At least four people have died, and authorities fear the toll will go higher.
"The wind was so hard, the waters were so hard, that trying to get out we got thrown into trailers. I was looking for water moccasins to hit me at any time", he said.
Storm surges - the bulge of ocean water pushed ashore by the hurricane - were as high as 10 feet (3 meters).
The storm roared ashore under the cover of darkness, pummeling the region with pounding rain, widespread flooding and catastrophic winds.
The National Weather Service warned of "life-threatening, catastrophic flash floods" as a staggering 18 trillion tons of rain could be dumped on the Mid-Atlantic through next week, enough to cover the entire state of Texas with almost 4 inches of water.
Relief will not come quickly. The rivers are in most cases several days from cresting. Meteorologist Ryan Maue of weathermodels.com estimates Florence could dump about 18 trillion gallons (68 trillion liters) of rain.
Southwestern Virginia is also expecting up to 10in (25cm).
There is really nowhere for the water to go.More news: 'PREPARE TO DIE': Leftists' Heads Explode Over Trump Alert
As of Saturday morning, the storm had dumped over 30 inches of rain in parts of North Carolina.
Tornadoes remain a threat, with the NHC saying that "a few tornadoes are possible in southeastern North Carolina and northeastern SC".
"WE ARE COMING TO GET YOU", the tweet said.
With flood waters rising rapidly in many communities, stranded people were being rescued by boat and by helicopter, while tens of thousands of others hunkered down in shelters. We got thrown into mailboxes. The Little River, the Cape Fear, the Lumber, the Neuse, the Waccamaw and the Pee Dee were all projected to overrun their banks, possibly flooding cities and towns.
In New Bern, about 90 miles northeast of Wilmington at the confluence of two rivers, Florence overwhelmed the town of 30,000 and left the downtown area under water. See social media posts from journalists and first responders.
A mother and baby were killed when a tree fell on their home in Wilmington.
In Kinston, a city southeast of Raleigh, two people died in the storm. And a 77-year-old man died when he was knocked over by wind, he said.
In South Carolina, a 62-year-old woman died when her auto hit a tree that had fallen across a road in the town of Union.
FEMA says such a notion is just a rumor. "Hurricane Florence is going to continue its violent grind across our state for days. Be extremely careful and stay alert". Electricity remained out for much of the city, known for its historic mansions, with power lines lying across roads like wet strands of spaghetti.More news: Mychal Kendricks visits Seahawks
Utility companies said millions were expected to lose power and restoration could take weeks.
"Know that the water is rising fast everywhere, even in places that don't typically flood", Cooper said. But Florence has been a odd one since it materialized in the distant Atlantic and took an unusual path toward the mainland United States.
"The one thing I want to prevent is thousands of people stranded on our interstates or USA routes", said state Transportation Secretary Jim Trogdan.
The coast has been battered, and the mountains appear to be next.
As of 6 a.m., Florence was centered just 10 miles (20 kilometers) east of Wilmington, North Carolina. "These are folks who chose to stay and ride out the storm for whatever reason, despite having a mandatory evacuation", city public information officer Colleen Roberts said. Florence could add another six to 10 inches of rainfall this weekend.
"If you are told to evacuate, please do so immediately".
"It's not often that we have to prepare for a hurricane in the mountains, but we are doing so on our campus", Jason Marshburn, the director of safety and emergency management at Appalachian State University in Boone, wrote in a letter to students and faculty members.
The storm is expected to turn west and then north moving through the Carolinas and the Ohio Valley by Monday, the NHC said early on Saturday.
This main threat - flooding - is coming into focus.More news: Weather Channel Defends Reporter As He Allegedly Exaggerates Report On Hurricane Florence