As many as 5,000 holidaymakers have been evacuated from Hatteras and Ocracoke Islands in the Outer Banks of North Caroline as Hurricane Earl approaches.
The storm is presently 410 miles south of Cape Hatteras moving north-by-northwest at 18 mile per hour according to the latest information from the National Hurricane Centre
Winds of 140 mph - the strongest of the Atlantic season - have been recorded, with Earl expected to hit North Carolina tonight before scraping Cape Cod and hitting Nova Scotia over the forthcoming Labour Day holiday weekend.
Earl is not forecast to strike the US mainland directly, but its swirling winds were expected to sideswipe the densely populated coast.
American president Barack Obama has declared a state of emergency as states along the United States eastern seaboard continue to prepare.
While the storm is only expected to glance the shoreline, officials are preparing evacuation plans should the hurricane come inland.
The US Department of Homeland Security and the Federal Emergencies Management Agency (FEMA) have both been authorised to co-ordinate disaster relief.
The move is designed to allow rapid movement of equipment and other resources if the hurricane threatens more densely-populated areas.
Further out to sea, the holiday destination of Bermuda has issued a tropical storm watch as Tropical Storm Fiona, with 50 mph winds, headed toward the islands.
Fiona is presently 670 miles south of Bermuda, moving northwest at 17 mph.