Hurricane conditions will likely hit the area around North Carolina's southern coast on Friday, but tropical storm conditions will arrive on Thursday, according to the hurricane center.
While many coastal residents heeded mandatory evacuation orders, others boarded up homes and businesses and chose to fearless the storm, which is forecast to trigger severe flash flooding as it dumps as many as three feet (almost a metre) of rain in some areas.
Crews also prepared 16 nuclear reactors in the three-state region for the storm.
Emergency preparations in SC now include more than 2,100 of the state's National Guard soldiers.
The National Weather Service said 5.25 million people live in areas under hurricane warnings or watches, and 4.9 million live in places covered by tropical storm warnings or watches. "This is a storm that is historic, maybe once in a lifetime".
Tropical Storm Florence dumped "epic" amounts of rain on North and SC as it trudged inland on Saturday, knocking out power and causing at least eight deaths as flood waters that have devastated many communities kept rising. In North Carolina, Cooper says, "2,800 soldiers will be on active duty, joined by even more on standby".
The eastbound lanes of several major highways have been shut down to allow for a smooth flow of traffic inland. Jeff Byard of the Federal Emergency Management Agency (FEMA) invoked a former boxing champion to warn residents that it would bring "a Mike Tyson punch to the Carolina coast". Reports from the Miami-based weather forecaster on Monday confirmed that the Florence is located about 1,880 kilometers southeast of Cape, however, Fear is now growing bigger in North Carolina.
"Just because we have a landfall to your south, that doesn't mean you're out of the woods, because the winds are huge around this system", NHC Director Ken Graham said, pointing out the wide risk of flooding.
Duke Energy, the nation's No. 2 power company, said Florence could knock out electricity to three-quarters of its 4 million customers in the Carolinas, and outages could last for weeks. "You're going to be displaced from your home in coastal areas".
In Virginia, where about 245,000 residents were ordered to evacuate low-lying areas, officials urged people to remain away from home despite forecast changes showing Florence's path largely missing the state. Thousands of marines and their families evacuated from Camp Lejeune, leaving the rest to dig in ahead of what could be a direct hit.
"The preparations for a hurricane began long before the past few hours or days", North Carolina Pork Council President Brandon Warren said in a statement.
The National Hurricane Center listed the massive storm moving west-northwest at 17 miles per hour with winds about 130 miles per hour, and expected to reach the coast Thursday night to Friday morning, The News & Observer reported.
President Donald Trump declared states of emergency for North and SC and Virginia, opening the way for federal aid.
Faced with new forecasts that showed a more southerly threat, Georgia's governor joined his counterparts in Virginia and North and SC in declaring a state of emergency, and some residents who had thought they were safely out of range boarded up their homes.
"Bad things can happen when you're talking about a storm this size", Trump said Wednesday morning.
Michael Kennedy, an engineer at Boeing, said he planned to leave for his parents' home in Atlanta, Georgia. I work for the government, they've closed.