The storm officially made landfall near Wrightsville Beach, North Carolina at 7:15am local time, the National Hurricane Centre (NHC) said
Hurricane Florence has smashed into the US East Coast with howling winds, torrential rains and life-threatening storm surges as emergency crews scrambled to rescue hundreds of people stranded in their homes by flood waters.
The storm hit on Friday and forecasters warned of catastrophic flooding and other mayhem from the monster storm, which is only Category 1 but physically sprawling and dangerous.
The port city of Wilmington woke Friday to the sound of exploding electrical transformers with strong gusts throwing street signs and other debris as well as water in all directions, according to a reporter at the scene.
The storm officially made landfall near Wrightsville Beach, North Carolina at 7:15am local time, the National Hurricane Center (NHC) said.
Ken Graham, the NHC's director, warned the slow pace of the storm exacerbated its danger even to areas outside its immediate path. "The longer you have this hurricane wind flow, the longer you push that water well inland," he said.
Rescue workers in North Carolina meanwhile were scrambling to save people stranded in their homes. Video footage showed parking lots in the riverfront town of New Bern turn into shallow lakes of dirty gray water as heavy rain fell.
In its 1200 GMT advisory, the centre said Florence was packing winds of 150km per hour and moving northwest at 10km per hour.
It added the greatest threats to life came from storm-surges while "catastrophic flash flooding and prolonged significant river flooding" was expected, with some areas receiving up to 40 inches of rainfall.
With winds picking up along the coastline earlier Thursday, federal and state officials had issued final appeals to residents to get out of the path of the "once in a lifetime" weather system.
"This storm will bring destruction," North Carolina Governor Roy Cooper said. "Catastrophic effects will be felt."
Monster storm surge expected
The NHC said hurricane-force winds extended outward 130km from the centre of the storm and tropical storm-force winds extended nearly 314km out.
A tornado watch was also in effect for parts of North Carolina.
Brock Long, the administrator of the Federal Emergency Management Agency (Fema), warned the danger was not only along the coast: "Inland flooding kills a lot of people, unfortunately, and that's what we're about to see," he said.
About 1.7 million people in North Carolina, South Carolina and Virginia are under voluntary or mandatory evacuation orders and millions of others live in areas likely to be affected by the storm.
A state of emergency has been declared in five coastal states - North Carolina, South Carolina, Georgia, Maryland and Virginia.