Former hurricane Hermine churned Saturday off the US East Coast, killing a second victim as it threatened deadly flooding and spoiled beach plans for the summer's last holiday weekend.

Hermine, now a post-tropical cyclone, was moving across the Outer Banks of North Carolina in an east-northeasterly direction at approximately 12 miles (19 kilometers) per hour, the Miami-based National Hurricane Center said.

The storm's latest fatality occurred when winds estimated between 60 to 70 mile per hour blew an 18-wheeler across highway lanes in North Carolina and propelled the cab into the railing of a bridge, killing the unidentified driver, Tyrrell County Sheriff Darryl Liverman told AFP.

The death brings the storm's casualties to two, after a homeless man was killed by a falling tree Friday in Florida.

Already packing sustained wind gusts maxing at 70 miles per hour, Hermine threatens deadly flooding along the East Coast.

"Hermine is expected to intensify to hurricane force on Sunday," the NHC said in its latest bulletin.

The Miami-based service also warned of an anticipated dangerous storm surge in the next 36 hours along the coast from Virginia to New Jersey.

Hermine was a hurricane when it slammed into Florida's Gulf of Mexico coast early Friday, causing street flooding and power outages, the southeast state's first hurricane landfall since 2005.

It was downgraded later that day to a tropical storm as it moved north.

Hermine was expected to lose forward speed and then "meander" offshore of the mid-Atlantic coast into Sunday, the center said.

Forecasters say the storm could dump up to seven inches (nearly 18 centimeters) of rain over parts of Virginia and Maryland through Monday morning.

Virginia Governor Terry McAuliffe declared a state of emergency Friday under the potential threat of damaging high winds, heavy rainfall and a dangerous storm surge and flooding.

"I urge Virginians to limit travel as the severe weather arrives and evacuate if recommended by officials," he said.

Maryland Governor Larry Hogan declared a state of emergency for coastal areas.

Hermine brought bad news for throngs of travelers hoping to enjoy beach time on the three-day Labor Day weekend, the unofficial end of the US summer vacation season.

Large waves likely to cause life-threatening surf and rip currents are expected from the mid-Atlantic states to southern New England, the NHC said.

Hermine is the fourth Atlantic hurricane of 2016. The last hurricane to make landfall in the United States was Arthur in 2014 in North Carolina.

Hermine fells trees, blows out power, leaves one dead in US
Miami (AFP) Sept 2, 2016 - Hermine uprooted trees, flooded streets and blew out power Friday as the hurricane swept across Florida's Gulf coast, grinding down to a tropical storm as it moved north.

A homeless man was killed by a falling tree, Florida Governor Rick Scott said.

There were no other reports of injuries but emergency crews worked "non-stop" overnight, rescuing 18 people from rising flood waters in Florida's Pascoe country, and several families in Hernando County, Scott said.

"Today, we know there is a lot of work left to do following this storm," the governor said in a statement.

"The number one thing is to stay safe," he said. "Life-threatening coastal flooding and rip currents will continue and we must all remain vigilant."

Overall, the region appeared to have weathered the storm well, to the relief of local officials.

"Things are great here," said Van Johnson, the mayor of Apalachicola, near where Hermine roared ashore at hurricane strength around 1:30 am local time (0530 GMT).

"We didn't experience any of the expected storm surges, damage to property," he told CNN. "The city fared well."

Crews were out clearing away fallen trees and branches, and looking for downed power lines.

Scott said 253,000 people were without power.

"Stay out of standing water especially near power lines," Scott advised Floridians.

Tallahassee mayor Andrew Gillum said many power lines and trees were down and 100,000 customers left without electricity in his area.

"Our crews are right now out and surveying the damage," he told CNN.

He warned residents to stay inside while authorities ensured there was no threat from downed power lines and other potential dangers.

- Heading along US East Coast -

At 2100 GMT, Hermine was 30 miles (50 kilometers) northwest of Charleston, South Carolina and moving along the Atlantic coast at 20 miles per hour (30 kilometers per hour).

The storm was packing sustained winds of 50 miles per hour, the Miami-based National Hurricane Center said, warning of possible storm surges.

Hermine threatened to bring heavy rains, flooding and tornadoes up the East Coast on the country's summer-ending Labor Day weekend.

A tropical storm warning was issued for areas as far north as Sandy Hook, New Jersey, a beach resort area located 40 minutes by ferry from New York.

"There is a danger of life-threatening inundation during the next 48 hours" in coastal areas from North Carolina to Connecticut, the NHC said.

Georgia has declared a state of emergency in 56 counties, and North Carolina in 33 counties.

Pentagon spokesman Jeff Davis said 100 Florida National Guard personnel were activated, with 6,000 more on alert in the state and 34,000 ready to deploy from elsewhere in the United States.

President Barack Obama has asked FEMA administrator Craig Fugate to keep him updated on the situation "and to alert him if there are any significant unmet needs", said White House spokesman Josh Earnest.

Hermine was expected to veer off the North Carolina coast by Saturday afternoon.

The hurricane was the first to hit Florida in 11 years since Wilma in 2005.

Its winds rose up to 80 miles per hour before it came ashore just east of the town of St Marks on Florida's Apalachee Bay.

Local television stations broadcast footage of buffeting winds, lashing rain and flooded streets.

Hermine is expected to dump five to 10 inches (12 to 25 centimeters) of rain over the southeastern United States, with possible isolated maximum amounts of 15 inches.

The last hurricane to make landfall in the United States was Arthur in 2014 in North Carolina.