The center is located right along the Florida and Georgia line and is forecast to track northwest and remain a tropical storm through this evening, then weaken to a tropical depression through Tuesday morning as it tracks across central Alabama.
Florida emergency management director Bryan Koon said officials would wait until first light on Monday to begin rescue efforts and assess damage.
Midnight: The center of Hurricane Irma moved 25 miles south of Lakeland by midnight with 100 mph top winds, but it sent relentless gusts and rain for more than 400 miles from its center and refused to go quietly across South Florida including Palm Beach County.
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"It will be just rain showers, and we won't have any wind", said Aaron Tyburski, meteorologist with the National Weather Service in State College.
Irma hit Miami with 209kph winds and is now heading towards the Tampa Bay area on Florida's west coast, where almost 455,000 residents are preparing for impact.
That would have put the hurricane over the east coast of Florida.
President Donald Trump has vowed a full response to Irma and continued federal support for victims of Hurricane Harvey, which flooded Texas. "We're going down to the Keys to try to make sure the roads are passable, makes sure the bridges are safe".
Miami airport's difficulties add to the transportation chaos Irma has inflicted on Florida residents. "We asked citizens who wanted to stay to let us know their physical addresses, so that we could check on them post storm", Honig said.
Irma was still working its way up the state late Sunday, battering major airports in Orlando, Tampa and Jacksonville with hurricane force winds.
Irma was churning toward the heavily populated Tampa Bay region, a zone seen as particularly susceptible to storm surges due to its geographical position and sloping land off the coast.
"I will tell you in no uncertain terms - and I am not going to sugarcoat it - this is going to be a hard storm", Buckhorn said at the news conference.
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