As of late Tuesday, the storm was located about 200 miles south-southwest of Apalachicola, Fla., and 220 miles south-southwest of Panama City as it moved north at 12 mph.
Since the storm will spend two to three days over 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.
As of 5 a.m. ET on October 9, Michael's center was about 420 miles south of Panama City, Florida and 390 miles south of Apalachicola, Florida.
Hurricane Michael is intensifying now in the Gulf of Mexico, but its impact on eastern Virginia is still uncertain. Landfall is expected Wednesday on Florida's northeast Gulf Coast. Michael is now a strong category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale.
A hurricane warning was issued for much of the Florida panhandle, with tropical storm watches and warnings issued for areas nearby.
He noted that residents in the nearby coastal county of Wakulla were being forced to keep their shelters shut because they aren't built to withstand severe winds that may come with Hurricane Michael.
Now, battling wind shear but emerging in the Gulf of Mexico, it's a strengthening hurricane, with winds up to 110 miles per hour as of 11 a.m. Tuesday. The storm could inundate more than one-fourth of that coast's dunes, causing flooding behind the protective dune line, said Kara Doran, leader of the USGS Coastal Change Hazards Storm Team. Storm surge could reach a monstrous 12 feet in some areas - enough to "easily go over the roofs of some houses", he said. Residents in these areas should follow advice given by local officials, and keep tabs on live updates, which are available from CNN.
Relatively minor flooding from a combination of king tides and 1 to 3 feet of storm surge from Michael, with Tuesday night's tide expected to be the highest.
Alabama Gov. Kay Ivey declared a state of emergency for her state Tuesday because of expected wide-spread power outages and wind damage.
System Headed Toward The Northern Gulf
The potential storm does not yet have a predicted path, but NHS experts said they will be watching it carefully. As of Saturday night, the forecast looks like western Florida could see the most intense part of the storm.
FEMA administrator Brock Long said the agency was prepared for the storm in all the states likely to feel Michael's impact.
Tropical storm warnings are posted from the Alabama/Florida border westward to Alabama's border with MS, as well as from Suwannee River, Florida, to Chassahowitzka, Florida.
Alabama is under a state-wide state of emergency ahead of the hurricane, along with 92 counties in southern Georgia and 35 counties in Florida.
"For those considering evacuation, I can't stress strongly enough the importance of leaving as early as possible", Bay County Sheriff Tommy Ford said on Facebook.
The Florida Disaster website on October 9 said that parts or all of Bay County, Citrus County, Franklin County, Dixie County, Gulf County, Jackson County, Levy County, Okaloosa County, Taylor County, Wakulla County, and Walton County have been issued mandatory evacuation orders.
President Donald Trump on Tuesday approved a pre-landfall emergency declaration at the request of Florida Gov. Rick Scott.
"A hurricane warning has been issued for portions of the Florida Gulf Coast, and everyone in these areas should prepare for life-threatening winds associated with the core of Michael".
The neighbouring states of Alabama and Georgia have also declared a state of emergency.