A watch from Deerfield Beach southward on the east coast and from Chokoloskee southward on the west coast was issued at 5 a.m., meaning hurricane conditions of at least 74 mph are possible within 36 hours. The Keys were put under a watch on Sunday afternoon.
Gov. Jeb Bush issued a state of emergency Sunday for all of Florida, because forecasters said Ernesto could potentially threaten a large swath of the state by late in the week. Immediate concern, though, centered on the Keys, where visitors were ordered out and plans were enacted to evacuate special-needs residents to Miami.
In the Keys, three shelters were set to open Monday. All travel trailers and recreational vehicles were ordered out of the Keys, and mobile home residents were also urged to evacuate.
Some residents of the low-lying island chain flocked to grocery stores and home-supply warehouses to stock up on canned goods, bottled water and other storm essentials.
"Key Westerners are used to this," said Jim Bernard, assistant manager at a Home Depot in Key West.
At 5 a.m., the fifth named storm of the Atlantic hurricane season had top sustained winds of 50 mph, down from 75 mph Sunday, according to the National Hurricane Center. It was centered 45 miles south-southeast of Guantanamo, Cuba, and about 600 miles from the middle and lower Keys. It was moving northwest at 12 mph.
Ernesto was 1 mph above the threshhold to be a hurricane Sunday, but weakened as it plodded toward Cuba's southeastern corner. Still, the hurricane center cautioned that Ernesto may strengthen significantly as it moves toward Florida.
"I don't want anyone to overly focus on the downgrading. ... It has a good chance to regain hurricane status," said Max Mayfield, director of the National Hurricane Center.
The state of emergency directs counties to activate their emergency management offices and activates the National Guard, among other things. Bush canceled several meetings scheduled in New York Monday, and will remain in Tallahassee to monitor storm developments.
Ernesto lashed Haiti and the Dominican Republic with heavy rain Sunday and threatened to bring as much as 20 inches of rain to parts of Haiti, prompting fears of mudslides and flooding. The storm was expected to move over Cuba, then bring rain and wind toward Florida, forecasters said.
"You don't know where to go. You don't know where it's going to blow," said tourist Jim Rogers of Lodi, N.J., who spent Sunday preparing to leave the Keys. "You don't want to be in Key West."
Florida's emergency management center in Tallahassee was partially activated Sunday, and several counties around the state were expected to follow suit Monday. Emergency officials encouraged people across the state to monitor the storm, check emergency supplies and disaster plans — a familiar theme, considering seven hurricanes have hit Florida and one has brushed by in the past two years.
"Ernesto bears watching," said Mike Stone, spokesman for the Florida Division of Emergency Management.