The storm made landfall as a powerful Category 4, the second highest rating on the Saffir-Sampson wind scale, and strike a stretch of the state's north-western coastline known as the Florida Panhandle.
A Hurricane Warning is still in place in coastal Bay County, Florida. Some 125,000 homes were left without power in Georgia and over 52,000 homes in Alabama as of Wednesday evening.
The latest update from the NHC cites still Category 3 sustained winds and at this time hurricane Michael is moving towards Georgia, which is unusual but due to the late intensification and fast movement of the storm not entirely unexpected.
"I've had to take antacids I'm so sick to my stomach today because of this impending catastrophe", National Hurricane Center scientist Eric Blake tweeted as the storm - drawing energy from the unusually warm, 84-degree Gulf waters - became more menacing.
The Gadsden County Sheriff's office said that a man was found dead in his home in a small town outside of Tallahassee after a tree crashed through the roof. Those winds are expected to arrive between noon and 3 p.m. and will continue until 6 a.m. Thursday.
In St. Marks, John Hargan and his family gathered up their pets and moved to a raised building constructed to withstand a Category 5 after water from the St. Marks River began surrounding their home.
About 30km south of Mexico Beach, floodwaters were more than 2.3m deep near Apalachicola, a town of about 2,300 residents, hurricane center chief Ken Graham said.
Gov. Nathan Deal of Georgia issued an emergency declaration for 92 counties in the southern part of that state.
Michael is making its way northeast toward Georgia and the Carolinas at about 14 miles per hour (22.5 km/h).
The Carolinas are still reeling from severe flooding in the aftermath of Hurricane Florence less than a month ago.
Residents and tourists were told to flee low-lying areas in at least 22 counties along the shore in Florida's Panhandle and adjacent Big Bend region.
The wind and storm surge related insurance industry loss from hurricane Michael is estimated to be between $2 billion and $4.5 billion by Corelogic, based on a pre-landfall data assessment of the storms impacts to insured assets.
Michael's strong, well-developed core makes for a very powerful, windy storm on land.
Central pressure is the measure of how much the atmosphere in the middle of a storm weighs.
"Northwest Florida has never encountered a storm of this magnitude", Rogers said in a release. A pine tree punched a hole in their roof and his ears even popped when the barometric pressure went lower.
Sally Crown rode out Michael on the Florida Panhandle thinking at first that the worst damage was the many trees downed in her yard.
Only two other storms in recorded American weather history - that is, since 1851 - had stronger winds.
In Port St. Joe, two storm chasers had to abandon their vehicle and find shelter as over 100 miles per hour wind gusts and heavy rain made it impossible for them to drive.