SOME 1.7 million people in the US have started preparing for Hurricane Florence’s arrival.

Florence is expected to strengthen into a near-Category 5 storm, which is likely to bring “life-threatening, catastrophic flash flooding and significant river flooding” on Thursday and Friday.

President Donald Trump has declared states of emergency across North and South Carolina and Virginia, saying the US government is “absolutely, totally prepared” for the hurricane.

At 8am local time today, the storm was centred 530 miles south east of Cape Fear, approaching the coast of North Carolina at 17mph.

The National Hurricane Centre said it was a potentially catastrophic Category 4 storm, but was expected to keep drawing energy from the warm water and intensify to near Category 5 – meaning winds could reach speeds of 157mph or even higher.

The coastal surge from Florence could leave the eastern tip of North Carolina under more than 9ft of water in spots, projections showed.

The hurricane is forecast to dump 1ft to 2ft 6in of rain that could cause flooding well inland and wreak environmental havoc by washing over industrial waste sites and farms.

Motorists streamed inland and politicians pleaded with the public to take the warnings seriously.

“This storm is a monster. It’s big and it’s vicious. It is an extremely dangerous, life-threatening, historic hurricane,” North Carolina governor Roy Cooper said.

He added: “The waves and the wind this storm may bring is nothing like you’ve ever seen. Even if you’ve ridden out storms before, this one is different. Don’t bet your life on riding out a monster.”

More than 5.4m people live in areas under hurricane warnings or watches on the US east coast, according to the National Weather Service, and another four million were under a tropical storm watch.

North and South Carolina and Virginia ordered mass evacuations along the coast, but getting out of harm’s way could prove difficult as a result of the size of Hurricane Florence.

Florence is so wide that a life-threatening storm surge was being pushed 300 miles ahead of its eye, and so wet that a swathe from South Carolina to Ohio and Pennsylvania could get deluged.

People across the region rushed out to buy bottled water and other essential supplies, board up their homes, pull their boats out of the water and get out of town.

A line of heavy traffic moved away from the coast on Interstate 40, the main route between the port city of Wilmington, North Carolina, and inland Raleigh.

Between the two cities, about two hours apart, the traffic flowed smoothly in places and became gridlocked in others because of minor collisions.

Only a trickle of vehicles was going in the opposite direction, including pick-up trucks carrying plywood and other building materials.

Long lines formed at service stations and fuel supplies were low.

“This one really scares me,” National Hurricane Centre director Ken Graham said.

Federal officials urged residents to put together emergency kits – made up of non-perishable food, water, flashlights, sleeping bags and other key items – and know where to go.

“This storm is going to knock out power days into weeks. It’s going to destroy infrastructure. It’s going to destroy homes,” said Jeff Byard, an official at the Federal Emergency Management Agency.

Forecasters said parts of North Carolina could get 20in of rain, if not more, with as much as 10in elsewhere in the state and in Virginia, parts of Maryland and Washington DC.

The trusted European simulation model predicted more than 45in in parts of North Carolina.

The European model was accurate in predicting 60in for Hurricane Harvey in the Houston area in 2017.

Duke Energy spokesman Ryan Mosier said operators would shut down nuclear plants two hours before hurricane-force winds arrive.