"And that will produce a lot of damage as well as prolong the beach erosion". "Get prepared on the East Coast, this is a no-kidding nightmare coming for you".
A hurricane's numerical classification tends to dominate the headlines, but it tells only part of the story - it rates a storm's wind speeds - and not necessarily the most life-threatening part. On top of that, a disastrous amount of rain - 500mm, possibly even as much as 1m - is expected to fall.
Federal Emergency Management Agency (Fema) spokesman Jeff Byard said storm surges may bring catastrophic flooding to inland areas. All that said, a saturated ground, even with tropical storm-force winds, will uproot trees.
In Wilmington, resident Michael Wilson fortified his home against the wind and rain, and anxious.
Isaac became the fifth hurricane of the season late Sunday and was initially expected to strengthen, potentially becoming a Cat 2 storm with 100 miles per hour winds, as it crossed warm ocean waters. Water kills more people in hurricanes than wind, and he said it will still be an extremely unsafe storm for rain and storm surge.
Florence's eye could come ashore early Friday around the North Carolina-South Carolina line. "Don't plan to leave once the winds and rains start".
The Outer Banks, Wilmington and other coastal cities were already experiencing strong winds and rain midday Thursday. The storm's 12-mph forward speed Thursday morning was a marked drop from Wednesday's 17-mph speeds.
Florence is a large storm packing hurricane-force winds that extend about 130 km outward from its centre; tropical storm-force winds extend even further, up to 315 km away.
Media captionWhy do people ignore hurricane warnings? Forecasters also were tracking two other disturbances. 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.
Because landfalling hurricanes commonly spawn twisters, a tornado watch was issued for eastern North Carolina.
As millions of people in the Carolinas and Virginia prepare for what could be historic damage from Hurricane Florence, people in space are keeping an eye on it from above. The trend is "exceptionally bad news", said University of Miami hurricane researcher Brian McNoldy, since it "smears a landfall out over hundreds of miles of coastline, most notably the storm surge".
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. His remarks fell flat in Puerto Rico where islanders are continuing to struggle to recover a year after the Category 4 storm.
The latest storm surge has some areas under over 8 feet of water.
Emergency declarations were in force in Georgia, South and North Carolina, Virginia, Maryland and the District of Columbia. Practically, however, that won't matter when it comes to storm surge and inland rainfall.
The Hurricane Florence has began to unleash fierce rains across the United States southeast.
Richard "Squirrel" Cook, who lives right off the ocean in Myrtle Beach, South Carolina, is not obeying Gov. Henry McMaster's mandatory evacuation order. And newly formed Subtropical Storm Joyce is not expected to threaten land soon.