Marine Weather and Tide Forecast for Port Isabel, TX

DISCUSSION
Issued at 1216 PM CST Sun Dec 14 2025

A cold front has worked its way across Deep South Texas this morning, leaving cooler temperatures, gusty winds, showers, and coastal hazards in its wake. Showers against the front are currently moving past the Rio Grande River, and will continue to move south of the region through the afternoon. Dry air behind the front will keep rain chances low for late Sunday afternoon onwards, but an isolated shower or two cannot be ruled out. Gusty northerly winds from 15-25 mph gusting 20 to around 40 mph will continue through the afternoon, beginning to lessen overnight.
Stronger, gustier winds will be nearer the coast.

Coastal hazards behind the cold front include a Coastal Flood Statement, in effect from 12 PM Sunday to midnight, a High Surf Advisory from 3 PM Sunday to 6 AM Monday, and a High Risk of Rip Currents through 6 PM Monday. Despite astronomically low tides and a waning crescent moon, strong northerly winds behind the front will build seas and may cause narrow beaches and runup.

Temporary relief in temperatures following cold fropa, with near to just below average temps through Monday. High temperatures were reached this morning as cold air advection begins to drain cooler air into the CWA, dropping temperatures through the overnight.
Monday morning low temperatures in the 40s, 50s along the immediate coast and RGV. Mostly cloudy skies Monday morning begin to break up through the afternoon, with high temperatures in the 60s.

Dry air behind the front will keep rain chances low (20% or less)
through Tuesday, when southeasterly flow returns moisture into the atmosphere. An approaching disturbance midweek will elevate rain chances Tuesday night through Wednesday - moderate along the coast and low inland.

In the latter half of the week, a zonal synoptic setup is expected to dominate, leaving benign weather and a chance for warm temperatures to rise to above average.

AVIATION
(00Z TAFS)
Issued at 505 PM CST Sun Dec 14 2025

MVFR ceilings this evening are currently ranging from around 1,200 ft at KBRO, 1,300 ft at KHRL and 1,500 ft at KMFE along with northerly winds of 15-20 knots, gusting to 25-30 knots. These conditions are likely to prevail through at least 06Z tonight, though ceilings may briefly drop to IFR at KBRO, perhaps at KHRL as well. Winds steadily improve overnight to around 10-15 knots by sunrise tomorrow, further winding down and remaining out of the north throughout the daytime as MVFR ceilings gradually rise, possibly becoming scattered in the afternoon.

MARINE
Issued at 1216 PM CST Sun Dec 14 2025

Unfavorable marine conditions are in place behind a cold front passage Sunday morning. Strong to near gale northerly winds with gusts to gale force will continue Sunday afternoon and ahead of sunrise Monday. Seas build to rough Sunday afternoon and persist overnight, decreasing during Monday. Moderate winds turn southeasterly Tuesday and continue through much of the week.
Isolated to scattered showers and thunderstorms diminish Sunday evening as dry air enters behind the front. Low chances of rain continue until Tuesday evening, when medium to high (40 to 70 percent) chances return through Wednesday. Favorable conditions to persist Tuesday through late week.

PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 50 66 56 76 / 20 10 0 20 HARLINGEN 47 64 52 75 / 10 0 0 10 MCALLEN 50 65 55 73 / 20 0 0 20 RIO GRANDE CITY 47 64 51 71 / 10 0 0 20 SOUTH PADRE ISLAND 59 65 61 73 / 30 10 0 20 BAYVIEW/PORT ISABEL 51 65 55 76 / 20 0 0 20

BRO WATCHES/WARNINGS/ADVISORIES
TX...High Rip Current Risk through Monday afternoon for TXZ451-454- 455.

High Surf Advisory until 6 AM CST Monday for TXZ451-454-455.

GM...Small Craft Advisory until 6 AM CST Monday for GMZ130-132-135.

Gale Warning until 6 AM CST Monday for GMZ150-155-170-175.