Charleston Harbor Marine Forecast
|Tonight...Ne Winds 5 Kt Until Early Morning, Becoming Light And Variable. Patchy Fog Late.|
|Tue...E Winds 5 Kt.|
|Tue Night...Se Winds 5 Kt In The Evening, Becoming Light And Variable.|
|Wed...Nw Winds 5 Kt, Becoming Se In The Afternoon.|
|Wed Night...Se Winds 5 Kt.|
|Thu...S Winds 5 To 10 Kt, Increasing To 15 Kt In The Afternoon.|
|Thu Night...S Winds 10 To 15 Kt With Gusts To 25 Kt. A Chance Of Showers.|
|Fri...Sw Winds 15 To 20 Kt. Waves 1 To 2 Ft. Showers Likely With A Slight Chance Of Tstms.|
|Fri Night...W Winds 15 To 20 Kt. Waves 1 To 2 Ft. A Chance Of Showers With A Slight Chance Of Tstms.|
|Sat...W Winds 15 To 20 Kt. Waves 1 To 2 Ft. A Slight Chance Of Showers.|
|Sat Night...Nw Winds 15 To 20 Kt. Waves 1 To 2 Ft. Winds And Waves Higher In And Near Tstms. Unless Otherwise Noted, Waves 1 Foot Or Less. Charleston Harbor Water Temperature 56 Degrees.|
| Area Forecast Discussion|
National Weather Service Charleston SC
949pm EST Monday Feb 6 2023
High pressure will prevail through Wednesday. A series of cold fronts will affect the area late Thursday through Saturday morning, followed by dry high pressure.
Near Term - Until 6am Tuesday Morning
Conditions across the forecast area through the rest of this evening will remain clear with light to calm surface winds. IR satellite images show thin cirrus across GA/AL, drifting east. Cirrus is expected to gradually increase across the CWA after midnight. Recent round of observations indicated that dewpoints along the coast ranged between 45-50 degrees. Latest guidance indicates that the dewpoints are expected to remain in the 40s through daybreak Tuesday. Patchy fog is forecast to develop within the pool of warmer dewpoints along the GA and SC coast during the pre-dawn hours, generally south of the CHS Harbor.
The forecast will indicate low temperatures from the mid 30s inland, ranging to the upper 30s and low 40s as you get closer to the coast. We could even see a few locations dip into the low 30s in the usual cool spots, including the Francis Marion National Forest.
Short Term - 6am Tuesday Morning Through Thursday
A deep layered ridge centered over the southern Florida Peninsula will extend into the Southeast U.S. Tuesday through Thursday morning, which will then begin to shift east further into the Atlantic as an upper trough approaches. The forecast will stay dry and rain-free through Wednesday night with mostly clear skies increasing Wednesday as some mi-level moisture begins to fill in. A weak upper shortwave will move into the area Thursday, accompanied by an increase in low-level moisture. A few showers could move in from the west Thursday late afternoon gradually spreading eastward toward the coast in the evening. A steady warming trend is expected thanks to low-level southerly flow, with highs in the upper 60s to low 70s Tuesday increasing to the low to upper 70s on Thursday. Low temps will increase to above normal Tuesday night, in the mid to upper 40s most places and low 50s across the coast. Wednesday night, lows will only drop down into the low to mid 50s.
Long Term - Thursday Night Through Monday
A series of shortwaves, followed by the arrival of a longwave trough and an approaching cold front will bring scattered/numerous showers and a few thunderstorms to the area Thursday night through Friday night. Precipitation will continue to spread eastward Thursday night into Friday, with the bulk of the rainfall occurring Friday. Moisture and precipitation are expected to move off the coast by Saturday morning, as cool, dry high pressure builds in. Friday will start off mild with highs around 70 degrees, becoming much cooler over the weekend in the wake of the cold front. Thursday nights' lows will also be warm with temperatures some 20 degrees above normal; in the low 60s. Thereafter, low temps will rapidly drop to just below or near normal.
Tonight: The pressure gradient will weaken significantly this evening and wind speeds will diminish to 10 knots or less out of the northeast through the overnight. Seas should average 2-3 feet.
Tuesday through Saturday: Light and variable winds with predominantly southerly flow will develop Tuesday and continue through late week as high pressure builds over the western Atlantic. Winds/seas will becomes elevated Thursday, but are expected to remain below advisory levels through Thursday night. Some models hint at sea fog developing Thursday, but increasing wind speeds could be a large limiting factor. Strengthening southerly flow ahead of a cold front Friday is expected to result in 6-7 ft seas moving into the Charleston County nearshore waters and the outer Georgia waters from 20-60 nm. In addition, gusts 25-30 kt will spread across the local waters Friday morning. Small Craft Advisories could be needed for most of the marine zones starting as early as Friday morning, continuing into Saturday.
NOAA Charleston SC Office: Watches - Warnings - Advisories