Tropical Storm Arthur neared hurricane strength Thursday as it moved up the US East Coast just in time to dump heavy rain on the July 4 holiday.
The National Hurricane Center said in a news update at 0600 GMT that Arthur, now off the coast of South Carolina, was expected to become a hurricane "soon."
Residents and tourists along coast and looking forward to long weekends at the beach for US Independence Day were forced to consider changing their plans ahead of the storm.
News reports said that as many as half a million visitors had been expected to pack Carolina beaches for the national holiday, the region's biggest tourist weekend.
At 0600 GMT, Tropical Storm Arthur was 140 miles (230 kilometers) southeast of Charleston, South Carolina with maximum sustained winds of 70 miles (110 kilometers) per hour.
Arthur was moving toward the north at eight miles (13 km) per hour and was expected to pick up speed. Its core was due to approach the coast Thursday night, the hurricane center said.
A storm surge of up to four feet (1.2 meter) of water was possible in North Carolina's popular Outer Banks resort region. Through Friday, rainfall accumulation of up to six inches was expected in coastal areas of North Carolina.
The storm is the first of the Atlantic hurricane season, which started on June 1 and runs through November 30.