Marine Weather Net

Port Fourchon Louisiana to Lower Atchafalaya River Louisiana Marine Forecast


TONIGHT

S
WINDS
15 - 20
KNOTS

SUNDAY

NW
WINDS
15 - 20
KNOTS

SUNDAY NIGHT

N
WINDS
15 - 20
KNOTS

MONDAY

NE
WINDS
15 - 20
KNOTS

The Marine Weather Forecast In Detail:
GMZ550 Forecast Issued: 340 PM CST Sat Feb 15 2025

SMALL CRAFT ADVISORY IN EFFECT THROUGH SUNDAY MORNING ...SMALL CRAFT EXERCISE CAUTION IN EFFECT SUNDAY AFTERNOON...
Tonight...South Winds 15 To 20 Knots, Becoming Southwest 20 To 25 Knots Late This Evening And Early Morning, Then Becoming West Late. Gusts Up To 35 Knots. Seas 4 To 6 Feet, Occasionally To 8 Feet. Wave Detail: South 6 Feet At 7 Seconds. A Slight Chance Of Showers Early This Evening, Then A Chance Of Showers With A Slight Chance Of Thunderstorms Late This Evening. Showers With A Chance Of Thunderstorms After Midnight.
Sunday...Northwest Winds 15 To 20 Knots With Gusts Up To 30 Knots. Seas 3 To 5 Feet, Occasionally To 6 Feet. Wave Detail: Southwest 5 Feet At 7 Seconds And Northwest 3 Feet At 4 Seconds.
Sunday Night...North Winds 15 To 20 Knots With Gusts Up To 25 Knots. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: Northwest 3 Feet At 4 Seconds And Southeast 3 Feet At 7 Seconds.
Monday...Northeast Winds 15 To 20 Knots With Gusts Up To 25 Knots, Becoming East 10 To 15 Knots In The Afternoon. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: East 2 Feet At 2 Seconds And Southeast 2 Feet At 7 Seconds.
Monday Night...East Winds 10 To 15 Knots. Seas 2 To 3 Feet. Wave Detail: East 2 Feet At 3 Seconds And Southeast 1 Foot At 7 Seconds.
Tuesday...East Winds 10 To 15 Knots, Increasing To 15 To 20 Knots In The Afternoon. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: Southeast 4 Feet At 6 Seconds. A Slight Chance Of Showers In The Morning, Then A Chance Of Showers In The Afternoon.
Tuesday Night...Southeast Winds 15 To 20 Knots, Becoming South After Midnight. Seas 3 To 5 Feet, Occasionally To 6 Feet. Wave Detail: Southeast 5 Feet At 6 Seconds. Showers With A Chance Of Thunderstorms.
Wednesday...Northwest Winds 15 To 20 Knots, Becoming North 20 To 25 Knots In The Afternoon. Seas 3 To 5 Feet, Occasionally To 6 Feet. Wave Detail: South 5 Feet At 7 Seconds And Northwest 4 Feet At 4 Seconds. Showers Likely With A Chance Of Thunderstorms In The Morning, Then A Slight Chance Of Showers And Thunderstorms In The Afternoon.
Wednesday Night...North Winds 20 To 25 Knots. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: Northwest 3 Feet At 3 Seconds And South 2 Feet At 7 Seconds. A Slight Chance Of Thunderstorms In The Evening. A Slight Chance Of Showers.
Thursday...North Winds 20 To 25 Knots, Diminishing To 15 To 20 Knots In The Afternoon. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: South 1 Foot At 7 Seconds.
Thursday Night...Northeast Winds 15 To 20 Knots. Seas 2 To 4 Feet, Occasionally To 5 Feet. Winds And Seas Higher In And Near Thunderstorms.
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Area Forecast Discussion
National Weather Service New Orleans LA
331pm CST Sat Feb 15 2025

.SHORT TERM... (Tonight through Sunday night) Issued at 108pm CST Sat Feb 15 2025

Biggest concern in the short term concerns the potential for severe weather this evening and into tonight. A line of showers and thunderstorms is taking shape ahead of a cold front that currently stretches from southern Arkansas south/southwestward through southern Texas. The front and associated showers and thunderstorms will move southeastward through the remainder of the afternoon, with the main line of storms expected to be on the doorstep of our local area shortly after sunset.

The line will progress through the local area generally between 10p and 4a, and Storm Prediction Center continues to highlight the entire area with at least a Slight Risk (level 2 of 5) of severe weather. The greatest threat will be generally north of the I-10/12 corridor where SPC has highlighted an Enhanced Risk (level 3 of 5). The main threat from any severe storms will be damaging wind gusts, especially in any bowing segments along the line. However, as is normally the case, a few tornadoes embedded in the line will also be possible. Hail looks unlikely based on temperatures aloft, and the line should be moving fast enough to preclude any significant heavy rain threats. While the main threat will accompany the line as it moves through the area, there is some potential for a few strong to severe storms forming out ahead of the line mainly in the 6p-10p time frame, and in areas west of the I-55 corridor. These discrete cells out ahead of the line would have a slightly higher chance of producing tornadoes if they can develop robust updrafts.

By daybreak, the cold front should be into the Gulf with cooler and drier air building into the area. Highs tomorrow are generally forecast to top out in the lower 60s, which is actually a couple degrees cooler than normal for this time of year. The cooler high pressure will settle over the area tomorrow night and temperatures will plummet after sunset, as dry air, clear skies, and light to calm winds allow efficient radiative cooling.

A brief period of freezing temperatures is forecast for portions of southwestern Mississippi around daybreak Monday, and if this forecast holds, a freeze watch/warning may need to be issued given the substantial warm period we've been experiencing.

Long Term
(Monday through Friday night) Issued at 108pm CST Sat Feb 15 2025

High pressure will quickly shift eastward on Monday, with winds turning east or southeasterly by Monday afternoon as another frontal system takes shape northwest of the local area. This next system doesn't appear to pose much of a severe weather threat, owing to the fact that the more unstable air should remain offshore, but with a quasi-stationary boundary near the coast and decent moisture return above the surface, locally heavy rain could become a threat, though the area of greatest threat will depend on where exactly the boundary sits, and how it interacts with a developing surface low. Current thinking is that the heaviest rain will remain just offshore, but storm totals in the 1-2 inch range seem reasonable at this time, with some potential for higher totals if the boundary moves a bit farther north.

The surface cold front will sweep through the local area late Tuesday night into Wednesday, bringing much colder air into the area. The upper trough and airmass behind the front are not yet being well sampled, but it does look like some arctic air may spill southward with this front. Will start by saying that while it will certainly be cold, we're not talking about the same kind of cold experienced in January. That was an exceptionally cold air mass, aided by snow cover even at the local level (hard to believe it's been less than a month since that happened).

There continue to be questions regarding exactly how cold it will be following the front and there are still some fairly large differences both between the different models and model ensemble members. However, will mention that the overall spread in the guidance has been getting smaller, with some of the colder members coming in not quite as cold anymore. In fact, the 12z ECMWF (European Centre for Medium-Range Weather Forecasts) ensemble mean is a solid 5-7 degrees warmer across most of our northern areas for Thursday and Friday mornings. This puts it closer to, but still several degrees cooler than the GFS. Given the trend in the Euro ensemble guidance, and knowing that the latest NBM does not yet reflect this trend, am carrying temperatures that are generally 3-5 degrees warmer than the NBM for Thursday and Friday mornings with this update. This still results in fairly widespread freezing temperatures for areas generally along/north of the I-10 corridor and some potential for hard freeze conditions across southwestern Mississippi and the adjacent LA parishes.

With the substantial greening that has occurred over the last couple weeks (hello pollen season), crops and other sensitive vegetation will be more susceptible to these cold temperatures, and any forecast freezing temperatures will prompt the issuance of freeze watches/warnings and/or cold weather advisories.

Marine
Issued at 108pm CST Sat Feb 15 2025

Strong onshore winds will persist through tonight until a cold front sweeps through the waters, shifting winds to the northwest and then north. The front will also be accompanied by showers and thunderstorms, some of which could become strong to severe. While gale force gusts will be possible, think they will be relatively short lived and mostly associated with connection, so have held off on a gale warning and left the previously issued small craft advisories in place. Winds will gradually ease beginning Sunday afternoon and into Sunday night as high pressure settles into the area. But the high will shift eastward quickly on Monday with return flow once again setting in by Monday afternoon ahead of another front forecast to affect the area midweek.

NOAA New Orleans LA Office: Watches - Warnings - Advisories
LA...Wind Advisory until midnight CST tonight for LAZ034>037-039- 046>048-056>060-064>071-076>090.

GM...Small Craft Advisory until 9am CST Sunday for GMZ530-550-552- 570-572.

Small Craft Advisory from 9pm this evening to 9am CST Sunday for GMZ532-534-536-538-555-557-575-577.

MS...Wind Advisory until midnight CST tonight for MSZ068>071-077- 083>088.

GM...Small Craft Advisory until 9am CST Sunday for GMZ550-552-570- 572.

Small Craft Advisory from 9pm this evening to 9am CST Sunday for GMZ534-536-538-555-557-575-577.