The storm was expected to move across parts of southeastern North Carolina and eastern SC on Friday and Saturday, then head north over the western Carolinas and central Appalachian Mountains early next week, the NHC said.
WILMINGTON, North Carolina - Hurricane "Florence" lumbered ashore in North Carolina with howling 90 miles per hour (145 kph) winds and terrifying storm surge early Friday, ripping apart buildings and knocking out power to a half-million homes and businesses as it settled in for what could be a long and extraordinarily destructive drenching. The father was taken to a nearby hospital with injuries. Some 3,000 people died in the aftermath of that storm.
"It's an uninvited brute who doesn't want to leave", said North Carolina Gov. Roy Cooper.
Florence was seen as a major test for the Federal Emergency Management Agency, which was heavily criticized as slow and unprepared a year ago for Hurricane Maria in Puerto Rico, where the storm was blamed for almost 3,000 deaths in the desperate aftermath.
Storm surge of up to 13 feet will be "life threatening" and rainfall of up to 40 inches will mean "catastrophic" flooding, according to the National Hurricane Center.
By late afternoon, the centre of the storm was about 25 miles northeast of Myrtle Beach, South Carolina, with maximum sustained winds of 70 mph.
Donald Trump was to visit hurricane-hit zones "early to the middle of next week", the White House said, "once it is determined his travel will not disrupt any rescue or recovery efforts". But it was clear that this was really about the water, not the wind.
On the forecast track, Isaac should move farther away from Lesser Antilles today, and then move across the eastern and central Caribbean Sea through the weekend.
About one million seven hundred thousand people have been ordered to evacuate on the coast of North Carolina, South Carolina and Virginia.
Hurricane Florence began lashing the coast Thursday morning, sending pounding waves ashore and rising storm surge.
"Afterwards, I'm going to drink a bottle of whiskey and take a two-day nap, but right now I'm walking the neighborhood and making sure my neighbors are fine, because nobody can get in here". Emergency declarations were in force in Georgia, South and North Carolina, Virginia, Maryland and the District of Columbia. "If the number seems really insane high, you always have to have some suspicion until we can actually get out and verify it".
On Friday, coastal streets in the Carolinas flowed with frothy ocean water, and pieces of torn-apart buildings flew through the air.