Marine Weather Net

Charleston Harbor Marine Forecast


TONIGHT

S
WINDS
10 - 15
KNOTS

FRI

S
WINDS
5 - 10
KNOTS

FRI NIGHT

S
WINDS
5 - 10
KNOTS

SAT

S
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
AMZ330 Forecast Issued: 342 PM EDT Thu Aug 06 2020

Tonight...S Winds 10 To 15 Kt, Diminishing To 5 To 10 Kt After Midnight. A Chance Of Showers And Tstms, Mainly This Evening.
Fri...S Winds 5 To 10 Kt. A Chance Of Showers And Tstms.
Fri Night...S Winds 5 To 10 Kt. A Chance Of Showers And Tstms.
Sat...S Winds 5 To 10 Kt. A Chance Of Showers And Tstms.
Sat Night...S Winds 5 To 10 Kt. A Chance Of Showers And Tstms.
Sun...S Winds 5 To 10 Kt. A Chance Of Showers And Tstms.
Sun Night...Sw Winds 5 To 10 Kt. A Chance Of Showers And Tstms.
Mon...Sw Winds 5 To 10 Kt. A Chance Of Showers And Tstms.
Mon Night...S Winds 5 Kt. A Chance Of Showers And Tstms.
Tue...Sw Winds 5 To 10 Kt. A Chance Of Showers And Tstms.
Tue Night...S Winds 5 Kt. A Chance Of Showers And Tstms. Mariners Are Reminded That Winds And Waves Higher In And Near Tstms. Unless Otherwise Noted, Waves 1 Foot Or Less. Charleston Harbor Water Temperature 85 Degrees.
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Area Forecast Discussion
National Weather Service Charleston SC
356pm EDT Thu August 6 2020

Synopsis
A weak stationary front will linger in the vicinity through the weekend, dissipating by early next week. Thereafter, the region will remain situated between Atlantic high pressure and an inland trough of low pressure.

Near Term - Until 6am Friday Morning
The area will remain under a stationary front and between an upper- level trough and surface Atlantic high pressure tonight. Through early afternoon, showers/thunderstorms have generally remained in the SC Lowcountry along the sea breeze. As we reached peak heating, radar imagery showed that multiple outflow boundaries have formed across the area as well as cumulus/towering cumulus. Coverage is expected to increase across SE GA through this evening as activity moves in from the southwest. Most of the guidance has any showers/thunderstorms diminishing this evening after the loss of daytime heating. Overnight, maintained slight chance POPs as a weak shortwave trough approaches the area from the west. Low temperatures are expected to be mid to high 70s.

Short Term - 6am Friday Morning Through Sunday
Friday through Sunday: Aloft, the forecast area will sit on the eastern periphery of a weak trough, along the border of the Atlantic ridge. At the surface, a nearly stationary boundary will meander around Georgia and the Carolinas. Overall, a fairly common looking summertime pattern, with perhaps a bit more convective coverage thanks to the presence of the trough and the boundary. At least scattered coverage of thunderstorms is expected each day, with time periods where different areas will need locally higher rain chances. Models also hint at nocturnal thunderstorm activity, primarily for the coastal waters, but could impact coastal areas each night. It's hard to call the severe threat particularly significant, but with boundary interactions we will likely see a couple of strong to marginally severe storms each day. Storm motion will likely be slow and precipitable water values will be over 2 inches, especially Friday. Locally heavy rainfall will be possible. Look for highs in the low to mid 90s. Lows should range in the low to mid 70s away from the coast and upper 70s to low 80s at the beaches.

Long Term - Sunday Night Through Thursday
A typical mid-summer pattern will prevail, featuring at least normal coverage of diurnal thunderstorms and typically hot/humid conditions. The stationary front will dissipate early week and will give way to an inland trough of low pressure. Also, the upper trough over the eastern Conus is forecast to weaken/shift west, and the Atlantic Ridge should build/expand over the region. This could translate to somewhat diminished coverage of diurnal precipitation, as compared with the relatively active period through this weekend. However, given the persistence of PWAT (Precipitable Water) values over 2 inches, scattered thunderstorms should continue to readily develop along the sea breeze/outflow boundaries each day.

Marine
Marine: Southerly winds will remain 10-15 knots with occasional higher gusts during coastal convection.

Friday through Tuesday: Atlantic high pressure will drive a prevailing south to southwest flow through early next week. Winds will peak each afternoon and evening with the diurnal sea breeze and with modest nocturnal surging. Speeds should top out around 15 knots through the period. Seas will average 2-3 feet.

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