The latest flash flood predictions for Friday and Saturday. After criticism for its response in Puerto Rico to last year's Hurricane Maria, which officials there said was responsible for 3,000 deaths, Trump has vowed a vigorous response to Florence and defended his handling of Maria.
The center said the threat of freshwater flooding will increase over the next several days.
Hurricane-force winds now extend up to 80 miles and tropical-storm-force winds extend up to 195 miles from the center of the storm.
It is the storm's movement and not its strength that has forecasters and officials anxious.
GOES-East is one many satellites in orbit tracking the hurricane as it approaches the Carolinas.
Hurricanes can push masses of water from the sea over land when they come ashore, raising local sea levels by as much as 20 feet (6 meters), according to the National Hurricane Center. Already, the hurricane has triggered more than 1,000 flight cancellations and the closing of almost a dozen airports in North Carolina and SC. Millions of people were expected to lose power from the storm and restoration could take weeks.
Air Force General Terrence J O'Shaughnessy, head of US Command, said search and rescue is a top priority but that the magnitude of the storm may exceed the ability of rescuers.
"We're a little anxious about the storm surge so we came down to see what the river is doing now", Smith said. Tropical Storm Olivia made a double landfall in Hawaii Wednesday morning, first in west Maui then Lanai, KHNL reports.
The Pentagon has dispatched two ships and a Marine unit offshore to provide help if needed.
Numerous communities throughout the region have issued either mandatory or voluntary evacuation orders. Officials from the Federal Emergency Management Agency (Fema) have warned that failure to do so could be potentially deadly. "Disaster is at the doorstep and is coming in", he said in a tweet.
The police chief of a barrier island in Florence's bulls'-eye said he was asking for next-of-kin contact information from the few residents who refused to leave. "We're able", he said.
Of course, these various components blend together to cause maximum, and long-standing, devastation-which is what makes prudent pre-storm measures, and sustained post-storm aid, so critical to preserving human life.
According to the NHC's forecast discussion at 12 p.m. on September 13: "The subtropical ridge to the northeast and east of Florence is now well-established between Bermuda and the USA mid-Atlantic region and extends westward into Virginia and the central Appalachians".