Florence was downgraded to a Category 1 storm on the five-step Saffir-Simpson scale on Thursday evening and was located about 50 miles (80 kilometers) southwest of Morehead City, North Carolina with maximum sustained winds of 90 miles per hour (150 km/h).
Hurricane Florence is continuing to push towards a landfall around the North Carolina/South Carolina border, and is beginning to lash the central Atlantic seaboard with damaging winds and storm surge.
About 1.7 million people in North Carolina, South Carolina and Virginia have been put under voluntary or mandatory evacuation orders to avoid what emergency officials called a "once in a lifetime" storm.
More than one million people had been ordered to evacuate the coasts of North and SC and Virginia and thousands moved to emergency shelters, officials said.
The storm has sustained wind speeds of 90 miles per hour, and a total of 40 inches of rain could fall over the next few days, according to the National Hurricane Center.
Roy Cooper warned residents to not let their guard down ahead of Hurricane Florence's landfall later this week.
Winds bent trees toward the ground and raindrops flew sideways as Florence moved in for an extended stay, with enough of its killer winds swirling overseas to maintain its power. "Today the threat becomes a reality".
Don't relax, don't get complacent.
On social media, people caught in the storm are posting dramatic videos of flooding and high winds.
Isaac, which had built to tropical storm status when its winds topped 39 mph on Saturday, has weakened to a depression over the eastern Caribbean sea with winds of 35 mph and is moving west at 15 mph, lashing the Lesser Antilles with rain squalls as of the 5 a.m. advisory.
"The worst of the storm is not yet here but these are early warnings of the days to come", he said. "I am frightened about what's coming".
Its surge could cover all but a sliver of the Carolina coast under as much as 11 feet (3.4 meters) of ocean water, and days of downpours could unload more than 3 feet (0.9 meters) of rain, touching off severe flooding. The main highway in the Outer Banks was closed in parts as seawater pushed in.
Power suppliers report more than 350,000 outages in North Carolina, the bulk along the coast. "But we are going to do everything we can".
The result: prolonged storm surge, wind and rain.
The storm will be a test of President Donald Trump's administration less than two months before elections to determine control of Congress.
The hurricane was seen as a major test for the country's Federal Emergency Management Agency, which was heavily criticized as slow and unprepared for Hurricane Maria in Puerto Rico past year.
"Catastrophic freshwater flooding expected over portions of North and SC".
Almost 300,000 customers in North Carolina were meanwhile reported to be without power as the outer band of the storm approached.