Debby updates: Flash flooding, tornadoes target DC, Mid-Atlantic, Northeast

Debby has sustained winds of 60 mph as it drifts roughly 85 miles off the coast of Myrtle Beach, South Carolina, moving at 3 mph.

The tropical storm is expected to make landfall again late Wednesday into early Thursday morning near Myrtle Beach.

The storm is expected to bring significant to catastrophic flooding, with flood watches and warnings covering much of the Carolinas. The high risk for excessive rainfall stretches from North Carolina into southern Virginia on Thursday.

A tornado watch is also in effect until 11 p.m. ET Wednesday for eastern North and South Carolina, where spin-up tornadoes are possible.

-ABC News' Daniel Amarante

Tropical Storm Debby -- currently sitting off shore of Charleston, South Carolina -- is forecast to make a second landfall Wednesday night between Charleston and Myrtle Beach, South Carolina.

Another 6 inches of rain is possible for the Carolinas over the next 24 hours before Debby exits the region. A rare “high risk” for flash flooding is ongoing for the Carolinas, including the cities of Myrtle Beach, Wilmington and Raleigh.

By Thursday afternoon, Debby will begin to move north. By Friday, the storm will bring heavy rain and potentially flooding to Virginia, and then will reach the Northeast and New England.

-ABC News' Melissa Griffin

A city-wide curfew was lifted Wednesday morning in flood-prone Charleston, South Carolina.

No rescues were needed due to the curfew, Mayor William Cogswell said.

"After assessing overnight conditions, officials have determined that it is safe to return to normal activities," the mayor said in a statement, but he added that the ongoing storm may still lead to downed trees and power lines.

"Several roads remain closed and are barricaded," the mayor said. "Please avoid driving around barricades or entering flood waters."

Tropical Storm Debby -- currently sitting off shore of Myrtle Beach, South Carolina -- is forecast to make a second landfall late Wednesday into early Thursday near Myrtle Beach, bringing more heavy rain.

The storm is bringing significant to catastrophic flooding to portions of the Southeast, with flood watches and warnings covering much of the Carolinas. Rain totals could reach 20 to 25 inches in South Carolina and 15 inches in North Carolina.

A "high risk" for excessive flooding has been issued from North Carolina into southern Virginia for Thursday. Click here to read more.