New York, Aug 9 (IANS): Tropical storm Debby has weakened to a depression following its second landfall in South Carolina, according to an advisory by the US National Hurricane Center.

Though a major flood threat continues for parts of South Carolina, North Carolina and western Virginia, all tropical storm warnings have been discontinued as of 5 p.m. Eastern time, said the advisory, Xinhua news agency reported.

The depression now has maximum sustained winds of 35 miles per hour and is moving northward at the speed of 10 miles per hour.

A faster northward or north-northeastward motion is expected during the next day or two, and Debby is expected to become a post-tropical cyclone on Friday, said the advisory.

So far, Debby has led to the death of at least six people in the United States, and the federal government has approved disaster declarations for Florida, Georgia, South Carolina and North Carolina to deal with its impacts.