Marine Weather Net

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


REST OF TODAY

SE
WINDS
15 - 20
KNOTS

TONIGHT

S
WINDS
15 - 20
KNOTS

TUE

SW
WINDS
10 - 15
KNOTS

TUE NIGHT

SW
WINDS
10
KNOTS

The Marine Weather Forecast In Detail:
AMZ354 Forecast Issued: 1029 AM EDT Mon May 12 2025

SMALL CRAFT ADVISORY IN EFFECT FROM 2 PM EDT THIS AFTERNOON THROUGH LATE TONIGHT
Rest Of Today...Se Winds 15 To 20 Kt With Gusts To 25 Kt. Seas 4 To 5 Ft, Building To 4 To 6 Ft This Afternoon. Wave Detail: Se 5 Ft At 7 Seconds. A Chance Of Tstms. Showers.
Tonight...S Winds 15 To 20 Kt, Diminishing To 10 To 15 Kt After Midnight. Seas 4 To 6 Ft, Subsiding To 4 To 5 Ft After Midnight. Wave Detail: Se 6 Ft At 7 Seconds, Becoming Se 5 Ft At 7 Seconds. A Chance Of Tstms. Showers, Mainly In The Evening.
Tue...Sw Winds 10 To 15 Kt. Seas 4 To 5 Ft. Wave Detail: Se 5 Ft At 8 Seconds. A Chance Of Showers. A Chance Of Tstms, Mainly In The Morning.
Tue Night...Sw Winds 10 Kt. Seas 3 To 4 Ft. Wave Detail: Se 4 Ft At 8 Seconds. A Chance Of Showers. A Chance Of Tstms, Mainly In The Evening.
Wed...Sw Winds 10 Kt, Becoming S In The Afternoon. Seas 2 To 3 Ft. Wave Detail: Se 3 Ft At 8 Seconds And S 1 Foot At 4 Seconds. A Slight Chance Of Showers In The Morning, Then A Chance Of Showers And Tstms In The Afternoon.
Wed Night...S Winds 10 Kt. Seas 2 To 3 Ft. Wave Detail: Se 3 Ft At 8 Seconds And S 2 Ft At 4 Seconds. A Chance Of Showers And Tstms In The Evening, Then A Slight Chance Of Showers After Midnight.
Thu...Sw Winds 10 Kt. Seas 2 To 3 Ft.
Thu Night...Sw Winds 10 Kt. Seas 2 To 3 Ft.
Fri...Sw Winds 10 Kt. Seas 2 To 3 Ft.
Fri Night...Sw Winds 10 Kt. Seas 2 To 3 Ft. Winds And Seas Higher In And Near Tstms.
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Area Forecast Discussion
National Weather Service Charleston SC
Issued by National Weather Service Columbia SC 229pm EDT Monday May 12 2025

Synopsis
A front will remain stalled near the area, before lifting north of the region by midweek. High pressure is expected to return late week.

Near Term - Through Tonight
Radar has remained active through the morning, with the main band of precipitation now oriented more over southeast South Carolina. This should continue to lift northward through the remainder of the morning.

This afternoon, convection should become more cellular and storm motions around 25 mph. Moderate to heavy downpours are possible with these storms, given deep warm cloud depth and PW values (Precipitable Water values) around 1.9 inches. Categorical Probability of Precipitation this morning will transition to likely Probability of Precipitation this afternoon. The CWA (County Warning Area) will remain in the warm sector between a lifting warm front and approaching cold front this afternoon. High temperatures are forecast to range in the mid to upper 70s.

This evening, the cold front is timed to push over SE GA this evening, then over the SC Lowcountry late tonight. This boundary should focus the development of thunderstorms, possibly developing into a band of storms. These storms will push NE across the CWA this evening and tonight. The storms may remain strong to severe across SE GA this evening given lingering instability and shear, with damaging wind gusts the primary hazard. Storm Prediction Center has highlighted the region with a marginal risk for severe weather. Low temperature are forecast to range in the mid to upper 60s.

Short Term - Tuesday
The closed low in the mid-levels will begin to open up and progress northeastward towards the Mid-Atlantic states on Tuesday and into Wednesday. By Thursday the mid-level trough will eject off the Mid- Atlantic coast with ridging beginning to build into the southeastern states. At the surface a cold front will push off the southeastern coast on Tuesday, with high pressure building in on Wednesday and into Thursday. The wet pattern across the region will shift drier as the front exits the region and high pressure begins to dominate the synoptic pattern. Scattered to widespread showers and thunderstorms will be possible Tuesday and Wednesday afternoon, mainly diurnally driven with some lingering forcing from the departing front.

Temperatures Tuesday and Wednesday will generally be in the low to mid 80s, with overnight lows in the 60s to around 70 at the beaches. As high pressure builds into the region both aloft and at the surface temperatures on Thursday will rise into the upper 80s to around 90 in some locations.

Long Term - Tuesday Night Through Monday
The main forecast highlight for the long term period is the hot temperatures. With ridging building in aloft and high pressure at the surface temperatures will soar above normal, with highs forecast in the low to even mid 90s across the region. These temperatures combined with dew points forecast in the upper 60s to low 70s could yield heat index values of 100-103F at the end of the week. While below advisory criteria, this could be the real first blast of heat across the region.

Marine
Thunderstorms will remain common across the marine zones today and tonight, the greatest coverage this morning with another band of storms this evening. Some of these storms could produce wind gusts of 34 kts or greater, a waterspout cannot be ruled out this morning. The pattern will support southeast winds between 10 to 15 kts with gusts around 25 kts across the Atlantic waters. Seas will build to 4 to 7 ft by this afternoon, then slowly decreasing after midnight tonight. Small Craft Advisories have been posted to highlight the wind and wave conditions for today into tonight.

Tuesday through Saturday: A front will push offshore into the adjacent Atlantic waters on Tuesday with high pressure building in thereafter and into the weekend. Some 6 ft seas will likely be lingering in the Charleston County nearshore waters and the 20 to 60 nm offshore GA waters through around noontime on Tuesday. A Small Craft Advisory will remain in effect for those waters. Through the remainder of the week generally quiet marine conditions are forecast, with winds around 15 knots. Higher gusts are possible along the coastline and in the Charleston Harbor each afternoon with the sea breeze. Seas will decrease to 2 to 3 ft into the weekend.

Rip Currents, the combination of onshore flow and 2 to 3 breakers may produce rip currents along the SC/GA coast today. Breakers could exceed 3 ft along the Charleston County coast this afternoon.

NOAA Charleston SC Office: Watches - Warnings - Advisories
GA...None. SC...None.

Marine
Small Craft Advisory until 8pm EDT this evening for AMZ330. Small Craft Advisory until 2pm EDT Tuesday for AMZ350-374. Small Craft Advisory until 8am EDT Tuesday for AMZ352. Small Craft Advisory until 2am EDT Tuesday for AMZ354.