Marine Weather and Tide Forecast for Charleston, SC

KEY MESSAGES
- 1) Dry conditions and below normal temperatures will continue into early next week.

- 2) Strong northeast flow this weekend and into early next week will result in several coastal hazards including tidal flooding, rip currents, high surf, and beach erosion.

DISCUSSION
KEY MESSAGE 1: Dry conditions and below normal temperatures will continue into early next week.

Surface high pressure will extend across the region through late week. Over the weekend, the high will strengthen inland while a coastal trough develops offshore. The air mass will remain quite dry, especially through Friday when LREF indicates PWats fall below the 5th percentile. The pattern will support a rain- free forecast through at least early next week. Despite plenty of sunshine, temperatures will lean on the cooler side of normal. Highs in the upper 60s to lower 70s on Friday will moderate to the lower to mid 70s for the weekend and early next week. Low temperatures will fall into the 40s across many interior locations.

KEY MESSAGE 2: Strong northeast flow this weekend and into early next week will result in several coastal hazards including tidal flooding, rip currents, high surf, and beach erosion.

High pressure will settle across New England and the Mid-Atlantic states Friday into Saturday, favoring an enhanced pressure gradient along the Southeast Coast this weekend and into early next week. The setup will yield strong northeast winds across the area, with the potential for coastal hazards to extend into at least early next week.

Coastal Flooding: Astronomical tides will continue to rise through the weekend and into next week with the upcoming lunar perigee (10/28) and full moon (10/26). In fact, the highest astronomical tides for all of 2026 will come Tuesday (10/27) and Wednesday (10/28) when Charleston Harbor peaks at ~6.9 ft MLLW and Fort Pulaski peaks at 8.9 ft MLLW. With another period of strong northeast flow on the way this weekend, large tidal departures will start to overlap with increasing astronomical tides, providing increased probabilities of seeing a multi-day coastal flooding event for the entire coast. Minor coastal flooding could begin as early as the upcoming late afternoon high tide cycle, and this minor flooding potential will continue through the rest of the week. Over the weekend and into next week, the potential for moderate to even major coastal flooding will increase at the Charleston Harbor. At Fort Pulaski, minor to moderate coastal flooding will be possible during this time period. Of note, the morning high tide cycle will be the dominant high tide of the day.

Coastal Hazards: Strong northeast winds and increased wave action will support an elevated rip current risk over the weekend and into early next week. A Moderate Risk for rip currents is in place for all beaches Saturday, followed by a High Risk Saturday. An enhanced period of rip currents will likely continue into early next week.
Also, high surf with breaking wave heights of 5 ft or higher will be possible and High Surf Advisories could be needed this weekend into early next week. The combination of elevated tides, increased wave action, and persistent gusty northeast winds will likely produce beach erosion, with the most significant erosion occurring around high tide cycles this weekend.

Lake Winds: Gusty northeast winds are expected to develop on Lake Moultrie Friday night and continue through the weekend. A Lake Wind Advisory could be needed for winds gusting up to 25 kt and waves of 2-3 ft. The combination of steady northeast winds and wave action could yield some lakeshore erosion along the southwest side of the lake along with some overwash. This is includes areas from roughly Pinopolis to Blacks Camp near Cross.

AVIATION /18Z THURSDAY THROUGH TUESDAY/
KCHS/KJZI/KSAV: VFR through 23/18z.

Extended Aviation Outlook: Breezy northerly winds anticipated at CHS/JZI/SAV terminals Saturday and Sunday. Otherwise, VFR conditions are expected at all terminals this weekend into early next week.

MARINE
Through Tonight: North to northeast winds will persist through tonight. Speeds will generally be 15 knots or less, but will start to creep up to the 15-20 kt range closer to daybreak Friday. Seas will average 2-3 ft across the nearshore waters, 3-5 ft over the South Carolina offshore waters and 3-6 ft over the Georgia offshore waters where a Small Craft Advisory remains in effect.

Friday through Monday: High pressure will strengthen across the Mid- Atlantic states while low pressure develops north of the Bahamas this weekend. The setup will favor a strong pressure gradient across local waters with marine conditions rapidly deteriorating Friday night. Winds/seas will substantially increase during the weekend, likely reaching Small Craft Advisory level conditions for a period Friday evening, before gales are prevalent by daybreak Saturday across most waters outside the Charleston Harbor, then peak in intensity Sunday, before slowly improving Monday and Tuesday. Strong gales are possible during the weekend, especially for the 20-60 nm waters.

A Small Craft Advisory remains in effect across offshore GA waters through the weekend into early next, but will likely need to be upgraded to a Gale Watch/Warning for the weekend into early next week. A short duration Small Craft Advisory could also become necessary across nearshore waters Friday night prior to Gale Watch/Warning issuances this weekend. A Small Craft Advisory will likely be needed across the Charleston Harbor this weekend. Winds and seas start to trend lower late Monday, but Small Craft Advisory level conditions could persist across local waters outside the Charleston Harbor through early Wednesday.

CHS WATCHES/WARNINGS/ADVISORIES
GA...None.
SC...None.
MARINE...Small Craft Advisory until 6 AM EDT Tuesday for AMZ384.