closer to the NBM25. Overnight lows Sunday night are expected to range from the upper 50s across the Rio Grande Plains to the mid 60s near the coast. Monday will be mild with highs in the mainly in the 70s. Temperatures will recover to near normal on Tuesday and above by late week as drier conditions continue.

Hazardous coastal conditions are anticipated with the passage of the cold front, including life-threatening rip currents and elevated surf, as well as some potential beach run-up near high tide cycles, as astronomical tides begin to increase over the weekend.

AVIATION

(12Z TAFS) Issued at 614 AM CDT Sat Apr 18 2026

Mostly MVFR conditions, however there could be a few periods of VFR during the early part of the TAF cycle. Around mid-morning, southeasterly winds are expected to become gusty with gusts up to 25 knots possible. Towards the later part of the afternoon and early evening hours, showers and thunderstorms associated with a cold front will move into the region. It is possible that some of these showers and thunderstorms could cause IFR or LIFR conditions due to low ceilings or low visibilities due to heavy downpours.

MARINE

Issued at 1047 PM CDT Fri Apr 17 2026

Moderate winds and seas with Small Craft Exercise Caution conditions prevail along the Lower Texas Coast late this evening due to an enhanced pressure gradient. More favorable conditions with southeast winds of 10 to 15 knots and seas of 3 to 5 feet should develop on Saturday as the pressure gradient weakens ahead of the next front. However, Small Craft Advisory conditions are expected to develop early Sunday morning with the passage of the cold front. More favorable conditions will return late Tuesday before Exercise Caution conditions could then develop again by Friday.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 88 69 74 68 / 0 70 90 70 HARLINGEN 90 64 73 64 / 0 70 80 70 MCALLEN 92 64 70 64 / 10 70 80 70 RIO GRANDE CITY 92 59 65 59 / 20 70 80 60 SOUTH PADRE ISLAND 81 71 73 70 / 0 60 80 70 BAYVIEW/PORT ISABEL 87 68 75 67 / 0 60 80 70

BRO WATCHES/WARNINGS/ADVISORIES

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