MIAMI: Hurricane Arthur made landfall on the North Carolina shore, packing 100 mph (160 kph) winds and drenching rains in an onslaught dampening America's July 4 celebrations.
The US National Hurricane Center said the first hurricane of the Atlantic season carried potential for big and damaging waves and powerful tidal surges as it came ashore late Thursday.
It hit the Outer Banks, a series of long and thin barrier islands that are a popular resort area. Tens of thousands of people had hoped to enjoy the US independence day holiday there.
But some evacuations had been ordered even as the hurricane approached. It finally came ashore as a category two hurricane, on a scale in which five is the highest.
Arthur was expected to keep moving up the East Coast but weaken into a cyclone Friday night on Saturday as it approaches Nova Scotia in Canada.
North Carolina state Governor Pat McCrory said emergency preparation efforts had been made more complicated by the arrival of thousands of tourists who do not know the local roads well.
Heavy rain and strong winds lashed the North Carolina coast.
Thousands of people were already without power in North Carolina, news reports said, and there was localized flooding in areas including the coastal city of Wilmington.
"Our main issue is the health and safety of our citizens and those people who are visiting North Carolina," McCrory said.
Emergency declarations were issued by several counties in the southern state, which opened emergency shelters and ordered evacuations in low-lying areas.
"As the hurricane moves north, more counties are likely to declare a state of emergency," McCrory added.
National Hurricane Center forecasters warned of "large and damaging waves" and cautioned: "Preparations to protect life and property should have already been completed."
McCrory Wednesday urged residents and tourists to use common sense, to stay out of the water and out of harm's way, with storm surges of up to five feet (1.5 meters) predicted.
Up to eight inches (20 centimeters) of rain were expected in coastal areas.
"Don't put your 'stupid hat' on," McCrory said.
"Let's hope for the best, pray for the best, that Arthur clears out quickly so we can all get back to celebrating our country's independence, with our families and friends on North Carolina's beautiful beaches."
As many as half a million visitors had been expected in the coastal Carolinas for the national holiday, the region's biggest tourist weekend.
Authorities issued a mandatory evacuation order for Hatteras Island and a voluntary evacuation order for Ocracoke Island, both in North Carolina's Outer Banks, CNN reported.
But it was not just North Carolina -- where tornado warnings were activated in some areas -- that was bracing for Arthur's impact.
The storm threatened to scuttle traditional Independence Day weekend picnics, parades and fireworks displays for millions of Americans along the East Coast, as far north as New England.
Dangerous storm swells were expected as far south as central Florida, weather officials said.
The Atlantic hurricane season began June 1 and runs through November 30.