But the wind is not the main threat to people and property from the storm; it's thestorm surgeandrainfall, which combined have caused serious flooding in the low-lying coastal regions of the Carolinas.
State and Federal Emergency Management Agency officials, who have been on the ground in North Carolina for several days, already are talking about temporary housing options, state Division of Emergency Management director Mike Sprayberry said.
The states of Georgia, South Carolina, North Carolina, Virginia and Maryland, as well as Washington D.C., declared a state of emergency ahead of the storm.
North Carolina Governor Roy Cooper called Florence an "uninvited brute" that could wipe out entire communities as it grinds across the state.
The centre of the slow-moving storm, downgraded from a Category 1 hurricane after it came ashore Friday afternoon, was almost stalled over SC early Saturday, about 55 kilometres west of Myrtle Beach, moving west-southwest at just 8 km/h and scooping massive amounts of moisture from the sea.
"Just turn around and don't drown", officials said.
More than 415,000 homes and businesses were without power, mostly in North Carolina, according to poweroutage.us, which tracks the nation's electrical grid.
4 dead as Hurricane Florence drenches the Carolinas
People in the Carolinas had the daytime hours Thursday to complete their final preparations to ride out or escape the storm. At least 12,000 people had taken refuge in 126 emergency shelters, Governor Cooper said, with more facilities being opened.
North Carolina has been declared a disaster zone, with flooding expected to worsen in some areas. Electricity remained out for much of the city, known for its historic mansions, with power lines lying across roads like wet strands of spaghetti. The Little River, the Cape Fear, the Lumber, the Neuse, the Waccamaw and the Pee Dee were all projected to rise over their banks, flooding cities and towns.
About 10 million people could be affected by the storm.
Forecasters say catastrophic freshwater flooding is expected over parts of North Carolina and SC ahead.
The National Hurricane Center says excessive amounts of rain are still being dumped in North Carolina and the effect is expected to be "catastrophic". Later, Trump tweeted his condolences, writing, "Deepest sympathies and warmth go out to the families and friends of the victims".
"If you are refusing to leave during this mandatory evacuation, you need to do things like notify your legal next of kin because the loss of life is very, very possible", Mayor Mitch Colvin said.
Across the Trent River from New Bern, Jerry and Jan Andrews returned home after evacuating to find carp flopping in their backyard near the porch stairs.
In Jacksonville, North Carolina, next to Camp Lejeune, firefighters and police fought wind and rain as they went door to door to pull more than 60 people out as the Triangle Motor Inn began to crumble.
The figure included a woman and her baby killed when a tree fell on their house. "That's why we've been preaching to people that you have to get away from the water".