Savannah, GA to Altamaha Sound, GA including Grays Reef National Marine Sanctuary Marine Forecast
|Today...Nw Winds 10 To 15 Kt With Gusts To 20 Kt. Seas 3 To 4 Ft.|
|Tonight...N Winds 10 Kt. Seas 3 Ft.|
|Fri...Ne Winds 10 To 15 Kt. Seas 2 To 3 Ft.|
|Fri Night...Ne Winds 5 To 10 Kt. Seas 2 To 3 Ft.|
|Sat...N Winds 5 To 10 Kt. Seas 2 To 3 Ft.|
|Sat Night...N Winds 5 Kt, Becoming Nw After Midnight. Seas 2 Ft.|
|Sun...N Winds 5 To 10 Kt. Seas 2 Ft.|
|Sun Night...Sw Winds 5 Kt. Seas 2 Ft.|
|Mon...N Winds 5 Kt. Seas 2 Ft.|
|Mon Night...S Winds 5 To 10 Kt. Seas 2 Ft.|
| Area Forecast Discussion|
National Weather Service Charleston SC
714am EDT Thu September 23 2021
High pressure will build across the region today, then prevail this weekend through the middle of next week.
Near Term - Through Tonight
Latest water vapor showed a well developed area of low pressure lifting north over the Great Lakes region. South of the low, deep dry air was pushing east across the Southeast U.S. in the wake of a cold front. A few thin patches of high clouds may remain over the nearshore waters during the early daylight hours, then sunny conditions expected for the rest of the day. Near term models indicate that weak Cold Air Advection will occur at H85 through mid-day. Stronger Cold Air Advection is expected this afternoon across the CWA. In fact, the 6Z GFS indicates that H85 temperatures over Lake Moultrie will cool from near 15C at 18Z to 11.5C by 0Z. Temperatures are forecast to peak early this afternoon in the upper 70s to around 80, remaining nearly steady through mid- afternoon. Temperatures should cool off steadily this evening, with 60s inland by sunset. The center of surface high pressure is expected to build over the southern Appalachians by late tonight, spreading across the CWA. The combination of a clear sky and light north winds will yield steadily cooling temperatures tonight. Using a blend of MOS, low temperatures are forecast to range from the low 50s inland to around 60 degrees along the coast.
Short Term - Friday Through Sunday
High pressure will spread across the region this weekend along the southern edge of a broad mid-level trough extending across the Midwest and Northeast regions. Given the pattern, considerably drier and slightly cooler conditions are expected across the Southeast United States to start off the weekend. Despite sunny conditions, a northerly wind will keep highs around 5 degrees below normal initially on Friday, generally in the upper 70s-lower 80s. Friday night lows should also remain considerably cooler than normal with a favorable radiational cooling in place. In general, many locations will dip into the low-mid 50s inland to low-mid 60s at the beaches. A gradual warming trend is then anticipated as a light northwest wind develops along the southern edge of the surface high on Saturday, followed by a more favorable downsloping wind setup across the region heading into Sunday. In general, highs should range in the lower 80s Saturday afternoon, then low-mid 80s Sunday afternoon. Low temps will be a few degrees warmer as well, but still averaging in the mid-upper 50s inland to mid 60s near the beaches.
Long Term - Sunday Night Through Wednesday
An extended period of quiet weather is expected through the middle of next week as a large area of high pressure remains centered across the Mid-Atlantic and Southeast regions. Dry conditions are expected for the next several days, but temps should gradually warm through the period under mostly sunny skies and a downslope wind component across the region early week, followed by mid-level ridging by the middle of the week. In general, highs will range in the mid/upper 80s each day, warmest across southeast Georgia away from the coast. Lows should initially range in the upper 50s inland to mid-upper 60s near the coast Sunday night, then gradually warm to the low-mid 60s inland to upper 60s/lower 70s as light surface winds turn onshore midweek.
High pressure will build over the marine zones today through tonight. Surface winds are forecast to remain from the northwest today, gusts to around 20 kts this morning. Winds will veer from the northeast tonight, speeds ranging between 10 to 15 kts. Seas this morning should range between 3 to 5 ft, settling to 3 to 4 ft this afternoon through tonight.
Friday through Tuesday: High pressure will spread across region this weekend and prevail through early next week. The pattern will result in quiet weather conditions across local waters with winds/seas remaining well below small craft advisory levels. In general, north- northeast winds peaking around 15 kt Friday will weaken and turn more west-northwest Saturday into Sunday as surface high pressure becomes centered just inland and north of the area. Light onshore winds should then develop as the center of the high begins to shift off the Mid-Atlantic Coast. Seas will average between 2-4 ft to start off the weekend, then gradually subside to 1-3 ft late weekend and persist through early next week.
NOAA Charleston SC Office: Watches - Warnings - Advisories