Georgia joined North and South Carolina, Virginia and Maryland in issuing an emergency declaration as forecasts showed Florence dumping historic amounts of rain - potentially 37 trillion litres - on the southern states. Forecasters warned as the storm continues to widen - and it is likely to linger along the coast for days - the hurricane will bring seawater surging onto land along with torrential downpours. Federal emergency management officials warned that Florence - while weakening slightly - remains a "very risky storm" capable of wreaking havoc along a wide swathe of the coast.
But despite the drop in wind strength, the most risky threat comes from Florence's rains and storm surge, which could bring flooding far inland. "We know that this is an extremely risky situation", Cooper told "CBS This Morning" on Thursday.
As of 11 p.m., Florence was centred about 85 miles (135 kilometres) east-southeast of Wilmington, its forward movement slowed to 5 mph (7 kph). As the storm moves inland it will find a relatively flat area for hundreds of miles. And Florence's large wind field will add to the perils as the storm grinds over beaches and inland.
"I don't care if this goes down to a Category 1", CNN meteorologist Chad Myers said. "So instead of maybe 120 mph winds for 30 minutes, you might end up with 90-100 mph winds for a couple of hours, or three or four hours".
Myrtle Beach, a SC beach resort, was virtually deserted with empty streets, boarded up storefronts and very little traffic.
Should Florence bring much rain, either over the weekend or next week, the region is already prone to flooding, said Jay Ringgold, Baltimore County's director of homeland security and emergency management. Hundreds of thousands of people have already evacuated. He also urged those outside of the evacuation zones to be prepared.
"Do not focus on the wind speed category of #Hurricane #Florence!" the National Hurricane Center said Thursday morning. "Life-threatening storm surge flooding, catastrophic flash flooding and prolonged significant river flooding are still expected".
Even if you know nothing about hurricanes, an unavoidable sense of doom and destruction overtakes you when you look at this image of Hurricane Florence as it moves inexorably toward North and SC.
Image: Waters come ashore in Avon, North Carolina.
Up to 10 inches of rain is predicted as far west from the Atlantic Ocean as Charlotte, N.C., the NHC's Ken Graham said Thursday. That forecast area also includes part of southwest Virginia.
Florence is projecting hurricane-force winds outward up to 80 miles from its center; tropical-storm-force winds are swirling outward up to 195 miles away.
- Hurricane Florence remains a Category 2 storm as it makes its approaches to the Carolinas. Many shallowly rooted trees will be snapped or uprooted and block numerous roads.
Several million people could lose power by the time Florence sloshes its way through the state.