More than a million people are expected to flee low-lying areas, as SC and Virginia ordered mandatory evacuations of coastal areas starting on Tuesday.
"It's really hard to speculate this far out, since there's still significant uncertainty in the track", Sara Orsi, spokeswoman for flight-tracking service FlightAware, said about how Florence might impact flights after landfall. It may move a little north into Virginia or a little south into SC.
While the military has moved 30 Navy ships based in Norfolk, Virginia, including the aircraft carriers USS George H.W. Bush and USS Abraham Lincoln, nearly 1,000 National Guard troops have been activated in North and SC to help with any possible hurricane-related problems.
Millions are being told to evacuate as the North and SC coasts prepares for the arrival of Hurricane Florence, a Category 4 storm that continues to strengthen into "an extremely unsafe major hurricane through Thursday night".
McMaster said the state will reverse lanes on four main roads - so that all lanes are leading away from the coast - to facilitate the evacuation. While the damage at landfall was catastrophic, most of the deaths and damage from Harvey were from the tremendous, record-shattering rain that fell across the Houston metro area, which caused disastrous flooding.
Name SearchWatch Service' Henry McMaster also suspended his campaign and asked President Donald Trump for a federal emergency declaration.
"This is a multi-day event", Heden said. Justin Kibbey also recalled the distinctness of the storm's eye. And in Virginia, No. 13 Virginia Tech hosts East Carolina - which has already called off classes for the rest of the week as of Tuesday afternoon - while Virginia hosts OH in afternoon games.
Classified as a Category 4 on the five-step Saffir-Simpson scale of hurricane strength, Florence was the most severe storm to threaten the US mainland this year and the first of its magnitude to target the Carolinas since 1989, when Hurricane Hugo barreled over Charleston, South Carolina.
Florence is expected to remain a Category 4 storm when it makes landfall.
Several universities in the Cape Fear region are letting their students go home, and school systems are considering canceling classes later this week as a major hurricane approaches.
"We do not want to risk one SC life in this hurricane", the governor told reporters.
Helene - 490km west of the Cape Verde islands off the African coast - has winds up to 150km/h and is expected to continue moving west-northwest for another couple of days, the NHC said in its bulletin.
Hurricane Florence is seen from the International Space Station as it churns in the Atlantic Ocean towards the east coast of the United States, September 10, 2018.
Florence could hit the Carolinas harder than any hurricane since Hazel packed 130 miles per hour (209 kph) winds in 1954.
The first effects of what forecasters are already calling a large and extremely risky hurricane were already being seen on barrier islands Monday as unsafe rip currents and seawater flowed over the state highway.
Airlines, including American and Southwest, have started letting passengers change travel plans that take them into the hurricane's possible path.
Lining up behind Florence, Isaac was about 1,150 miles east of the Windward Islands with top winds of 75 mph early Monday, accelerating on a path to cross into the lower Caribbean Thursday as a weak hurricane.