Marine Weather Net

Stake Island, LA to Southwest Pass of the Mississippi River out 20 - 60 NM Marine Forecast


5 - 10


5 - 10


10 - 15



The Marine Weather Forecast In Detail:
GMZ575 Forecast Issued: 407 PM CDT Sun Sep 25 2022

Tonight...Southeast Winds 5 To 10 Knots, Becoming South After Midnight. Seas Around 2 Feet This Evening, Then 1 Foot Or Less.
Monday...North Winds 5 To 10 Knots. Seas 1 Foot Or Less.
Monday Night...Northeast Winds 10 To 15 Knots, Increasing To 15 To 20 Knots After Midnight. Seas 2 To 4 Feet, Occasionally To 5 Feet. A Slight Chance Of Showers And Thunderstorms Until Early Morning.
Tuesday...Northeast Winds Around 20 Knots With Gusts Up To 25 Knots. Seas 4 To 6 Feet, Occasionally To 8 Feet.
Tuesday Night...Northeast Winds 20 To 25 Knots With Gusts Up To 35 Knots. Seas 5 To 7 Feet, Occasionally To 9 Feet.
Wednesday...Northeast Winds Around 25 Knots With Gusts Up To 40 Knots. Seas 9 To 11 Feet, Occasionally To 14 Feet, Building To 12 To 15 Feet, Occasionally To 19 Feet In The Afternoon.
Wednesday Night...Tropical Storm Conditions Possible.
Thursday...Tropical Storm Conditions Possible.
Thursday Night...Tropical Storm Conditions Possible.
Friday...North Winds 15 To 20 Knots With Gusts Up To 25 Knots. Seas 7 To 9 Feet, Occasionally To 11 Feet, Subsiding To 5 To 7 Feet, Occasionally To 9 Feet In The Afternoon. A Chance Of Showers And Thunderstorms.
Friday Night...North Winds 10 To 15 Knots With Gusts Up To 25 Knots. Seas 3 To 5 Feet, Occasionally To 6 Feet, Subsiding To 2 To 3 Feet After Midnight. A Chance Of Showers And Thunderstorms, Mainly In The Evening. Winds And Seas Higher In And Near Thunderstorms.
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Area Forecast Discussion
National Weather Service New Orleans LA
407pm CDT Sunday September 25 2022

.SHORT TERM... (This evening through Tuesday) Issued at 243pm CDT Sunday September 25 2022

A shortwave upper level trough will continue to move southward and push through our area tonight overnight into Monday. Isolated to scattered showers could be possible along the coastal areas as the front tries to move through this evening and Monday. Overall, there is decent moisture at the surface, but a lack of deep layer moisture content. As a result, generally not expecting widespread rain, but some places could see some rainfall overnight. Some gusty sub-severe (30-60mph) winds could be possible with a strong storm, but it will not be overly likely.

The warm temperatures will persist through Monday, especially for the coastal areas as the front lags a bit. But, generally highs are forecast in the low to mid 90s. Highs were bumped up 1-2 degrees above guidance. The highs have overachieve the last few days, winds will still be fairly calm (<10 mph), and cloud cover will be low. Tuesday, the frontal system will have pushed through and cooler temperatures will arrive in the area with highs on Tuesday forecast to be in the mid 80s with drier conditions (dewpoints in the upper 50s and low 60s. It will actually start to feel like Fall!

Long Term
(Wednesday through Saturday night) Issued at 243pm CDT Sunday September 25 2022

Really not much change to the extended forecast and some details continue to be contingent on the eventual track and intensity of Ian.

Generally speaking, the Wednesday and Thursday timeframe will have pleasant to cool mornings and warm afternoons with lows in the mid to upper 50s north and highs in the low to mid 80s most places. Will mention that the current forecast lows are several degrees higher than most of the MOS guidance. Believe the NBM is trying to account for stronger winds and mixing overnight, and this seems reasonable so have only deviated by a couple degrees. If winds look to calm a bit more than expected Tuesday and Wednesday nights, there is room for a several more degrees of cooling based on the very dry air mass and mostly clear skies. It will be breezy to windy during the day, but more on that later.

For Friday and into next weekend, a very gradual warming and moistening is expected as the air mass slowly modifies. Saw no real reason to stray far from the NBM given uncertainties in the latter part of the forecast for Ian.

Moving on to the details concerning Ian's forecast... It is still forecast to remain well east of our local area and still looks unlikely that we will feel any significant direct impacts from the storm. However, as it is expected to be a large and strong storm, some indirect impacts are accounted for in the local forecast. A tight pressure gradient between surface high pressure to the north and Ian over the eastern Gulf will set up for breezy to windy conditions Wednesday and Thursday. Am currently carrying sustained winds generally in the 17 to 23 mph range and expect gusty conditions especially in the afternoon as mixing brings some stronger winds down from aloft. Winds around 850mb are forecast to be around 35 mph, so we cannot rule out some gusts in that range. May end up needing a wind advisory depending on how things play out.

The latest wind speed probabilities from NHC continue to indicate a low chance (generally 10% or less) of tropical storm force winds across portions of the area, with the highest probabilities across portions of the MS coast and extreme southeast Louisiana. This is slightly lower compared to the forecast from the same time yesterday, but still results in a few zones carrying "tropical storm conditions possible" wording.

Again, while it appears unlikely that Ian will bring significant impacts to the area, it is forecast to be a large storm and some impacts can extend outside the cone. We urge citizens in Southeast Louisiana and Coastal Mississippi to continue monitoring the forecast for changes as a westward shift could still result in some minor impacts across the local area.

Issued at 243pm CDT Sunday September 25 2022

Conditions will remain generally benign through Monday with winds 10kts or less and seas 2 ft or less. A cold front will sweep through the coastal waters Monday night and as high pressure builds in behind it, expect winds and seas to increase. Some of this will be a direct result of the front and some will be a response to the tightening pressure gradient between the high pressure behind the front and Tropical Storm Ian, which is forecast to be a hurricane in the eastern Gulf by Tuesday. Add in swells emanating from the storm, and it's a pretty high confidence forecast of hazardous conditions across the coastal waters for the Tuesday through Friday time frame. The specific details are still a bit murky and have currently capped winds and seas near/below 30 knots and 12-15 feet respectively based on the current forecast for Ian, but those with marine interests should keep a close eye on the forecast as these details could change. Latest forecast indicates headlines may be needed as early as 06z Tuesday, but are most likely from the daylight Tuesday onward. The latest wind speed probabilities from NHC continue indicate around a 20 percent chance of tropical storm conditions across southeastern portions of the coastal waters.

Fire Weather
Conditions that are conducive for the spread of fires are expected on Wednesday. A dry air mass will be in place, and winds will strengthen due to a tightening pressure gradient between high pressure to the northwest and Tropical Storm Ian, which is forecast to be a strong hurricane over the eastern Gulf of Mexico. Currently, relative humidity is expected to drop to around 25 percent Wednesday afternoon, and it could drop even lower as some guidance continues to hint at potential for dewpoints about 2-4 degrees lower than what is currently being carried in the forecast. Winds are currently forecast to be sustained in the 15 to 20 kt range, but with afternoon mixing, expect higher gusts. Combine these factors with the fact that many areas haven't received appreciable rain in a few weeks, and it is a situation that bears monitoring.

NOAA New Orleans LA Office: Watches - Warnings - Advisories
LA...None. GM...None. MS...None. GM...None.