Associated Press
Andrew Cardwell of Pirate Scooter Rentals leaves a gas station with full gasoline cans Saturday in Key West, Fla. in preparation for Tropical Storm Fay. Forecasters warned that Fay could bring hurricane-force winds to the Florida Keys as soon as Monday. Fay could hit as a Category 1 or 2 hurricane, with winds perhaps reaching more than 100 mph, forecasters said Saturday, stressing that it was too early to tell how intense the storm would become.

KEY WEST, Fla. (AP) — A light stream of traffic headed out of Key West Sunday as officials urged visitors to leave the string of low-lying islands ahead of Tropical Storm Fay, which forecasters said could strengthen to a hurricane.

Fay could start pelting parts of the Keys and South Florida late Monday or early Tuesday as a strong tropical storm or minimal hurricane. Keys officials issued a mandatory evacuation order for visitors starting at 8 a.m. Sunday and asked those who had not yet arrived to postpone their trips.

"We hate to inconvenience those visitors that had plans to be in the Keys the next few days, but their well-being is our top priority," said Monroe County Mayor Mario Di Gennaro, chairman of the Keys tourist development council.

Officials said hotels and businesses won't be forced to remove visitors, but should use common sense. They also said schools in the Keys will be closed Monday and Tuesday.

With the warnings, some Key West businesses began putting up hurricane shutters, but tourists and residents still strolled lazily through downtown, having coffee and eating breakfast.

"We've been living in Florida now for 10 years, so we need to get some stuff together, but we're not going to rush out of here," John Civette said as he strolled the shop-lined streets with his wife, Tonya.

Civette said they would cut their vacation short and head home to the southwest Florida city of Bonita Springs to prepare their home for the storm.

Paul and Sandy Dunko, of Naples, Fla., were having breakfast with their family Sunday morning before heading home to secure their boat and put up their hurricane shutters. Fay could reach that area late Monday or early Tuesday.

"We've got to get back and buckle up our own house," Paul Dunko said. "We're hoping the traffic won't be too horrible."

The sixth storm of the 2008 Atlantic season picked up some momentum early Sunday morning as it headed toward Cuba, and could be a hurricane by the time it reaches the island's center, forecasters said. At 11 a.m. EDT Sunday, Fay's center was located about 350 miles southeast of Key West and moving west-northwest at nearly 13 miles per hour. The storm had maximum sustained winds near 50 mph with some gusting.

Flooding from Fay killed four people Saturday in the Dominican Republic and Haiti.

Landfall could potentially be late Tuesday or early Wednesday and it could be anywhere from the western coast to the southwestern coast of Florida, hurricane center meteorologist Chris Sisko said.

Sisko said Fay's track is similar to 2004's Hurricane Charley, a much stronger Category 4 storm.

Florida Gov. Charlie Crist declared a state of emergency Saturday as officials in Tallahassee opened their emergency operations center.

A tropical storm warning and a hurricane watch were in effect from Craig Key westward to the Dry Tortugas.

A hurricane watch means hurricane conditions are possible, generally within 36 hours. A tropical storm warning means tropical storm conditions are expected within 24 hours. Forecasters said they issued both for some parts of Florida because they're not yet sure how much Fay will strengthen.

A hurricane watch was in effect for the remainder of the Keys and on the Florida west coast south of Anna Maria Island, just south of the Tampa Bay area. A tropical storm watch was also in effect for the southeast coast of Florida from Ocean Reef north to Jupiter Inlet, as well as for Lake Okeechobee.

Keys emergency officials often take the precaution of ordering early evacuations when a storm threatens because traffic can back up for miles on the single highway to Florida's mainland.

Besides the threat of damage from high winds, most of the islands sit at sea level and could be flooded by Fay's storm surge.

Keys officials encouraged people who live in low-lying areas, in mobile homes and on boats to evacuate and said four shelters would open at 7 p.m. Sunday.

Key West was last seriously affected by a hurricane in 2005 when Wilma, a Category 3 storm, sped past. The town, especially the tourist district, escaped widespread wind damage, but a storm surge left hundreds of homes and some businesses flooded. The deadliest storm to hit the island was a Category 4 hurricane in 1919 that killed up to 900 people there and elsewhere, many of them offshore on ships that sunk.

The Category 5 Labor Day Hurricane of 1935 passed over the middle Keys with estimated wind gusts of 150 to 200 mph. It killed more than 400 people, more than half of them World War I veterans living in rehabilitation camps.