A Tropical Storm Watch has been issued from the Suwanee River to Anna Maria Island, including Tampa Bay.
Michael is 140 miles east-northeast of Cozumel, Mexico, moving toward the north near 7 mph as it moves into the southern Gulf of Mexico with 75 mph winds.
After hitting Florida, the storm is forecast to move north-east on Wednesday and Thursday along the Atlantic Coast and batter the Carolinas, which are still recovering from Hurricane Florence last month. But within a few hours it gained more strength and by Sunday evening, it had top sustained winds of 95 kph.
"Steady to rapid strengthening is forecast during the next day or so, and Michael is forecast to become a major hurricane by Tuesday or Tuesday night", the National Hurricane Center warned. The storm's tropical storm-force winds extended 175 miles from its center.
In fact, the situation is already looking so dire for a midweek landfall on the Florida panhandle that Governor Rick Scott has preemptively declared states of emergency in numerous counties while suspending his own Senate campaign to warn residents of impending danger.
In anticipation of travel impacts, Southwest has implemented a flexible rebooking policy for customers scheduled to fly to or from several cities in the storm's path this week, including New Orleans, Panama City, Florida and Pensacola, Florida Tuesday through Thursday.
Michael is forecasted to become a major hurricane by Tuesday or Tuesday night.
Tampa Bay has about a 40 percent chance of tropical storm-force winds within the next five days, according to the Weather Service.
Scott activated 500 National Guard troops in advance of the storm.
The tropical storm is expected to swell into a Category 1 hurricane as soon as Monday night as it rolls into the US Gulf of Mexico, with winds of 70 miles per hour, forecasters said. "Don't take a chance", he said. Today we're expecting very warm, muggy weather, however, Tuesday a strong cold front is going to approach us.
"We've seen this happen many times with storms, and they've just start to bring all that water with them", explained FOX 13's meteorologist Dave Osterberg, "and they've pushed that water in".
The latest track shows a weakening Michael moving either directly through, or at least near central Georgia as a tropical storm.