Forecasters with the National Hurricane Center said that while Florence is expected to slow down considerably by late Thursday and into Friday, it will still be an "extremely risky major hurricane" when it makes landfall.
Florence had maximum sustained winds of 130 miles per hour (215 km per hour) and was on a trajectory that showed its center most likely to strike the southern coast of North Carolina by Friday, the National Hurricane Center said.
Large and risky, Hurricane Florence is drawing closer to the coast of the Carolinas, where it threatens to become the most intense storm to strike the region in at least 25 years, since Hugo.
Officials in at least one area that ordered an evacuation will be going to homes to ask people planning to ride it out for information on their next of kin, CNN reported Wednesday.
"It's chilling, even from space", said Alexander Gerst, an astronaut with the European Space Agency who now lives on ISS, on Twitter. Parts of North Carolina could get 40 inches (1 meter) of rain.
Hurricane Florence's potentially devastating winds are generating enormous waves as high as 83 feet as it continues to make its way toward the East Coast and insurers predict it will become the costliest such storm to ever hit the continental U.S.
It was downgraded to a Category 1 hurricane before coming ashore near Wrightsville Beach close to Wilmington, North Carolina.
"I'm scared we'll get 30 inches or more of rain", said Carol Trojniar, 69, a longtime Wilmington resident and retired real estate agent who has never experienced a Category 4 hurricane.
Crews also prepared 16 nuclear reactors in the three-state region for the storm.More news: Carlos Ramos, umpire involved in US Open final controversy, returns to court
Trump declared states of emergency for North and SC and Virginia, opening the way for federal aid.
Florence is now heading for ocean water that has surface temperatures of about 85 degrees, meaning it will most likely strengthen on its way to the East Coast.
The shift south and west will encompass more of SC and western North Carolina.
"Rather than a very narrow and intense band of winds, the winds are slightly weaker - but [they] cover a much larger area", NHC senior hurricane specialist Stacy Stewart said on Wednesday.
Hurricane Florence has inundated USA coastal streets with ocean water and left tens of thousands without power, and forecasters say conditions will only worsen as the hulking storm slogs inland.
The storm's surge, the rise in sea water above normally dry land at the coast, could reach up to 13 feet at peak.
Hurricane-force winds now extend up to 80 miles from the eye of the storm, and tropical-storm-force winds now extend up to 195 miles from the center of the storm.
As Florence closed in, President Donald Trump and state and local officials urged residents in the path of the storm to evacuate before it was too late. She said a hurricane has a way of bringing everyone to the same level.
"This rainfall would produce catastrophic flash flooding and significant river flooding", the Miami-based National Hurricane Center (NHC) said.