About 10 million people could be affected by the storm and more than 1 million had been ordered to evacuate the coasts of the Carolinas and Virginia, jamming westbound roads and highways for miles.
And when it comes to impacts like storm surge, size matters just as much as the winds, says Rick Luettich, a coastal physical oceanographer at University of North Carolina Chapel Hill's Institute of Marine Sciences. Hurricane-force winds extend up to 80 miles from the centre, and tropical storm effects reach 195 miles, The Independent reported.now less than 100 miles from Wilmington, North Carolina, the "meandering" Florence has been described as a "horrific nightmare storm" because meteorologists can not pinpoint where it will strike.
Operations at the ports of Wilmington, Charleston, South Carolina, and Norfolk in Virginia, which together handled 23 per cent of East Coast imports in 2017, have been disrupted by the storm.
Hurricane Florence made landfall in North Carolina Friday morning with a life-threatening storm surge that pushed water inland for miles, pelting rains and screaming winds that destroyed buildings in its path.
The storm's centre was about 180km east of Wilmington, North Carolina, at 2pm local time (18:00 GMT) but tropical storm-strength winds and heavy rains already were hitting North Carolina's Outer Banks barrier islands.
The administration said that as Florence, a Category 2 storm, is expected to make landfall in the USA southeast coast on Friday, the massive storm will obstruct electricity transmission and distribution, while widespread evacuations and disruptions to normal business operations could impact demand patterns for transportation fuels.
North Carolina governor Roy Cooper urged residents to remain alert despite changing forecasts.
Reports said coastal streets in North Carolina were flooded and winds bent trees to the ground as the storm, which has been downgraded to Category 1 and is weakened and slower moving than in recent days, prepared to make landfall at some point on Friday.
Hurricane Florence will be one of the biggest storms to make landfall along the U.S. eastern seaboard in decades. "We just want prayers from everyone".
Ken Graham, director of the hurricane center, said on Facebook the storm surges could push in as far as 3 kilometers (2 miles).
The NHC's latest statement warned a combination of a unsafe storm surge and the tide will cause normally dry areas to be flooded, with water levels expected to reach between 7 and 11 feet between Cape Fear and Cape Lookout in North Carolina, and higher in the Neuse, Pamlico, Pungo and Bay Rivers.
Despite pleas from officials, some residents rejected calls to evacuate.
Duke Energy Co. said Florence could knock out electricity to three-quarters of its 4 million customers in the Carolinas, and outages could last for weeks.
Emergency declarations were in force in Georgia, South and North Carolina, Virginia, Maryland and the District of Columbia. "I'm not leaving him here".
"Some areas we can't get to at all", said Amber Parker, a spokeswoman for Craven County Emergency Management told broadcaster MSNBC. "I learned from the past to keep the ice in the washing machine".
"I do worry though about people here because many didn't prepare, you know, because originally they didn't think it was going to be so bad here", Sparks said. "I charged the batteries of my electronic devices, I have beers and video games".