"It's getting late to evacuate", said South Carolina Governor Henry McMaster.
"It's going to be bad", said Woody White, chairman of the New Hanover County Commissioners. Masters estimated that storm surge caused at least $3 billion in damage, compared with maybe $1 billion for wind damage.
Hurricane Florence will be one of the biggest storms to make landfall along the USA eastern seaboard in decades. That makes sense since the category of a storm is generally determined by its maximum sustained winds; but, researchers have found, the vast majority of deaths (nearly 90%) from hurricanes, tropical storms, or tropical depressions between 1963 and 2012 were attributable to "storm surge, rainfall flooding, high surf, and deaths just offshore".
The coastal surge from Florence could leave the eastern tip of North Carolina under more than 9ft of water in spots, projections showed.
"I ask all Georgians to join me in praying for the safety of our people and all those in the path of Hurricane Florence", Mr Deal said.
"I don't care if this goes down to a Category 1".
At 11:00 am (1600 GMT), the eye of the storm was about 485 miles (785 kms) southeast of Wilmington, North Carolina, moving in a northwest direction at 15 mph (24 kph).
Even if Hurricane Florence's category weakens, or if the storm no longer maintains its hurricane status, the amount of rain can still be biblical.More news: Flu vaccine clinics in South Lake Tahoe and West Slope
The hurricane centre also said the threat of tornadoes was increasing as the storm neared shore.
The administration said that as Florence, a Category 2 storm, is expected to make landfall in the US southeast coast on Friday, the massive storm will obstruct electricity transmission and distribution, while widespread evacuations and disruptions to normal business operations could impact demand patterns for transportation fuels.
"This rainfall will produce catastrophic flash flooding and prolonged significant river flooding", the NHC said.
The NHC said Helene was weakening, however, and posed no danger to land. "Inland flooding kills a lot of people, unfortunately, and that's what we're about to see", he said.
Hurricane Florence's outer edges have started to batter the coast of North Carolina - with winds of 100mph bending trees and shooting frothy seawater onto the streets.
Roy Cooper urged residents in evacuation areas of his state to get out while they still can.
Schools and businesses closed as far south as Georgia, airlines canceled more than 1,500 flights, and coastal towns in the Carolinas were largely emptied out.
President Donald Trump declared states of emergency for North and SC and Virginia, opening the way for federal aid.More news: Digger: Klopp doesn't need silverware this season
Duke Energy said Florence could knock out electricity to three-quarters of its four million customers in the Carolinas, and outages could last for weeks.
Mr Cooper's office said the current emergency declaration was helping state officials prepare for the storm. "The infrastructure is going to break, the power is going to go out".
Numerous communities throughout the region have issued either mandatory or voluntary evacuation orders.
"Think of it like a marathon", said Mark Robinson, from The Weather Network, also in Wilmington with Kourounis.
"Against my better judgment, due to emotionalism, I evacuated", said Fisher, 74. "We'll handle it. We're ready, we're able".
"It doesn't matter how much money you have or how many generators you have if you can't get gas", she said.
Avair Vereen, 39, took her seven children to a shelter in Conway High School. "We just need to figure out how to make it through".
"If we lose the house, oh well, we can get housing".More news: Trump's Supreme Court nominee on track as Senate hearing ends
- Jeff Bezos launches $2-billion fund to help homeless families, build preschools
- 2 more U.S. service members’ remains ID’ed in North Korea handover
- EPL: Arsenal provides latest injury updates ahead of Newcastle clash
- Ray Allen pays tribute to Reggie Miller in Hall of Fame speech
- Tottenham Hotspur without Dele Alli and Hugo Lloris against Liverpool
- Everything you need to know about Hurricane Florence
- Russian bombers intercepted by USA fighter jets west of Alaska
- Apple iPhone XR - Hands On
- Barrow sends special delegation to Kofi Annan's funeral
- Pound rises on Barnier’s Brexit comments ZlotoNews