Even with some weakening that is predicted just before it makes landfall, the storm "is expected to remain a risky major hurricane as it approaches the coastline", the hurricane center said.
The video was taken on Tuesday as Florence churned across the Atlantic in a west-northwesterly direction with winds of 130 miles per hour.
With state governments in SC and North Caroline issuing evacuations along the coast and other potential flood zones, the Federal Emergency Management Agency (FEMA) has said that it is mobilizing for a storm that could knock out power for weeks and lead to the displacement of tens if not hundreds of thousands of residents across multiple states.
An Oklahoma search and rescue helicopter team left Wednesday for Hurricane Florence and will be stationed in Tennessee and the Carolinas along the East Coast to respond as needed, the Oklahoma City Fire Department reported.
Residents prepared by boarding up their homes and stocking up on food, water and other essentials, stripping grocery store shelves of merchandise.
Water kills more people in hurricanes than wind, and the rain and storm surge will make Florence extremely risky.
The forecast calls for as much as 40 inches (102 centimeters) of rain over seven days along the coast, with the deluge continuing even as the center of the storm pushes its way over the Appalachian Mountains.
Forecasters said that given the storm's size and sluggish track, it could cause epic damage akin to what the Houston area saw during Hurricane Harvey just over a year ago, with floodwaters swamping homes and businesses and washing over industrial waste sites and hog-manure ponds.
States up and down the East Coast have a great potential for severe weather.
"This is going to be a Mike Tyson punch to the Carolina coast", said Jeff Byard, the associate administrator for response and recovery at the Federal Emergency Management Agency (FEMA).
Rain measured in feet is "looking likely", he said.
About 10 million people could be affected by the storm.
A buoy off the North Carolina coast recorded waves almost 30ft high as Florence churned toward shore.
Paula Matheson of Springfield, Oregon, got the full Southern experience during her 10-week RV vacation: hot weather, good food, lovely beaches and, finally, a hurricane evacuation.
In North Carolina, the state Department of Information Technology is bracing for inevitable power outages by supplying the Transportation and Environmental Quality departments with generators to keep traffic signals, road-alert signs and other critical equipment functioning, the IT agency told StateScoop. The water was fabulous. "I guess that's a big part of the problem".
Florence's top sustained wind speeds dropped from a high of 140mph to 110mph which reduced the hurricane's power from Category 4 to Category 2. Winds are dicey at times in Long Island around that timeframe, with New England and the Canadian Maritimes seeing lighter, more favorable winds at times.
In the six decades since, many thousands of people have moved to the coast.
Duke Energy spokesman Ryan Mosier said operators would begin shutting down nuclear plants at least two hours before hurricane-force winds arrive. "Disaster is at the doorstep and it's coming in".