"The worst of the storm is not yet here but these are early warnings of the days to come", he said. "Catastrophic effects will be felt". One moment, it's going to be real bad; next moment, it's slowing down.
Floods have already begun in some areas, and Florence is predicted to leave as many as three million people without power.
She said the momentum the storm has generated on its long trip across the Atlantic won't go away just "because the winds decrease a couple miles an hour".
Florence's maximum sustained winds were clocked on Thursday at 105 miles per hour (165 kph) after it was downgraded to a Category 2 on the five-step Saffir-Simpson scale, according to the NHC. The forecasters say the slow speed will give Florence time to pound the Carolinas with bands of heavy rain.
Coastal flooding is a major concern due to high storm surge and potentially 20 to 30 inches of rainfall through the weekend.
"I was feeling fine until I woke up this morning and this is a ghost town", said Kristin Beard, a 40-year-old Myrtle Beach marketer.
Horry County Police Chief Joseph Hill said those violating the curfew without a valid reason will be subject to arrest, and City of Myrtle Beach spokesman Mark Kruea said a curfew violation is a misdemeanor offense in the city.
Florence conitnues to slowly edge northwest towards southeastern North Carolina Thursday afternoon.
A buoy off the North Carolina coast recorded waves almost 30 feet (9 meters) high as Florence churned toward shore.
Now, many more people and houses are set to endure hurricane-force winds, which extend 80 miles out from Florence's center. We're going to find out unfortunately that the fresh water flooding issue is going to become a big part of this storm as it moves inland and spreads these record-setting rainfall amounts from the coast all the way into the Charlotte region.
"Remember, rivers continue flooding, even when the rain stops", he said. The Charleston area is under a storm surge watch.
"Your time is running out", he warned those who had not yet heeded the warning to evacuate. What have we seen so far from this storm on the coast?
An onlooker checks out the heavy surf at the Avalon Fishing Pier in Kill Devil Hills, North Carolina on Sep 13, 2018 as Hurricane Florence approaches the east coast.
The head of Duke Energy Corp.'s North Carolina operations says it could take weeks to restore electricity if the company's prediction that 1 million to 3 million of its 4 million customers lose power. Several residents fled the coast under both mandatory and voluntary evacuations.
"I'm not anxious at all", said Richard Ford, 34, smoking a cigarette outside one of Wilmington's five shelters.
Outside this zone of destructive winds, damaging winds are still likely, even some distance inland from the coast, which would lead to minor structural damage, downed trees and widespread power outages.
Not everybody was heeding orders to evacuate, however.
Officials in several states have declared states of emergency, including in the Carolinas, Georgia, Virginia and Maryland, where coastal areas are still recovering from summer storms.
"The shelters are not taking dogs", Ramirez said.