textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1148 AM CST Fri Nov 28 2025

* Unseasonably warm and dry weather is expected for Saturday.

* A strong cold front is expected to reach our area Saturday night into Sunday which will decrease temperatures to below seasonal normals and increase precipitation chances for our area through Monday.

* Dangerous surf and boating conditions are expected persist through at least Sunday and possibly longer in response to an enhanced pressure gradient and a strong cold front.

DISCUSSION

Issued at 1148 AM CST Fri Nov 28 2025

Surface high pressure is expected to remain over Deep South Texas through tomorrow evening, resulting in unseasonably warm temperatures reaching the low to mid 80s tomorrow afternoon. This surface high will be pushed off to the east by an approaching shortwave coming off the Colorado Rockies, which is expected to usher in a pattern change and a strong cold front to our area tomorrow night into Sunday morning.

This cold front is expected to bring much cooler temperatures to our region, though model guidance is not currently agreeing as to how much colder the temperatures will get. The NAM (which tends to handle stronger cold fronts more accurately in Deep South Texas) is more robust than the Euro/GFS, proposing a temperature drop of around 10 degrees colder than what the Euro/GFS is proposing. For this reason, a little more weight was given to the NAM in blending it with NBM guidance for forecasting the temperatures Sunday through Tuesday.

Present thinking is that low temperatures are expected to get down into the upper 50s/lower 60s Sunday night as the cold front comes through. Low temperatures will then drop into the upper 40s/lower 50s Monday night through Wednesday night before a warming trend begins on Thursday. On Sunday, skies will be cloudy and temperatures should stay in the upper 50s for the Northern Ranchlands and low to mid 60s for the Rio Grande Valley. High temperatures will be coolest on Monday, getting into the upper 50s for most of Deep South Texas and skies remaining cloudy. Gradual clearing should allow Tuesday's highs to warm into the 60s, and Wednesday's highs will continue warming into the 70s, with temperatures staying close to seasonal levels in the 70s through the end of the workweek.

The frontal passage will also bring an increased chance of rain to the area. Chances should start increasing tomorrow night, with a low to medium (20-40%) chance for areas east of I-69C. This will become more widespread on Sunday, with the low to medium (20-40%) chance expanding west of I-69C, and chances increasing to moderate to high (50-70%) for the eastern counties closer to the coast. The best chance for rain in the Western counties will be Sunday night into Monday, when PoPs increase to moderate (around 50%) for most of Deep South Texas (with higher chances holding steady closer to the coast).

Conditions will begin to dry out Monday, with low to moderate (20- 40%) precip chances continuing for areas east of I-69C. The driest days next week will be Tuesday and Wednesday, before chances increase again to low to moderate (20-40%) for all of Deep South Texas on Thursday and low (around 20%) for coastal counties on Friday. There could be some thunderstorms ahead of the front, but precip is expected to transition to stratiform rain and drizzle following the frontal passage.

A high risk of life-threatening rip currents is in effect for area beaches tonight and tomorrow.

AVIATION

(18Z TAFS) Issued at 1148 AM CST Fri Nov 28 2025

VFR conditions are expected at all airports with overcast skies and southeasterly winds that could become gusty at times.

MARINE

Issued at 1148 AM CST Fri Nov 28 2025

Marine conditions are expected to be hazardous to smaller vessels over the next few days as a strong cold front passes through the area. A Small Craft Advisory is currently in effect for the Bay and Gulf waters through tomorrow evening. This may need to be extended depending on the strength of the pressure gradient ahead of the front, and the strength of the winds behind the front. If winds do drop below Small Craft Advisory criteria at any point between now and Tuesday, winds will still be high enough for Small Craft Exercise Caution conditions.

Conditions should start improving on Tuesday night and remain more favorable with light to moderate winds and seas through Friday.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 78 70 83 71 / 30 10 10 30 HARLINGEN 78 66 84 66 / 20 10 10 30 MCALLEN 78 69 86 65 / 30 10 0 20 RIO GRANDE CITY 77 66 86 63 / 30 0 0 10 SOUTH PADRE ISLAND 77 73 80 73 / 20 10 10 40 BAYVIEW/PORT ISABEL 78 68 83 70 / 20 10 10 40

BRO WATCHES/WARNINGS/ADVISORIES

TX...High Rip Current Risk through Saturday afternoon for TXZ451-454- 455.

GM...Small Craft Advisory until 6 PM CST Saturday for GMZ130-132-135- 150-155-170-175.