Tropical Storm Debby tracker, maps: Latest storm path

Tropical Storm Debby is threatening the Carolinas with major flooding and a second landfall as the slow-moving storm crawls north.

Here's what to expect:

Tropical Storm Debby -- currently sitting off shore of Myrtle Beach, South Carolina -- is forecast to make a second landfall late Wednesday night into Thursday morning 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.

The storm is expected to drench the Carolinas and Mid-Atlantic on Thursday before moving up the East Coast and into the Northeast.

Four to six inches of rain and flash flooding are possible in the Mid-Atlantic.

On Friday morning, the remnants of Debby will move farther north, bringing heavy rain to Virginia, Washington, D.C., and Pennsylvania.

By Friday afternoon, the heavy rain will reach Philadelphia, New York City, upstate New York and New England.

Debby is then expected to move northeastward into Canada late on Friday night.