Sand Pedro Sula, Honduras ? Hurricane Wilma whirled into the record books as the 12th such storm of the season, strengthening early Wednesday into a Category 4 storm and setting a course to sideswipe Central America and Mexico. Forecasters warned of a “significant threat” to Florida by the weekend.

Wilma grew into a dangerous Category 4 hurricane with maximum sustained winds of 150 mph. It was only Tuesday morning that Wilma grew from a tropical storm into a weak hurricane, with 80 mph winds.

The storm could become a Category 5 sometime today, the National Hurricane Center in Miami said.

Forecasters warned that Wilma was likely to rake Honduras and the Cayman Islands before turning toward the narrow Yucatan Channel between Cuba and Mexico’s Cancun region – then move into the storm-weary Gulf.

The hurricane’s outer bands brought rain, high winds and heavy surf to the Atlantic coasts of Nicaragua and Honduras, which closed two seaports on its Caribbean coast.

By midnight, the hurricane was centered about 175 miles southwest of Grand Cayman Island and about 400 miles southeast of Cozumel, Mexico. It was moving toward the west-northwest at nearly 8 mph, according to the Hurricane Center.

“It does look like it poses a significant threat to Florida by the weekend. Of course, these are four- and five-day forecasts, so things can change,” said Dan Brown, a meteorologist at the U.S. National Hurricane Center.

Wilma already had been blamed for one death in Jamaica as a tropical depression Sunday. It has flooded several low-lying communities and triggered mudslides that blocked roads and damaged several homes, said Barbara Carby, head of Jamaica’s emergency management office. She said that some 250 people were in shelters throughout the island.

While some Florida residents started preparing by buying water, canned food and other supplies, hurricane shutters hadn’t gone up yet in Punta Gorda, on Florida’s Gulf coast, and no long lines had formed for supplies or gas.

The storm is the record-tying 12th hurricane of the season, the same number reached in 1969; 12 is the most in one season since record-keeping began in 1851.

On Monday, Wilma became the Atlantic hurricane season’s 21st named storm, tying the record set in 1933 and exhausting the list of names for this year.

The deadly season has already witnessed the devastation of Katrina and Rita in the past two months, which killed more than 1,200 people and caused billions of dollars in damage.

Honduras and its neighbors already are recovering from flooding and mudslides caused earlier this month from storms related to Hurricane Stan. At least 796 people were killed, most of them in Guatemala, with many more still missing.

The government of flood-prone Honduras warned that Hurricane Wilma posed “an imminent threat to life and property of the people of the Atlantic coast.” Neighboring Nicaragua also declared an alert.

Authorities in the Cayman Islands earlier called a hurricane alert.

Forecasters said Wilma should avoid the central U.S. Gulf coast that was devastated by Katrina and Rita. “There’s no scenario now that takes it toward Louisiana or Mississippi, but that could change,” said Max Mayfield, director of the National Hurricane Center.