Charleston Harbor Marine Forecast
5 - 10
5 - 10
10 - 15
10 - 15
5 - 10
10 - 15
|Tonight...E Winds 5 To 10 Kt, Becoming Ne Late This Evening.|
|Wed...Ne Winds 5 To 10 Kt, Becoming E 10 To 15 Kt With Gusts To 20 Kt In The Afternoon.|
|Wed Night...E Winds 10 To 15 Kt, Becoming Ne 5 To 10 Kt After Midnight.|
|Thu...Ne Winds 10 To 15 Kt.|
|Thu Night...Ne Winds 5 To 10 Kt.|
|Fri...Ne Winds 10 To 15 Kt With Gusts To 20 Kt. A Slight Chance Of Showers And Tstms In The Afternoon.|
|Fri Night...Ne Winds 10 To 15 Kt With Gusts To 20 Kt. A Slight Chance Of Showers And Tstms.|
|Sat...Ne Winds 10 To 15 Kt. A Chance Of Showers And Tstms.|
|Sat Night...Ne Winds 15 Kt. A Chance Of Showers And Tstms.|
|Sun...Ne Winds 15 To 20 Kt. Waves 1 To 2 Ft. A Chance Of Showers And Tstms.|
|Sun Night...Ne Winds 15 To 20 Kt. Waves 1 To 2 Ft. A Chance Of Showers And Tstms. Winds And Waves Higher In And Near Tstms. Unless Otherwise Noted, Waves 1 Foot Or Less. Charleston Harbor Water Temperature 72 Degrees.|
| Area Forecast Discussion|
National Weather Service Charleston SC
727pm EDT Tuesday May 30 2023
High pressure will expand across the area from the north through the weekend while weak low pressure remains off the coast.
Near Term - Until 6am Wednesday Morning
The sea breeze will clear the entire forecast counties early this evening, and with minimal MLCAPE, poor mid level lapse rates and insignificant Normalized CAPE, we look for what little activity there is to come to an end by 9 pm or so. We removed thunder from the forecast based on this same reasoning. Guidance is even less aggressive on fog potential late tonight compared to the past two nights, so no need to include any mention with the latest forecast. Instead there will be some low stratus behind a very weak back door front late tonight, which looks to make it through the northern portion of the local counties well after midnight. No changes to the min temp forecast.
Previous discussion... At 330 PM: KCLX detected a wavy sea breeze advancing inland across SE GA and SC. So far this afternoon, isolated to scattered showers have develop along and near the sea breeze across the forecast area. An isolated thunderstorm was observed earlier across Bryan and Bulloch Counties. Storm Prediction Center mesoanalysis indicates that SBCAPE may increase slightly by late afternoon. The forecast will continue to indicate isolated to scattered showers with isolated thunderstorms, greatest coverage inland. By early this evening, CAPE should diminish with values of CIN expanding in the wake of the sea breeze and cooling temperatures around sunset. Any remaining showers and thunderstorms should either dissipate or push inland of the forecast area during the early evening hours.
Tonight, the surface pattern will feature a weak low over southern GA with a building ridge across the western Carolinas. Near term guidance indicates that the lead edge of the surface ridge or CAD will approach or arrive over the northern portion of the CWA (County Warning Area) by daybreak Wednesday. The CAD should slightly strengthening NE winds and increased cloud cover. Conditions should remain free of showers and drizzle. Low temperatures are forecast to range from the low to mid 60s inland to the mid to upper 60s along the coast.
Short Term - 6am Wednesday Morning Through Friday
A weak upper low over the central Gulf of Mexico will remain in place through Wednesday. At the surface, broad high pressure off the New England coast will continue to wedge down the Eastern Seaboard, yielding NE to E surface winds. A weak backdoor front is expected to drop through the area Wednesday morning, stalling along the southern edge of the forecast area. Slightly deeper moisture will reside over inland southeast GA on Wednesday which coincides with occasional vorticity maxima rotating around the Gulf of Mexico upper low. Thus, the best chance for diurnal convection will be across southeast GA inland from the coast.
Relatively little convection is expected on Thursday due to some drier air moving in from the north and a relative lack of forcing for ascent. Isolated afternoon convection is possible on Friday due to slightly higher PWATs (Precipitable Waters) and a decent afternoon sea breeze.
Temperatures will be slightly below normal with highs in the lower 80s and lows in the mid 60s.
Long Term - Friday Night Through Tuesday
A broad upper level trough pattern will remain in place over the Southeast Saturday through Monday, then a zonal flow will develop Tuesday. Surface high pressure will continue to wedge down the Eastern Seaboard through the period, with a reinforcing cold front possible Saturday night. A surface low could develop over central FL this weekend, then shift NE early next week. Mainly diurnal convection expected each day. Highs will be a few degrees below normal through Monday, then near normal on Tuesday.
A broad inverted trough will remain across the marine zones this evening. The leading edge of a surface ridge will advance from north to south across the marine zones tonight. East winds are forecast to range between 5 to 10 kts this evening, backing to northeast late tonight and increasing to around 10 kts. Wave heigheights are forecast to range between 2-3 ft.
Persistent NE flow expected Wednesday through Monday as high pressure continues to build down from the north. The gradient will tighten a bit late Saturday, with 20-25 kt winds and 4-6 ft seas possible Sunday into Monday. Small Craft Advisories will likely be needed eventually.
NOAA Charleston SC Office: Watches - Warnings - Advisories