Port Fourchon Louisiana to Lower Atchafalaya River Louisiana Marine Forecast
| Tonight...Southeast Winds 5 To 10 Knots, Becoming East Late. Seas 2 To 3 Feet. Wave Detail: Southeast 3 Feet At 8 Seconds. A Chance Of Showers Until Early Morning, Then A Slight Chance Of Showers Late. |
| Thursday...East Winds 5 To 10 Knots. Seas 2 To 3 Feet. Wave Detail: Southeast 3 Feet At 8 Seconds. A Slight Chance Of Showers In The Morning. |
| Thursday Night...Southeast Winds 5 To 10 Knots. Seas Around 2 Feet. Wave Detail: Southeast 2 Feet At 7 Seconds. A Slight Chance Of Showers. |
| Friday...East Winds 5 To 10 Knots. Seas 1 To 2 Feet. Wave Detail: Southeast 2 Feet At 7 Seconds. A Chance Of Showers. |
| Friday Night...East Winds 10 To 15 Knots. Seas 2 To 3 Feet. Wave Detail: Southeast 3 Feet At 5 Seconds. A Chance Of Showers. |
| Saturday...East Winds 10 To 15 Knots With Gusts Up To 20 Knots. Seas 2 To 3 Feet. Wave Detail: East 3 Feet At 4 Seconds. A Chance Of Showers. |
| Saturday Night...Southeast Winds 10 To 15 Knots, Becoming Northwest After Midnight. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: West 3 Feet At 4 Seconds And Southeast 3 Feet At 5 Seconds. Showers Likely. |
| Sunday...North Winds 15 To 20 Knots. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: Northwest 4 Feet At 4 Seconds And Southeast 2 Feet At 5 Seconds. A Slight Chance Of Thunderstorms. Showers, Mainly In The Morning. |
| Sunday Night...North Winds 15 To 20 Knots, Increasing To 20 To 25 Knots After Midnight. Seas 2 To 4 Feet, Occasionally To 5 Feet. Wave Detail: Northwest 4 Feet At 4 Seconds And Southeast 1 Foot At 6 Seconds. A Chance Of Showers, Mainly In The Evening. |
| Monday...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: North 3 Feet At 3 Seconds. A Slight Chance Of Showers In The Morning. |
| Monday Night...North Winds 15 To 20 Knots. Seas 2 To 4 Feet, Occasionally To 5 Feet. Winds And Seas Higher In And Near Thunderstorms. |
| Area Forecast Discussion National Weather Service New Orleans LA 118pm CST Wednesday Jan 21 2026 .SHORT TERM... (This evening through Friday night) Issued at 1213pm CST Wednesday Jan 21 2026 No significant changes from the previous forecast overall through Friday night. The Gulf South region will remain embedded beneath a zonal flow pattern in the mid and upper levels. At the same time, a persistent onshore flow regime will be in place in the low levels. This onshore flow pattern will continue to advect in a warm and humid airmass, and this will keep temperatures well above average through Friday. Highs will climb into the upper 60s and lower 70s each day, and overnight lows will only dip into the low to mid 50s. Late Friday night, a backdoor cold front will begin to move into the area, and this will help to lower temperatures slightly for areas north of I-10 with readings falling into the 40s. A fast moving shortwave trough and associated 120 knot jet streak will pass through the Lower Mississippi Valley this afternoon into tonight. The system will start to shift to the east by tomorrow morning. Favorable upper level dynamics from the region being in the entrance region of the jet streak and the increasing positive vorticity advection associated with the passing trough will produce ample forcing in the mid and upper levels. This forcing will tap into the moderately unstable and very moist environment to produce periods of light rainfall through the overnight hours. As the trough axis departs tomorrow morning, increasing negative vorticity advection and upper level subsidence will begin to take hold. This will help to suppress rain chances through Thursday night with only some low topped and very isolated shower activity anticipated. Friday will see a bit higher rain chance as another weak area of enhanced vorticity slips through, but the activity will remain light and very scattered due to the lack of any low level forcing mechanisms nearby and a continued strong mid-level capping inversion. However, as we move into late Friday night, rain chances will start to increase across the northern third of the CWA (County Warning Area) as the backdoor cold front starts to push in. Increasing isentropic forcing over a shallow cold pool(a region of relatively cold air) will support a region of light stratiform rain formation by daybreak on Saturday across southwest Mississippi and portions of the Florida Parishes. Long Term (Saturday through Tuesday night) Issued at 1213pm CST Wednesday Jan 21 2026 The medium range guidance has started to come into better agreement today with smaller temporal and spatial model spread and less temperature spread between the 25th and 75th percentiles in the NBM. That being said, the forecast is still highly dependent on exactly how far south the freezing temperature line can get Saturday night into Sunday morning, and there will be a very sharp thermal gradient across the forecast area as the initial backdoor cold front stalls out. A broad region of isentropically induced rainfall will persist into Saturday across the area as temperatures remain above freezing. However, by Saturday evening, temperatures will start to cool below freezing in southwest Mississippi, and the freeze line will then gradually dip southward toward northern portions of metro Baton Rouge by Sunday morning. The isentropically induced rainfall will turn a bit more heavier Saturday night as another jet streak and increasingly difluent flow aloft increases overall omega values in the region. The one thing of note is that overall probabilities of freezing rain accumulation have stayed steady today in the NBM with the chance of ice accumulation remaining between 40 and 60 percent for locations in southwest Mississippi and the Felicianas. This continues to be the most likely area to see ice accumulation occur, and the forecast has changed little from before in terms of the freezing rain location. Further to the south, temperatures are projected to remain above freezing, so it will be a rain event for the Northshore, Southshore, and coasts of Louisiana and Mississippi this weekend. One other thing we are starting to be a bit concerned about is the potential for strong to severe thunderstorms impacting areas along the immediate coast of Louisiana and the offshore waters where surface based instability and very strong directional shear parameters could be in place. This will be highly dependent on the exact track of a surface based low pressure system that is projected to move through the area on Saturday. Conditions will quickly dry out on Sunday as a surge of drier air and strong negative vorticity advection in the wake of a passing strong longwave trough overspreads the Gulf South. Lingering precipitation is expected in the morning hours, but conditions will quickly dry out from west to east in the afternoon hours, and expect to see dry conditions at all locations over land by the evening hours. Along with the increasing dry air advection, an extremely cold arctic airmass will begin to feed into the region. Highs will peak in the morning hours with temperatures falling in the afternoon hours as the arctic air moves in. This will keep highs in the 30s over the northwest third of the CWA and the 40s and lower 50s along the coast. Extremely cold conditions will then be in place from Sunday night through Tuesday night and extreme cold headlines will be in place during this period of time. Lows will fall into the teens north of I-12 and the mid 20s further south. Winds will remain gusty, so wind chills will dip into the single digits and teens. Highs will only climb into the upper 30s and lower 40s Monday afternoon, and temperatures will plunge back into the teens and 20s Monday night. Some modification in the airmass will take place on Tuesday as the heart of the arctic airmass starts to shift away, but temperatures will still be a good 15 to 20 degrees below average with readings in the 40s during the day and the 20s Tuesday night. Marine Issued at 1213pm CST Wednesday Jan 21 2026 Persistent east winds of 10 to 15 knots will remain in place through Friday night. A low pressure system is expected to pass through the waters Saturday into Saturday night. The easterly winds will turn more southeasterly and increase to 15 to 20 knots or exercise caution range as this low tracks through the waters. In the wake of the low, a strong cold front will sweep across all of the coastal waters on Sunday. Winds will shift to the northwest and quickly ramp up to 20 to 25 knots by Sunday afternoon. These small craft advisory conditions will persist into Monday. NOAA New Orleans LA Office: Watches - Warnings - Advisories LA...None. GM...None. MS...None. GM...None. |
New Orleans LA Radar
Gulf Radar