The hurricane has already reached category 4, with winds up to 130 miles per hour.
Beyond the damage from wind and high surf, Hurricane Florence is anticipated to slow over the Carolinas where it might dump up to 30 inches of rain over quite a bit of North and SC.
Henry McMaster issued a mandatory evacuation ahead of Hurricane Florence for all coastal counties in SC on Monday, including Beaufort, Colleton, and Jasper counties.
Swells from the storm are already reaching Bermuda and parts of the US coast.
Florence will bring a perilous risk of flooding to a broad area, and its wind and rains will also bring downed trees and other destruction to areas in its path, the hurricane center said.
HURRICANE Florence could intensify yet again with the monster storm on the brink of a Category 5, prompting evacuations of more than one million people in the USA to higher ground.
South Carolina's governor ordered the state's entire coastline to be evacuated starting at noon Tuesday and predicted that 1 million people would flee. Certain areas of Brunswick, Currituck, Dare, Hyde, New Hanover, and Onslow counties are affected, and more orders are expected Tuesday.
I say "active" hurricanes because there are more storms out there that could mature into a hurricane.
Gulf Coast prepares for Gordon's expected arrival as hurricane
Miami Beach Police said via Twitter that the Labor Day holiday was "NOT a beach day", with rough surf and potential rip currents. Rain and the flash flooding that can cause are the main threats expected from Gordon along with strong wind and storm surge.
On Sunday, South Carolina's state emergency management agency tweeted it was "preparing for the possibility of a large-scale disaster".
States of emergency were declared in the Carolinas, Virginia and Maryland. Florence was upgraded twice Monday to a Category 4.
Florence could hit the Carolinas harder than any hurricane since Hazel packed 130 miles per hour (209 kph) winds in 1954.
"They cancelled school for the rest of the week here, so we'll probably head out later today or tomorrow", one man said.
In Holden Beach, North Carolina, in the storm's path, longtime residents were boarding up homes and securing possessions.
Hurricane-force winds extend outward up to 30 miles from the center and tropical-storm-force winds extend outward up to 140 miles.
North and SC are expected to be hardest hit on Thursday, with evacuations ordered by South Carolina's governor Henry McMaster.
The NHC warned they're likely to cause "life-threatening surf and rip current conditions".
It could be the worst hurricane to hit the Carolinas in over 60 years.