Charleston Harbor Marine Forecast
|Tonight...S Winds 5 Kt, Becoming E. Patchy Fog After Midnight.|
|Mon...E Winds 5 To 10 Kt, Increasing To 10 To 15 Kt With Gusts To 20 Kt In The Afternoon. A Chance Of Showers With A Slight Chance Of Tstms In The Morning, Then A Chance Of Showers And Tstms In The Afternoon.|
|Mon Night...E Winds 10 To 15 Kt. A Chance Of Showers After Midnight.|
|Tue...E Winds 10 To 15 Kt With Gusts To 25 Kt. A Chance Of Showers In The Morning, Then Showers Likely With A Chance Of Tstms In The Afternoon.|
|Tue Night...E Winds 15 Kt, Diminishing To 10 Kt After Midnight. Showers Likely With A Chance Of Tstms.|
|Wed...E Winds 10 Kt. Showers And Tstms Likely.|
|Wed Night...Se Winds 5 To 10 Kt. Showers And Tstms Likely In The Evening, Then A Chance Of Showers With A Slight Chance Of Tstms After Midnight.|
|Thu...Se Winds 5 To 10 Kt. A Chance Of Showers And Tstms.|
|Thu Night...Se Winds 5 To 10 Kt. A Chance Of Showers And Tstms.|
|Fri...Se Winds 5 To 10 Kt. A Chance Of Showers And Tstms.|
|Fri Night...S Winds 5 To 10 Kt. A Slight 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 79 Degrees.|
Area Forecast Discussion|
National Weather Service Charleston SC
853pm EDT Sunday May 24 2020
A weak cold front will push into the area later tonight and Monday, and high pressure will build over the region from the north. A coastal trough should develop around mid week, and low pressure could track over or near the Southeast coast mid to late week. A cold front could approach the region next weekend.
Near Term - Until 6am Monday Morning
One last convective cluster will work west across northern Jenkins County over the next hours, then dry weather will prevail. Adjusted probability of precipitation based on short term radar trends.
Expect low stratus and possible some fog to fill in along/ahead of the backdoor front early Monday. The fog is not expected to have much impact, but some areas of reduced visibilities could occur. Dense fog is not expected at this time.
Warm and humid conditions will persist with lows ranging from the upper 60s/near 70 inland, lower 70s at the coast, with mid 70s at the beaches and Downtown Charleston.
Short Term - 6am Monday Morning Through Wednesday
Monday: High pressure will build into the region from the north and will push a weakening cold front toward the south. At least scattered showers and thunderstorms could develop near this boundary, with higher Probability of Precipitation across northern counties during the morning followed by high Probability of Precipitation shifting into southern/western sections during the afternoon. Forecast instability suggests only a low chance for a brief/isolated pulse severe thunderstorm or two.
Monday night: Due to diurnal stabilization, isolated/scattered showers and perhaps isolated thunderstorms near the stalling cold front across southern/western counties should diminish in coverage through at least the first half of the night. Then, guidance depicts a band of deeper moisture to spreading from the south in at least southern counties later on.
Tuesday and Wednesday: Guidance indicates a wet period as a pool of PWAT (Precipitable Water) values around 2 inches settles over the region. However, timing/coverage of showers/thunderstorms will be linked with strength of the surface high N/NE of the region and to the uncertain evolution of a surface trough/surface low S/SE of the area. The latest forecast ramps Probability of Precipitation up to likely all but far northern/inland counties Tuesday. Then, Probability of Precipitation vary from likely along the SC coast to chance elsewhere Tuesday night. Wednesday, Probability of Precipitation range from likely north to chance south. However, forecast confidence decreases Tuesday night and remains rather low through Wednesday.
The potential for locally heavy rain will increase Tuesday through Wednesday, especially near the coast where tides will be elevated due to persistent E/NE flow. If stronger low pressure tracks over or inland from the coast Tuesday night through Wednesday, the potential for severe weather could increase.
Also of note, greater than expected coverage/persistence of clouds/precipitation could translate to cooler daytime temperatures than indicated within the latest forecasts.
Long Term - Wednesday Night Through Sunday
The start of this period remains uncertain and will depend on whether surface low pressure remains in the vicinity into Thursday. Otherwise, on the western periphery of Atlantic surface high pressure/beneath a weak ridge of high pressure aloft, a surface trough should linger over the region with above normal precipitation and temps into this weekend. A cold front could approach or move into the area by late next weekend.
Tonight: South to southeast winds will gradually back as a weak cold front approaches. Speeds will remain <10kt with seas 1-2 ft nearshore waters and 2-3 ft offshore waters.
Monday through Friday: On Monday, as a high pressure system builds over the area throughout the day, winds will increase as the pressure gradient tightens. Then, as a low pressure system lingers off the east coast of Florida, the pressure gradient will tighten more, causing winds and seas to gradually increase. Small Craft Advisories will likely be needed starting Tuesday afternoon into at least Wednesday morning. While there is still some uncertainty about the track of the low over or close to the Southeast coast mid to late week. Some guidance suggests that the pressure gradient starts to relax mid to late week, but the low pressure could maintain elevated winds and seas through Friday.
Tides / Coastal Flooding
Persistent E/NE flow will support elevated tides this week. Mid to late week, there exists a low probability for minor salt water flooding around the times of the overnight high tides. Also, we'll continue to assess the potential for heavy rainfall to coincide with high tides at the coast, especially during the Tuesday-Thursday period.
NOAA Charleston SC Office: Watches - Warnings - Advisories
GA...None. SC...None. MARINE...None.