Marine Weather Net

Port Mansfield, TX to the Rio Grande River Marine Forecast


TODAY

SE
WINDS
20
KNOTS

TONIGHT

SE
WINDS
15 - 20
KNOTS

SATURDAY

SE
WINDS
10 - 15
KNOTS

SATURDAY NIGHT

SE
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
GMZ150 Forecast Issued: 355 AM CDT Fri Mar 29 2024

SMALL CRAFT ADVISORY IN EFFECT FROM 11 AM CDT THIS MORNING THROUGH THIS EVENING
Today...Southeast Winds Around 20 Knots. Gusts To 30 Knots This Afternoon. Seas 4 To 6 Feet, With Occasional Seas Up To 7 Feet.
Tonight...Southeast Winds 15 To 20 Knots. Gusts To 30 Knots In The Evening. Seas 4 To 5 Feet.
Saturday...Southeast Winds 10 To 15 Knots Increasing To 15 To 20 Knots In The Afternoon. Seas 3 To 4 Feet.
Saturday Night...Southeast Winds 10 To 15 Knots. Seas 3 To 4 Feet.
Sunday...South Winds 10 To 15 Knots Becoming Southeast 15 To 20 Knots With Gusts Up To 30 Knots In The Afternoon. Seas 4 To 5 Feet.
Sunday Night...Southeast Winds 20 To 25 Knots With Gusts Up To 30 Knots. Seas 4 To 5 Feet.
Monday...South Winds 20 To 25 Knots Decreasing To 15 To 20 Knots In The Afternoon. Seas 5 To 7 Feet, With Occasional Seas Up To 8 Feet.
Monday Night...Southeast Winds 15 To 20 Knots Becoming South 10 To 15 Knots After Midnight. Seas 5 To 7 Feet, With Occasional Seas Up To 8 Feet Subsiding To 4 To 5 Feet After Midnight.
Tuesday...North Winds 10 To 15 Knots. Seas 4 To 5 Feet.
Tuesday Night...North Winds 10 To 15 Knots Increasing To 15 To 20 Knots With Gusts Up To 30 Knots After Midnight. Seas 5 To 7 Feet, With Occasional Seas Up To 8 Feet.
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Area Forecast Discussion
...UPDATED National Weather Service Brownsville TX
630am CDT Fri Mar 29 2024

Long Term
(Saturday night through Thursday) Issued at 413am CDT Fri Mar 29 2024

Key Messages:

- Becoming Windy Sunday-Monday (southerly winds 20-30 mph with higher gusts)

- Very Warm to Hot Sunday-Monday (widespread 90s and 100s)

Changeable weather pattern during the long-term forecast period featuring a big warm up and windy conditions at the beginning of the period to temperatures returning closer to normal levels during the second half of the period.

We start off the long-term period Saturday night where aloft the 500 mb setup will feature an amplified pattern with an anomalously strong low/trough over the Southwestern CONUS and a resultant downstream ridge over the southern and eastern two-thirds of the CONUS with the ridge axis placed over the Gulf Coast states.

Saturday night into Sunday, a surface pressure gradient is expected to intensify over the region with a surface lows over the southern High Plains and at times north central Mexico interacting with a surface high over the Gulf of Mexico. Forecast models are indicating H850 (low level jet) winds intensifying over the region Sunday afternoon and persisting into Monday. Low level jet winds during this timeframe were sampled between 35-45 kts over the region with the strongest of winds east of I-69. All of this coupled with increased mixing heigheights Sunday afternoon through Monday will result in breezy to windy conditions Sunday and Monday with southerly winds at the surface sustained between 20-30 mph and gusting up to 40 mph. Wind Advisories may be needed considering the strong winds aloft and the local/climate effects over the Rio Grande Valley (can see wind gusts being higher than 40 mph Sunday and/or Monday). Will have to keep monitoring trends in the days ahead.

A strong return flow in the lower levels out of the south will result in adequate warm air advection during the day on Sunday and Monday. On Monday, 850 mb winds are expected to switch out of the west. Enhancements due to compressional heating with air moving down the slopes of the Sierra Madre Oriental could result in a heat spike over the region on Monday. That said, current thinking is that daytime highs will get into the upper 80s to near 100F degrees over Deep South Texas with the hottest temps over the western parts of the area. On Monday, daytime highs are projected to be even warmer with values in the 90s to 100s (hottest readings or widespread triple digit readings once again over the western half of the area).

On Tuesday, forecast models and ensembles show the large scale pattern breaking down (i.e. becoming less amplified with troughing over the western U.S. translating eastward. Near the surface a cold frontal boundary is expected to pass over the area on Tuesday. Still some uncertainty as to the exact timing of the frontal boundary. However, consensus shows that temperatures will have enough time to warm into mid/upper 80s to near 90F across the area before passing through. The cold front will be moisture starved, so no precipitation is expected.

Following the cold frontal passage. a welcomed drier and cooler airmass will take hold over the area. Tuesday night, overnight low temperatures are forecast to be in the upper 50s to lower 60s (a notable relief for residence of Deep South Texas and the Rio Grande Valley). With a full dry and cool air advection regime in place, Wednesday will be a pleasant day with highs only reaching the upper 70s to lower 80s. Thursday and Friday will be slightly warmer and closer to normal with highs in the low to mid 80s.

Marine
Issued at 413am CDT Fri Mar 29 2024

Now through Saturday...Adverse conditions will develop along portions of the Lower Texas Coast this morning. A Small Craft Advisory remains in effect for the Laguna Madre beginning at 16Z until 01Z Saturday due to the strengthening southeasterly gradient flow. The latest DESI supports higher wind probabilities over the nearshore Gulf waters. Therefore, have issued a Small Craft Advisory for the nearshore GUlf waters (0-20 nm during this same timeframe as the Laguna Madre (16z until 01Z). Exercise Caution conditions will prevail across the remainder of the coastal waters today and across the waters tonight and Saturday. Seas will continue to slowly respond and build to 4-6 feet by tonight due to the moderate to occasionally strong southeast flow.

Saturday Night through Friday....Persistent high pressure in place over the Gulf interacting with low pressure systems over the southern High Plains, and to some extent lower pressures over North Central Mexico, will keep a tighter pressure gradient in place over the Lower Texas coastal waters through Monday. A cold front will move through on Tuesday and will shift winds to northwest as high pressure spreads across the region. Moderate to fresh southeast to south winds and moderate to high seas will be the rule most of the early long term. Moderate to fresh winds will carry over from Friday night into Saturday and will persist all the way through Monday. A cold front will push through late Monday or early Tuesday, bringing moderate to fresh northwest to north winds. Overall, small craft should exercise caution conditions will be common to continuous through the period. Low end small craft advisory conditions may additionally develop from time to time due to enhanced winds and/or seas.

NOAA Brownsville TX Office: Watches - Warnings - Advisories
TX...None. GM...Small Craft Advisory from 11am this morning to 8pm CDT this evening for GMZ130-132-135-150-155.