The cone, which represents the "probable track of the center of a tropical storm" is "formed by enclosing the area swept out by a set of circles along the forecast track (at 12, 24, 36 hours, etc)" the NHC says on its website.
A hurricane hunter plane found Florence strengthening quickly, reaching top winds of 85 miles per hour Sunday evening after crossing the 74 miles per hour threshold from tropical storm to a hurricane earlier in the day. "He also told us that he has requested, activated 200 National Guards with thousands more available should that be necessary".
Forecast models have said that several feet of heavy rain could cause flooding well inland from the coast. Tropical storms are defined as those of at least 39 miles per hour.
Category 4 hurricanes are unusual this far north. Hurricanes need warm water to thrive - and the sea surface temperature of ocean water cools as you get further away from the tropics.More news: Airlines Preparing for Impact of Hurricane Florence
"Large swells affecting Bermuda and portions of the US East Coast will continue this week". The entire coastlines of North and SC, in addition to some parts of southeastern Virginia, are under a mandatory evacuation plan.
Oosterwyk was gathering important papers including tax documents from her store on Monday, and said she planned to drive 240km (150 miles) inland to Cary to ride the storm out.
Cooper called the residents of his state "a hardy bunch" that have endured a multitude of past storms, but that "this storm is different". SC governor Henry McMaster also suspended his campaign and asked President Donald Trump for a federal emergency declaration.
"Interests elsewhere in the southeastern and mid-Atlantic states should monitor the progress of Florence". This will lead to widespread and unsafe flooding, inundation of roads and damaged infrastructure.
Historically, 90 per cent of fatalities from hurricanes, tropical storms and tropical depressions have been caused by water, said NHC spokesman Dennis Feltgen said.