National Hurricane Center Director Ken Graham is warning that a Category 4 hurricane will bring catastrophic damage to Florida's Panhandle.
Graham says Michael's top winds of 145 mph (230 kph) are powerful enough to peel off roofs and cause the "complete destruction of houses."
Stretches of the coast could see storm surge of at least 6 feet (2 meters), with waters rising in some places up to 14 feet (4 meters) above the ground. Graham wants people to think about how tall they are, and just how high that water can be.
Michael is powerful enough to remain a hurricane well inland as it travels over Georgia on Thursday. Graham says falling trees will pull down utility lines, leaving some areas without power for weeks, and hazardous conditions will persist long after the storm blows through.
He says the aftermath of a hurricane is "not the time to start learning to use that chain saw."