"Florence has rapidly intensified into an extremely risky hurricane", Blake wrote Monday evening, predicting that the hurricane's top sustained winds would approach the 157 miles per hour (253 kph) threshold for a wost-case Category 5 scenario.
The office of Virginia Governor Ralph Northam predicted "catastrophic inland flooding, high winds and possible widespread power outages".
"The centre of Florence will move over the southwestern Atlantic Ocean between Bermuda and the Bahamas Tuesday and Wednesday, and approach the southeastern coast of the United States on Thursday", the NHC said. The National Weather Service reported Sunday that more than 20 people had to be pulled from the ocean off Wrightsville Beach and Carolina Beach, The Wilmington Star reported. The center of the massive storm is then forecast to meander Thursday, Friday and Saturday over a stretch of coastline saturated by rising seas.
Florence is "rapidly strengthening", with maximum sustained winds increasing to 170km/h, making it a category 2 storm, the second-weakest on the five-level Saffir-Simpson hurricane scale. But authorities warned it will still be an extremely risky hurricane.
Families should prepare their emergency kits (keep scrolling for a list of items to put in them) and determine what they will do in case of a necessary evacuation.
"Not only has the storm exploded in intensity, but its zone of hurricane-force winds approximately doubled in size Monday", the Washington Post reports.
According to the National Weather Service, other evacuations along the Outer Banks will go into effect on Tuesday.
Trump says the federal government is "absolutely, totally prepared".
"Don't play games with it. That's my one and only dealing with a hurricane".
North Carolinians are urged to use the next couple of days to get ready for the storm, including reviewing emergency plans and gathering supplies.
The uncertainty of exactly where Florence will cross land is linked to a high pressure system steering the storm away from what would normally be a turn northward.
Major US military installments may be in the path of the Florence, including the largest Marine base at Camp Lejeune in North Carolina and the world's biggest Navy base in Norfolk, Virginia.
Airline fares typically rise as flights sell out.
"This storm gets stronger and stronger" on its way to a head-on impact with a zone that ranges some 80 miles, Myers said. The two hardware chains said they sent in a total of around 1,100 trucks.
Their deployment can last from a few days to a few weeks.
A hurricane watch is in effect from Edisto Beach, South Carolina, to the South Santee River.
The store, she said, was starting to run out, and was limiting each customer to 12 pieces. Hurricane warnings are issued 36 hours before tropical storm force winds hit the areas, and indicate hurricane conditions will follow.
"Let me be clear: North Carolina is taking Hurricane Florence seriously and you should too", Mr Cooper said at a news conference.
The shift in the projected track spread concern to areas that once thought they were relatively safe. The president has spoken to the governors of both Carolinas and Virginia, the White House said Monday.
"We've had our lessons".