And while some people may think that Florence doesn't possess the same punch Harvey did since it's only a Category 2 storm, there is a comparison: Sandy.
According to CNN, Florence's center will approach the coasts of North and SC late Thursday and Friday, with the actual landfall expected to come on Friday afternoon. The National Weather Service said about 5.25 million people live in areas under hurricane warnings or watches, and 4.9 million in places covered by tropical storm warnings or watches.
Florence is the most risky of three tropical systems in the Atlantic.
Time is running short to get out of the way of Hurricane Florence, a monster of a storm that has a region of more than 10 million people in its potentially devastating sights as it zeroes in on the Southeastern coast. But, Hill added, those lane reversals will end soon: "At that point, they'll shut 'em down for the incoming storm".
"It's going to be bad", said Woody White, chairman of the New Hanover County Commissioners. "And that will produce a lot of damage as well as prolong the beach erosion".
FEMA has warned that while downgraded, the storm will still generate life threatening storm surge and rainfall in North and SC.
Now, residents of North Carolina could see flash flooding and over a foot of rain as the storm centres itself over the state. Then it dropped to an extratropical cyclone - but with hurricane-force winds akin to a low Category 1 hurricane - before making landfall in New Jersey.
"Been through it!" Belli said, referring to Hurricane Hugo, which caused widespread damage in SC in 1989.
"This is not going to be a glancing blow", Byard said, warning of power outages, road closures, infrastructure damage and potential loss of life.
The hurricane centre also said the threat of tornadoes was increasing as the storm neared shore.
Another video from NOAA's GOES-East weather satellite caught a different view of Hurricane Florence.
Hurricane warnings are in effect for the South Santee River in SC to Duck, North Carolina, and Albemarle and Pamlico sounds.
Slower movement means a hurricane has more time to inundate a region with rain and storm surge.
Gradually, Friday through the weekend (local time), the massive storm - containing a zone of tropical-storm-force winds almost 643km wide - will drift inland, engulfing much of SC and southern North Carolina. Then, it will likely hover along the coast Saturday, pushing up to 13 feet (nearly 4 meters) of storm surge and dumping 20 to 30 inches (50 to 75 centimeters) of rain on both states, before slogging over the Appalachian Mountains. Some flooding was forecast early in the day for parts of North Florida, but those forecasts were adjusted later to include high swells and minor coastal flooding at high tide.
Will Epperson, 36, a golf course assistant superintendent, said he and his wife had planned to ride out the storm in his home in Hampstead, North Carolina, but reconsidered due to its ferocity. Its wind speeds have dropped from a high of 140 miles per hour (225 kph) to 110 miles per hour (175 kph), reducing it from a Category 4 storm to a Category 2, and additional fluctuations and weakening were likely as it swirled toward land.