The hurricane centre said Florence will approach the coast Friday and linger for a while before rolling ashore.
According to Wednesday morning's update from the National Hurricane Center, Florence could park off the coast of the Carolinas on Friday, bringing damaging winds and even extreme storm surges to coastal areas.
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"We still have to be at the read to brace for impact in case we get a hurricane too", Manley said. Its new path indicates that after arriving in the area near Wilmington, North Carolina, the storm will dip to the south before resuming a western course, the FWS explained in the statement.
Fox News reported that sustained winds were picking up a bit along the North Carolina coast.
The Miami-based NHC stressed, however, that while a slow weakening is expected over the next 24 hours "Florence is still forecast to be an extremely risky major hurricane when it nears the U.S. coast late Thursday and Friday".
More than one million people have been told to evacuate the Carolina and Virginia coastlines, while residents were desperately pulling shutters down over schools and factories.
"This is going to be a Mike Tyson punch to the Carolina coast", said Jeff Byard, associate administrator for response and recovery at the Federal Emergency Management Agency.
A state of emergency has been declared in both North and SC.
"So I don't really want to take no chances on it".
It has forecasted that parts of North Carolina could receive as much as up to one metre (40 inches) of rain.
Hurricanes are massive storm systems that form over warm ocean waters and move toward land. Eventually, Florence will veer north into the Appalachian Mountains, bringing soaking rains to Virginia and western North Carolina, before sputtering out late next week near DE and Maryland, the FWS reported. Rather than pushing up toward western Virginia, the storm's center is now predicted to move across the middle of SC.
However, he reiterated that just that minor factor alone is not enough to cause the cyclone to make major changes.
As of 8 a.m. ET, Florence was 530 miles southeast of Cape Fear, N.C., moving west-northwest at 17 mph, the National Hurricane Center says.