seen there in decades. Many filled sandbags and boarded up homes and lined up to buy gas and groceries before leaving town.

"We're looking at a significant storm with significant impact, possibly greater than I've seen in my 59 years of life," Johnson said of his city on the shore of Apalachicola Bay, which where about 90% of Florida's oysters are harvested.

There will be no shelters open in Wakulla County, the sheriff's office warned on Facebook, because they are rated safe only for hurricanes with top sustained winds below 178km/h. With Michael's winds projected to be even stronger, residents were urged to evacuate inland.

"This storm has the potential to be a historic storm, please take heed," the sheriff's office said in the post.

Neighbors in Alabama - the entire stateis under an emergency declaration - also were bracing. Alabama Gov. Kay Ivey said she fears widespread power outages and other problems would follow. Forecasters also warned spinoff tornadoes would also be a threat.

With the storm next entering the eastern part of the Gulf of Mexico, which has warm water and favorable atmospheric conditions, "there is a real possibility that Michael will strengthen to a major hurricane before landfall," Robbie Berg, a hurricane specialist at the Miami-based storm forecasting hub, wrote in an advisory.

A large mound of sand in Tallahassee was whittled down to a small pile within hours on Monday as residents filled sandbags against potential flooding.

Tallahassee Mayor Andrew Gillum, Florida's Democratic nominee for governor, filled sandbags with residents and urged residents of the state capital city