The forecasters have also warned that the expected rainfall could reach up to 40 inches and the storm is expected to slowly move southwest into SC before turning north.
Hurricane Florence is set to inundate nearly all of North Carolina in several feet of water, State Governor Roy Cooper told a news conference, while National Weather Service forecaster Brandon Locklear predicted up to eight months' worth of rain in two or three days. His state has already endured record rainfall, with much more forecast to come.
Hurricane Irma destroyed Kathy Griffin's house in Florida a year ago, and it could be days before she finds out whether Florence smashed her fifth-story condominium in Wrightsville Beach, where authorities said utilities could be out for days or weeks.
In South Carolina, 155,000 customers are without power, officials said.
With flood waters advancing rapidly in many communities, stranded people were being rescued by boat and by helicopter, while tens of thousands of others hunkered down in shelters.
Rivers and creeks rose toward historic levels, threatening flash flooding that could devastate communities and endanger dams, roads and bridges.
Utility crews worked to restore electricity.
The death toll attributed to Florence stands at 11, including 10 in North Carolina and one in SC.
Evacuation orders remain in place for Horry and Georgetown counties along South Carolina's northern coast.More news: Spain vs. Croatia - Football Match Report
Florence's top winds were clocked on Thursday evening at 90 miles per hour (150 km/h) as it churned in the Atlantic Ocean, down from a peak of 140 miles per hour (224 km/h) earlier this week when it was classified a Category 4 storm. It said it was located about 60 miles west of Myrtle Beach, South Carolina, and forecasters predicted a slow westward march. Hurricane-force winds extended 80 miles from its centre, and tropical-storm-force winds up to 195 miles.
Florence's rain will be relentless, with up to 40 inches expected in some parts of the Carolina coasts, forecasters said.
Storm surges were forecast to be at their peak Thursday night just before midnight and Friday around noon, according to NBC News' Al Roker. The difference between high and low tide is about 4 feet on the North Carolina coast, so timing is important. On Saturday, its streets were strewn with downed tree limbs and carpeted with leaves and other debris. More are on the way to help us.
"The fact that there haven't been more deaths and damage is fantastic and a blessing", said Rebekah Roth, walking around Wilmington's Winoca Terrace neighborhood.
Florence's center may linger for another whole day along the Carolinas' coast - punishing homes with crushing winds and floods and endangering those who've stayed behind. Florence is nearing the coast and is now a Cat 2 Hurricane. Floyd produced 24 inches of rain in some parts of the state, while Florence has already dumped about 30 inches in areas around Swansboro.
News 6's Erik Sandoval was live in Wilmington shortly before the storm made landfall. Some area residents described a harrowing retreat as the storm hit.
The Category 1 storm officially made landfall near Wrightsville Beach, North Carolina, shortly before 7:45 a.m.
SC authorities said law enforcement officers were guarding against looting in evacuated areas, while Wilmington set a curfew on Saturday evening in response to looting in one area.
At 8 a.m., the center of Florence was 10 miles (15 kilometers) south of Wilmington.
"In a matter of seconds, my house was flooded up to the waist, and now it is to the chest", she said. Trump plans a visit to the region next week.