Hurricane Irma has strengthened into a Category 5 storm as it roared toward the northeast Caribbean on a path toward the U.S.
Irma's maximum sustained winds increased to 185 mph Tuesday. It was centered about more than 200 miles east of Antigua and moving west at 14 mph.
Antigua's airport closed with an ominous statement from local authorities as Hurricane Irma approaches the Caribbean island.
The statement from the V.C. Bird International Airport says it is shutting down Tuesday and advises all visitors and residents of the two-island nation of Antigua and Barbuda to seek protection from the "onslaught" of the Category 5 storm.
It closes with: "May God protect us all."
The center of the storm was expected to start passing north of Antigua and near or over Barbuda on Tuesday night.
Officials in the Florida Keys are gearing up to get tourists and residents out of the possible path of the storm.
Monroe County spokeswoman Cammy Clark says in a news release that a mandatory evacuation for tourists will begin at sunrise Wednesday. An evacuation plan for residents is also under way but a timetable hasn't been determined.
Clark says government offices, parks and schools will close and there will be no shelters in Monroe County. The county's three hospitals are also beginning evacuation plans.
U.S. 1 is the only route in and out of the island chain off the southern peninsula of Florida.
Clark says residents and tourists should begin filling their tanks with fuel to prepare to drive to the mainland.
Florida Gov. Rick Scott is activating 100 members of the Florida National Guard to prepare for the hurricane.
Scott says in a statement that the initial 100 troops will be stationed throughout the state. Some 7,000 National Guard members will report to duty Friday, when the storm could be bearing down on Florida.
Scott said Tuesday that the exact path of the storm is still unknown but officials "must prepare for the worst."
On Monday he declared a state of emergency in all of Florida's 67 counties.
Two hurricanes hit the state last year but neither was as powerful as Category 5 Irma is right now.
Meanwhile, Tropical Storm Jose has formed in the open Atlantic far from land.
Jose is located to the east of Hurricane Irma.
Jose is the 10th tropical storm of the season. It has maximum sustained winds of 40 mph and is about 1505 miles east of the Lesser Antilles.
Floridians took advantage of the Labor Day holiday to empty many store shelves of drinking water and other supplies in advance of Hurricane Irma.
By mid-day Monday, many grocery stores across South Florida had been emptied of bottled water.
Senior forecaster Richard Pasch, at the National Hurricane Center, says it's too soon to say if Hurricane Irma will strike the U.S. mainland.
“Some of our more reliable models of showing a track over Florida with some uncertainty,” Pasch said. “You know we have some models we run that show quite a bit of spread. You know we could be off by a couple of hundred miles so I don’t want to be more specific than that.”