Tropical Storm Andrea formed Wednesday in the Gulf of Mexico and was forecast to skirt the Lowcountry coast. A tropical storm watch is in effect.

Today into Friday, there’s the potential for heavy rain and flooding and a chance of thunderstorms, according to meteorologists at the National Weather Service, Charleston. An isolated tornado can’t be ruled out. Winds will be gusting, possibly up to 40 mph by Friday, and the risk of rip currents will be high.

The weather is expected to improve into Saturday, but scattered afternoon showers and thunder showers will be possible throughout the weekend.

This week already has offered periods of inclement weather.

Two tornadoes raked Dorchester County during Tuesday’s thunderstorms, the Weather Service confirmed Wednesday. The Gulf storm is expected to exacerbate that stormy weather.

The Charleston area already has seen well-above-average rainfall for the year, so the ground is soaked. Weather conditions that have fed recent thunderstorms are expected to persist.

One of the tornadoes Tuesday formed in Orangeburg County near Duncan Chapel Road with 100-mph-plus winds. It traveled some 2 miles into Dorchester County near U.S. Highway 15. The second formed just to the southeast of the first storm, traveled across Interstate 95 and lifted near Quail Run Road.

A tree fell through a mobile home and a roof was damaged on another home. Other damage was mainly to trees and crops in the field, said senior meteorologist Steve Taylor, with the Weather Service. “It obliterated crops up there,” he said.

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