The biggest danger, as forecasters saw it, was not the wind but the water: the storm surge along the coastline and the prospect of 300 to 1000mm of rain over the next several days that could trigger catastrophic flooding in a slow-motion disaster well inland.
Top winds were holding at 90 miles per hour - that's just a Category 1 hurricane - but some communities were already submerged in more than six feet of water as the storm drenched the coast. "It's an uninvited brute who doesn't want to leave".
"We know we're in for a long haul here", Cooper said of predictions that the storm will linger over the area. "But I think we're ready".
Once a Category-4 hurricane with winds of 225kph, the hurricane was downgraded to Category 1 on Thursday night.
Hurricane-force winds extended 130km from its centre, and tropical storm-force winds reached out to 315km.
As of 1 p.m. ET, more than a foot of rain had fallen in many towns in southeastern North Carolina. Florence dumped more than 20 inches on Oriental, N.C., the NHC said. But with a storm surge putting pressure on water to head back inland and heavy rains swelling those rivers, widespread flooding is the result. "We have two boats and all our worldly possessions", said Susan Patchkofsky, who refused her family's pleas to evacuate and stayed at Emerald Isle with her husband.More news: Wind approaches outer banks of North Carolina
More than 440,000 homes and businesses were without power in North and SC early on Friday, utility officials said.
The No. 1 mission right now, Cooper said, is to save lives.
On the mainland in New Bern, authorities said more than 100 people had to be saved from floods and that the downtown area was underwater.
Emergency Management services in North Carolina are reporting that 497,255 customers are without power in North Carolina as Hurricane Florence makes landfall. The homes of about 10 million were under watches or warnings for the hurricane or tropical storm conditions.
Still, some residents ignored calls to evacuate.
As the Category 1 hurricane bore down on the Carolinas on Thursday, WCTI meteorologists Donnie Cox and Shane Hinton continued to oversee coverage of the storm for the city of New Bern. The agency adds that people trapped by flooding should "never enter attics or crawl spaces".More news: Exodus grows as motorists flee from 'big and vicious' Hurricane Florence
The Wilmington airport had a wind gust clocked at 169 km/hr the highest since Hurricane Helene in 1958.
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Florence arrived at the Carolina coast as a Category 1 storm, with winds far slower than the fearsome 150 miles per hour of just a few days ago.
It was expected to begin pushing its way westward across SC later in the day, in a watery siege that could go on all weekend. But he expected to be able to ride the storm out.
Coastal towns in the Carolinas were largely empty, and schools and businesses closed as far south as Georgia. Thousands of soldiers from their National Guard forces have been mobilized.More news: New Super Mario Bros. U Deluxe Comes to Switch in Early 2019