Marine Weather Net

Lake Pontchartrain and Lake Maurepas Marine Forecast


15 - 20




10 - 15


5 - 10

The Marine Weather Forecast In Detail:
GMZ530 Forecast Issued: 1011 AM CDT Fri Sep 29 2023

Rest Of Today...East Winds 15 To 20 Knots. Waves 2 To 3 Feet.
Tonight...East Winds Near 15 Knots, Diminishing To 10 Knots After Midnight. Waves 2 To 3 Feet.
Saturday...East Winds 10 To 15 Knots. Waves 2 To 3 Feet.
Saturday Night...East Winds 5 To 10 Knots. Waves 2 To 3 Feet.
Sunday...East Winds 10 To 15 Knots. Waves 2 To 3 Feet.
Sunday Night...East Winds 10 To 15 Knots. Waves 2 To 3 Feet.
Monday...East Winds 10 To 15 Knots. Waves 2 To 3 Feet.
Monday Night...East Winds 10 To 15 Knots, Diminishing To 5 To 10 Knots After Midnight. Waves Around 2 Feet.
Tuesday...East Winds 10 To 15 Knots. Waves 2 To 3 Feet.
Tuesday Night...East Winds 5 To 10 Knots. Waves Around 2 Feet.
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Area Forecast Discussion
National Weather Service New Orleans LA
707am CDT Fri September 29 2023

Long Term
(Sunday night through Thursday) Issued at 431am CDT Fri September 29 2023

As we have said the last few days confidence continues to grow and remains very high given the almost perfect agreement between the medium range models and their respective ensemble means. The continuity and consistency has been rather impressive but it also means we are rather confident we will remain dry through at least Wednesday next week if not through the entirety of the forecast. Fingers crossed though as the models are still trying to indicate a strong cold front late next week into the weekend. There are some timing issues between the models but they all at least have something in the extended just outside our current forecast.

The ridge that will be building and dominating our weather through the weekend will still be in place. The pattern is not a favorable one for any quick changes due to a highly amplified trough over the west, and equally amplified ridge in the center, and a large but not as deep L/W trough just off the Atlantic coast. This means that the ridge will likely control our weather through the first half of the work week. Not until something can erode the ridge or the ridge breaks through the eastern trough will things progress. And it is exactly that which seems to be the case mid to late next week. As the western CONUS trough's jet starts to round the base of it overnight Sunday and through Monday it will finally stop digging and start to slowly work east bumping up against the ridge. The mid level jet then starts to move downstream of the trough causing parts of the the trough to want to lift to the northeast and begin to erode and nudge the northern half of the ridge. As that occurs the northern portions of the ridge will try to start to pinch in and break through the western Atlantic trough. Again this is all going to be slow and likely take 2-3 days to occur but finally by Wednesday the western CONUS L/W should finally be moving across the Rockies however the base of that trough gets blocked to the south by the core of where our ridge originated, across northern Mexico. With that the ridge still dominating the area and the ridge axis taking on a very pronounced positive tilt and extending across our area and into the northeastern CONUS. This just continues the status quo of no rain and keeps us in the dry mild to slightly above normal temps. Finally by Thursday the L/W trough should have sufficiently broken down the ridge enough to finally enter the central CONUS. Again not much will likely change for our sensible weather through Wednesday as the Mexican ridge will still be strong causing the base of the trough to abrupartly end before it reaches the US/Mexico border. And the other problem that starts to develop is there is a good chance that a Rex block sets up over the Atlantic coast as our old ridge finally breaks through the western Atlantic trough causing the base of the trough to cut off north of the Bahamas and the ridge to become centered over the patriot states. This blocking setup starts to lead to the central CONUS trough becoming positively tilted a little however, it is still slowly working east and thus the base of the trough begins to round the top of the Mexican ridge finally leading to weak southwest flow aloft and maybe a return of moisture and eventually maybe some showers on Friday. /CAB/

Issued at 431am CDT Fri September 29 2023

Strong easterly winds continune across the coastal waters and may continue through the weekend. Pressure gradient of 3 to 4 mb will be persistent through the weekend due to a large strong area of high pressure to our northeast. The high will be centered over the Great Lakes by Saturday morning but it along with weak low pressure in the southwestern Gulf will keep that gradient in place. SCY continues for all waters through today and then for all of the waters except the tidal lakes (this includes Lake Borgne) thourgh 9z. Will allow the day shift to see where the SCY needs to be extended into the weekend if it needs to be.

The persistent moderate to strong easterly winds will get the seas/waves up to 3-6 ft but the other issue continues to be the small risk of coastal flooding from water piling up on east facing shores. Tides overachieved yesterday but as we finally move into the heart of the neap tide we should see high tide just below where we would need an advisory for today. Tomorrow should be similar but heading into Sunday and Monday the easrterly winds will not quit. They may not be quite as strong but with 4-5 days now of easterly winds the water will have sufficiently piled up along the coast. This will combine with the area quickly coming out of neap tide and the astronimcal tide range increasing to 1.3 to 1.5' at Shell Beach and Waveland. If we are still seeing tides run about 1.5' ft above normal we will need advisories out for high tide on Sunday and Monday. /CAB/

NOAA New Orleans LA Office: Watches - Warnings - Advisories
LA...None. GM...Small Craft Advisory until 3pm CDT this afternoon for GMZ530- 532-534.

Small Craft Advisory until 4am CDT Saturday for GMZ536-538-550- 552-555-557-570-572-575-577.

MS...None. GM...Small Craft Advisory until 3pm CDT this afternoon for GMZ532- 534.

Small Craft Advisory until 4am CDT Saturday for GMZ538-550-552- 555-557-570-572-575-577.