textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1114 AM CST Thu Dec 4 2025

* Dangerous marine and surf conditions are expected through at least tomorrow evening due to today's frontal passage.

* Due to a developing coastal surface low pressure system, a low to medium chance of light rain and drizzle is expected in the coastal counties tonight and tomorrow, with chances spreading to all of Deep South Texas tomorrow night.

* Another front is expected Sunday, which bring dry and pleasant weather to the region next week.

DISCUSSION

Issued at 1114 AM CST Thu Dec 4 2025

Temperatures are expected to continue falling late this evening into tonight after a cold front passes through Deep South Texas this afternoon. Northerly winds will funnel colder air into the region and low temperatures are expected to get down into the upper 40s for the Northern Ranchlands and the lower 50s for the lower Rio Grande Valley tonight. There is a low to moderate chance of stratiform drizzle/light rain overnight, with the highest chances along the immediate coast, extending inland to areas E of I-69E.

A coastal trough is expected to develop in the wake of the cold front, which will keep conditions cloudy through at least Saturday and maintain chances for light rain through tomorrow night. Low to moderate (20-40%) chances will be concentrated mostly along the coast tomorrow, but will spread inland across Deep South Texas tomorrow evening into the overnight hours. High temperatures tomorrow are expected to be cool, getting up into the lower 60s with limited heating due to cloudy skies. Cloud cover will prevent temperatures from dropping too much tomorrow night, with lows being mostly in the mid to upper 50s.

Temperatures will begin to warm into the 70s and possibly even the low 80s for this weekend, before a second cold front passes through on Sunday, dropping Monday high temperatures back into the 60s. Sunday's front is expected to be a dry cold front, and will push the coastal trough off to the east and restore clear to partly cloudy skies back to the area for next week. Because skies will become clearer Sunday night, increased radiational cooling combined with post-frontal CAA will result in chilly lows in the mid to upper 40s for most of Deep South Texas Sunday and Monday night. High pressure is then expected to settle into the region early next week, resulting in rain-free and gradually warming conditions. Highs should be back in the lower 80s by next Thursday.

A high risk of life-threatening rip currents is expected tonight and tomorrow at area beaches.

AVIATION

(18Z TAFS) Issued at 1114 AM CST Thu Dec 4 2025

VFR and MVFR conditions are being observed at at area airports, and could drop to IFR at BRO and HRL by around 21z, whereas MFE is expected to stay MVFR. Conditions should then improve to MVFR this evening between 01z and 03z. Gusty northerly winds are expected

MARINE

Issued at 1114 AM CST Thu Dec 4 2025

A Small Craft Advisory is in effect from 5 PM CST this evening through 12 PM CST Friday afternoon due to elevated winds and waves from a frontal passage. Conditions should then improve later in the day tomorrow and remain favorable until Sunday night when another system passes through the area, increasing the winds and waves again. Small Craft Advisories and/or Small Craft Exercise Caution Conditions will be possible with this second frontal passage as well.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 53 67 58 76 / 40 10 30 10 HARLINGEN 49 65 54 76 / 20 10 30 10 MCALLEN 52 67 58 77 / 10 10 30 10 RIO GRANDE CITY 50 67 55 78 / 10 10 20 0 SOUTH PADRE ISLAND 59 69 66 74 / 50 20 40 10 BAYVIEW/PORT ISABEL 51 68 58 75 / 40 20 30 10

BRO WATCHES/WARNINGS/ADVISORIES

TX...High Rip Current Risk from 6 PM CST this evening through Friday afternoon for TXZ451-454-455.

GM...Small Craft Advisory from 5 PM this afternoon to noon CST Friday for GMZ130-132-135-150-155-170-175.