Hurricane Michael isn't expected to hit Manatee County directly, but it will bring some wet weather.
As of 8 a.m., Michael was a Category 4 storm with winds of 145 miles per hour, the National Hurricane Center in Miami reported.
At 5 a.m., the centre of the hurricane was bearing down on a stretch of the Florida Panhandle, still about 140 miles (225 kilometres) from Panama City and 130 miles (209 kilometres) from Apalachicola, but moving relatively fast at 13 mph (21 kph).
In the storm-weary Carolinas, Hurricane Michael's approach is stoking fresh fears among homeowners who still have tarps on their roofs or industrial dehumidifiers drying their floors from destruction left by Hurricane Florence.
"The time to prepare is now". Forecaster have warned that parts of Florida's Big Bend area could see up to 12 feet of storm surge, while Michael also could dump up to a foot of rain over some Panhandle communities as it moves inland.
Mandatory evacuation orders went into effect in Bay County for people in Panama City Beach and other low-lying areas in the bull's-eye.More news: Liverpool and United in transfer fight for Ramsey
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Governor Scott called for coastal residents to evacuate, saying: "It could be the difference between life and death".
As Hurricane Michael closed in on Florida's Panhandle - threatening to become the strongest storm ever to hit the region - Gov. Rick Scott and emergency officials pleaded with residents in evacuation zones to flee before the killer storm arrived.
While most homes around him are vacation rentals or summer getaways for their owners, Sadousky had stayed put through more than four decades of storms. "That's going to mean you're gonna get flooding".
Drawing energy from the warm waters of the Gulf of Mexico, the storm strengthened rapidly into a potentially devastating Category 3 by evening.
Forecasters say some regions of the USA may see 12in (30cm) of rain, and storm surges of up to 12ft (3.6m).
Tallahassee Mayor Andrew Gillum, Florida's Democratic nominee for governor, helped people fill sandbags.