textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 527 AM CST Mon Dec 1 2025

* Roller-coaster temperature pattern expected to take place through next weekend.

* Another cold front arrives Thursday night into Friday with showers and thunderstorms developing Thursday through Friday.

* Adverse to hazardous marine conditions to persist through at least Tuesday.

DISCUSSION

Issued at 1053 PM CST Sun Nov 30 2025

Progressive/changeable weather pattern featuring multiple temperature swings, and another cool front that will bring more widespread chances for showers and thunderstorms Thursday into Friday is expected to take place during the forecast period or through next Monday. Mainly cloudy skies will dominate the week ahead.

Through tonight, blustery northerly winds 10-20 mph with gusts as high as 30 mph will help to usher in the coldest airmass of the season (since last February). Despite an abundance of cloud cover in place to help with insolation, a full cold air advection regime in place over the region will result in overnight low temperatures falling into the 40s most places (50s along mid to lower valley and the coast). Latest radar scans show most of the rain showers over the Gulf Waters, but through tonight, there could be some lingering vicinity showers/sprinkles around, especially areas near the coast. Mist is also possible to due to residual low level moisture underneath an inversion. Again, this is especially true for areas near the coast. Otherwise, expect for a cool, rain-free, blustery night ahead.

Monday through Tuesday night, it still will remain cool though there will be a gradual moderation in temperatures. On Monday daytime highs will struggle to make it out of the 50s most places. On Tuesday, daytime highs will struggle to make it out of the 60s. Monday night, overnight lows will fall into the 40s across much of Deep South Texas (50s along the RGV). Tuesday night, lows will be in the 50s most places. There could be a few lingering sprinkles/showers around on Monday, but most areas will remain rain- free under mostly cloudy skies.

Warmer than normal temperatures arrive on Wednesday and continue into Thursday as a return flow develops out of the south-southeast. High temperatures on Wednesday and Thursday will climb into the lower 80s along the RGV and 70s across the Northern Ranchlands. Wednesday night, overnight lows will be in the 60s most places (lower 70s across parts of the RGV).

Thursday night into Friday, forecast models/ensembles are depicting another cool front that is set to sweep through Deep South Texas and the RGV. Ahead of the cool fropa, some overrunning combined with increased sfc convergence and instability will result in the development of showers and thunderstorms across Deep South Texas and the RGV Thursday into Thursday night. Coverage is expected to be more widespread and showers/thunderstorms more robust than what occurred earlier today. Lingering showers are possible on Friday through Friday night behind the cool fropa. Currently , we have low to medium (20-60%) chance PoPs Thursday-Thursday night with the higher probabilities closer to the coast. Even higher (70-80%) PoPs are expected over the Gulf Waters. Friday-Friday night, we have low to medium (20-40%) chance PoPs for lingering, post-frontal showers with the highest chances again being near the coast.

Daytime highs on Friday is progged to be in the 60s most places (lower 70s across parts of the RGV). Temperatures moderate/warm once again Saturday and Sunday. Highs on Saturday will be in the 70s most places and on Tuesday 80s most places. By Monday, highs are expected to be in the 70s most places. Thursday night through Monday night, lows will be in the 50s most places (lower 60s along the RGV Saturday night through Monday night).

AVIATION

(12Z TAFS) Issued at 527 AM CST Mon Dec 1 2025

MVFR conditions prevail for much of the 12Z TAF cycle at all sites under a blanket of BKN to OVC stratus at 010-020. North- northwesterly winds will gradually diminish early Monday to around 10kts. Light precip moving north this morning and again late tonight may bring brief, light rain or drizzle to all sites, with highest chances (30%) at BRO.

MARINE

Issued at 1053 PM CST Sun Nov 30 2025

Adverse to hazardous marine conditions are expected to persist through Tuesday. A Small Craft Advisory has been extended to noon CST Monday. Small Craft Exercise Caution (SCEC) conditions will then take place on Monday. However, another Small Craft Advisory may be needed Monday night into Tuesday. Beyond Tuesday, marine conditons are expected to improve with light to moderate seas and light to moderate winds and seas persisting through Thursday. A cold front pushes through Thursday night into Friday and that could result in more adverse marine conditions developing.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 60 53 61 58 / 20 30 20 10 HARLINGEN 58 49 61 54 / 20 20 10 0 MCALLEN 59 51 61 57 / 20 20 10 0 RIO GRANDE CITY 60 50 63 53 / 10 10 10 0 SOUTH PADRE ISLAND 64 60 64 64 / 30 40 20 10 BAYVIEW/PORT ISABEL 60 53 62 58 / 30 30 10 10

BRO WATCHES/WARNINGS/ADVISORIES

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

GM...Small Craft Advisory until noon CST today for GMZ130-132-135-150- 155-170-175.