Marine Weather Net

Savannah, GA to Altamaha Sound, GA including Grays Reef National Marine Sanctuary Marine Forecast


TONIGHT

W
WINDS
25 - 30
KNOTS

MON

W
WINDS
20 - 25
KNOTS

MON NIGHT

W
WINDS
20 - 25
KNOTS

TUE

NW
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
AMZ354 Forecast Issued: 722 PM EST Sun Jan 16 2022

GALE WARNING IN EFFECT THROUGH MONDAY MORNING
Tonight...W Winds 25 To 30 Kt With Gusts To 35 Kt. Seas 7 To 9 Ft, Subsiding To 6 To 8 Ft After Midnight.
Mon...W Winds 20 To 25 Kt With Gusts To 35 Kt. Seas 4 To 6 Ft, Subsiding To 3 To 4 Ft In The Afternoon.
Mon Night...W Winds 20 To 25 Kt With Gusts To 30 Kt, Becoming Nw 15 To 20 Kt After Midnight. Seas 3 To 4 Ft, Subsiding To 2 To 3 Ft After Midnight.
Tue...Nw Winds 10 To 15 Kt, Becoming Ne 5 To 10 Kt In The Afternoon. Seas 2 Ft In The Morning, Then Seas 1 Foot.
Tue Night...Se Winds 5 Kt. Seas 1 Foot.
Wed...Sw Winds 5 Kt. Seas 1 Foot.
Wed Night...Sw Winds 5 To 10 Kt. Seas 1 To 2 Ft.
Thu...W Winds 10 Kt. Seas 2 Ft. A Chance Of Showers.
Thu Night...Ne Winds 15 To 20 Kt. Seas 3 To 4 Ft. A Chance Of Showers.
Fri...Ne Winds 15 To 20 Kt. Seas 4 To 6 Ft. A Chance Of Showers.
Fri Night...N Winds 20 Kt. Seas 4 To 5 Ft.
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Area Forecast Discussion
National Weather Service Charleston SC
732pm EST Sunday Jan 16 2022

Synopsis
Deepening low pressure will continue to move northeast and away from the forecast area. Cold high pressure will build into the region Monday and Tuesday, moving offshore Wednesday. A reinforcing cold front will move through the area Thursday. A coastal low pressure system could impact the area next weekend.

Near Term - Until 6am Monday Morning
Deep low pressure will track NE along the NC coast this evening and mid-Atlantic tonight. As the low departs, WSW winds should strengthen with gusts between 25-30 kts. These winds will remain Wind Advisory criteria, the advisory will be cancelled with this update. Early this evening, KCLX detected a few patches of weak returns across Screven and Allendale Counties, likely associated with sprinkles or light rain. The sprinkles or light rain may continue for the next hour or two. Temperatures may slow cool early this evening, then cooling should increase after midnight with the passage of wrap- around moisture/mid- level trough. Low temperatures are forecast to range in the lower to mid 30s inland to the upper 30s across the coastal counties.

Short Term - 6am Monday Morning Through Wednesday
Monday and Monday night: Aloft, another shortwave trough will swing through the Southern Appalachians and then push offshore into the evening. At the surface, the forecast area will start off the day within the large circulation around the still deepening low centered across PA and NY. By the afternoon, high pressure will draw closer as it moves into the Lower Mississippi Valley. The story of the day will be chilly temperatures paired with very gusty westerly winds. The tight pressure gradient around the parent low, pressure rises, and diurnal mixing will produce frequent wind gusts to around 30 mph across the entire area, with a few gusts up to around 35 mph possible. Temperatures will struggle into the low 50s in most areas, though locations across interior portions of the counties that border the Midlands might only top out in the upper 40s. With some persist low-level cloud cover and gusty winds, it will certainly feel much colder than what the actual temperature says. Winds will likely fall short of Wind Advisory criteria, but the Lake Wind Advisory for Lake Moultrie will remain in effect through the day. Overnight, the persistent gradient will keep winds elevated through the evening before relaxing late. Clear skies will prevail and lows are forecast to fall into the upper 20s everywhere away from the immediate coast.

Tuesday through Wednesday: The flow aloft will transition from west-northwesterly, to zonal, then southwesterly by late Wednesday. At the surface, high pressure will slide across the area Tuesday, then offshore Wednesday. The forecast is dry, and winds will be considerably weaker. Tuesday highs are forecast for the low to mid 50s, then low 60s by Wednesday. Tuesday night lows should range from around 30 inland, to around 40 at the coast.

Long Term - Wednesday Night Through Sunday
Beginning Wednesday night, a cold front will approach the area from the west and showers could begin spreading in late. The front is expected to shift across the forecast area Thursday and Thursday night and bring at least scattered showers across the entire area. Thursday highs are forecast to reach the low 60s in most areas.

From this point forward, the rest of the extended forecast is a bit of a mess. Both the GFS and ECMWF (European Centre for Medium-Range Weather Forecasts) are displaying wild run to run inconsistencies regarding the potential for a coastal low and possible wintry precipitation for Friday and Friday night. In fact, the 12z runs of both models are now completely dry for the entire region by Friday afternoon. From there the discrepancies continue as the GFS depicts a significant coastal system with widespread precipitation Saturday night and Sunday, while the ECMWF is completely dry and keeps any potential system hundreds of miles further south. Balancing all this in the forecast grids is a challenge to say the least since the NBM still features significant rain chances coincident with periods of below freezing temperatures. Needless to say, forecast confidence in this period of the forecast is as close to zero as it can get.

Marine
Tonight: Dangerous marine conditions will continue through the overnight period as a strong surface low pressure system moves northward away from the forecast area. Gale force winds are expected to prevail through tonight in all waters, including the Charleston Harbor. Seas will remain quite elevated with 9 to 13ft seas forecast.

Monday through Friday: Strong westerly winds will continue across the local waters Monday thanks to a tight pressure gradient around the deepening low pressure centered to the north. Winds will gradually come down through the day, and the ongoing Gale Warnings will need to be replaced with Small Craft Advisories. Winds will drop off to around 5-10 knots Tuesday afternoon and Tuesday night before a modest increase and turning to be out of the south ahead of a front Wednesday night. The cold front will move off the coast Thursday night and high pressure will build in for Friday. This will bring a strong surge of northeast flow and a round of likely Small Craft Advisory conditions.

Tides / Coastal Flooding
Winds will shift to a strong offshore flow tonight, and this will lead to blowout tide conditions around the 1-2 am low tide.

High Surf: Local forecast tools show breakers as large as 5 to 7 feet in the surf zone from late this morning into tonight. This has prompted a High Surf Advisory along coastal sections of Charleston south to coastal Chatham County.

NOAA Charleston SC Office: Watches - Warnings - Advisories
GA...High Surf Advisory until 1am EST Monday for GAZ119. SC...Lake Wind Advisory until 6pm EST Monday for SCZ045. High Surf Advisory until 1am EST Monday for SCZ048-051. High Surf Advisory until 4am EST Monday for SCZ049-050.

Marine
Gale Warning until 1pm EST Monday for AMZ352-374. Gale Warning until 4pm EST Monday for AMZ350. Gale Warning until 10am EST Monday for AMZ354. Gale Warning until 4am EST Monday for AMZ330.