"Further strengthening is anticipated, and Florence is expected to be an extremely unsafe major hurricane through Thursday", the National Hurricane Center said.
Its center will move between Bermuda and the Bahamas on Tuesday and Wednesday and approach the coast of SC or North Carolina on Thursday, the National Hurricane Center said.
Hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 115 miles (185 km).
The storm is expected to become a Category 4 hurricane very soon, with the National Hurricane Center forecasting maximum sustained winds of 150 miles per hour.
"Everyone in North Carolina needs to keep a close eye on Florence and take steps now to get ready for impacts later this week", Cooper said.
U.S. east coast is bracing for Hurricane Florence.
"These swells are likely to cause life-threatening surf and rip currents", the National Hurricane Center said. The hurricane center announced the change in an update, citing data from a NOAA Hurricane Hunter aircraft that showed Florence was rapidly intensifying, with maximum sustained winds near 130 miles per hour.
Hurricane Helene will likely continue to strengthen since it is in a low wind shear environment and warm waters.
The largest U.S. Marine Corps base on the East Coast, Camp Lejeune and its extensive beachfront northeast of Wilmington, North Carolina, lie within the NHC's forecast "cone" for possible landfall.
With September fulfilling the promises of peak hurricane season, residents are reminded to take the appropriate precautions for hurricane season - such as having emergency kits ready and knowing your hurricane plan - even if the storms are not now projected to hit Northwest Florida.
Hogan says the declaration of emergency is a planning measure to ensure all necessary resources are mobilized in areas of the state with greatest potential need.
The hurricane's path was still far from certain this morning.
Although it is quite a distance away, swells generated by Florence will begin to impact the southeastern USA, including Florida, today and through much of next week. Tuesday morning's data from hurricane-hunting aircraft supports this forecast, the center said.
- The tropics are very active this Monday, as three hurricanes are present in the Atlantic.
"I don't think many of us have ever been through a Category 4". But experts are urging people along the eastern seaboard to be especially cautious.