Reports from an Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds have increased to near 140 miles per hour (225 kph) with higher gusts. Many shallowly rooted trees will be snapped or uprooted and block numerous roads.
But it isn't done yet.
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).
Florida Gov. Rick Scott warned it was a "monstrous hurricane", and his Democratic opponent for the Senate, Sen.
It could be the strongest hurricane to hit the Florida panhandle in recorded history.
"The time to prepare is now".
Forecasters said parts of the Panhandle and Florida's marshy, lightly populated Big Bend area - the crook of Florida's elbow - could see 9 to 13 feet (2.7 to 4 meters) of storm surge.
Mandatory evacuation orders went into effect in Panama City Beach and other low-lying areas in the storm's path.
Michael threatens to become the most the most intense hurricane to hit the Florida panhandle since 1851, according to Philip Klotzbach, a meteorologist at Colorado State University.
Accuweather captured this image of Hurricane Michael that looks like a skull.
"People need to start leaving now", sheriff Tommy Ford told an emergency meeting Monday night, according to the AP.
Forecasters say some regions of the United States may see 12in (30cm) of rain, and storm surges of up to 12ft (3.6m). He added that people will "not be dragged out of their homes", but if they choose to stay they will be doing so at their own peril. "It's too late to get out, you need to hunker down".
Tallahassee Mayor Andrew Gillum, Florida's Democratic nominee for governor, helped people fill sandbags. "There's nothing between us and this storm but warm water' and I think that's what terrifies us about the potential impacts".