After ratcheting up Tuesday night to become one of the most intense storms ever recorded over the Atlantic basin, Hurricane Wilma yesterday became even more troublesome by baffling forecasters trying to predict where it would make landfall.

The Category 5 storm was located 285 miles southeast of Cozumel, Mexico, yesterday evening, and was moving west-northwest about 7 miles per hour. A "consensus" forecast from the National Hurricane Center projected the storm would turn eastward and head across southern Florida over the weekend.

But Max Mayfield, director of the National Hurricane Center, emphasized that among the dozen or so models used to predict Wilma's path, there was wide disagreement.

Some models predicted the storm would stay far enough south that it would pose no threat to the United States.

There was a lot of "scatter" in the disparate forecasts, he said.

"This is one of those cases where we have a tremendous amount of uncertainty," Mayfield said. "Absolutely, people should not let their guard down."

Earlier in the day, emergency officials in the Florida Keys ordered the evacuation of visitors. Because the Keys are difficult to evacuate, tourists are typically asked to leave first to help maintain an orderly flow of traffic.

A hurricane warning has been issued for parts of Mexico's Yucatan Peninsula, and a hurricane watch was in place in parts of Cuba.

In places in southwest Florida where many are still trying to recover from last year's Hurricane Charley, local officials were closely monitoring the forecasts.

"We haven't issued any evacuation orders yet," said Susan Bard, a spokeswoman for Charlotte County. "Right now it's just too soon to tell."

Indeed, forecasters said it was unclear where Wilma might turn. Feeding their uncertainty are the location and effect of a trough of low pressure over the United States.

If the hurricane comes under the trough's influence, it is likely to head north and northeast and hit Florida, said Eric Blake, a National Hurricane Center meteorologist. If not, it could move westward to the Yucatan Peninsula, or stay still.

"One of the most difficult forecasts in meteorology is whether a trough will pick up a hurricane or not -- that's where some of the largest errors are," Blake said. "Small changes initially can lead to big changes in the long range."

He said that one forecasting model had Wilma being near Maine five days from now. Then, six hours later, the model showed Wilma near Cuba in that time frame, a difference of about 1,700 miles, he said.

The maximum sustained winds as of 5 p.m. yesterday were about 160 mph, and Wilma was deemed a "potentially catastrophic" Category 5 hurricane by the National Hurricane Center. Hurricane-force winds extended up to 60 miles.

Forecasters said Wilma is likely to weaken, possibly to Category 3 status, particularly if it slows down and lingers where it is, as some models project.

"We've learned over time that a consensus approach is best -- unless there is a very compelling reason otherwise," Blake said. And as of yesterday evening, "A majority [of the models] have it headed over Florida."

Tourists leave through the Playa del Carmen port in Mexico as Hurricane Wilma approaches the area, threatening Florida and Cuba as well as Mexico's Yucatan Peninsula.