Where Is Wilma Headed?

Powerful Hurricane Pounds Caribbean But Future Path Remains Unknown

(CBS/AP)  The fringes of Hurricane Wilma lashed Caribbean nations on Wednesday, forcing schools to close and thousands to evacuate as it churned toward Mexico's Cancun resort and Florida after killing at least 12 people and becoming the most intense storm ever to form in the Atlantic.

The National Hurricane Center says Wilma weakened to a Category 4 hurricane with maximum winds near 155 mph.

Still, the center in Miami warned that Wilma would be a "significant threat" to Florida by the weekend in a season that has already seen devastation from Hurricanes Katrina and Rita. Officials ordered tourists out of the Florida Keys.

But CBS News hurricane expert Bryan Norcross said that Wilma is throwing forecasters for a loop (video), as new computer models are giving diverging scenarios, including the possibility that the hurricane will miss Florida altogether.

"Confidence in the forecast has gone down significantly," Norcross said.

CBS News correspondent Jim Acosta reports that a usually mild-mannered Max Mayfield, the director of the National Hurricane Center, ramped up the tension.

"We had well over 1,000 lives lost in Katrina. If Wilma, you know, comes into the U.S., to the Florida coast as a Category 3 or 4 hurricane, that potential for large loss of life is with us," he said.

The White House, stung by criticism that it had not responded quickly enough to Katrina, promised to stay on top of the situation. "We are closely monitoring what is an extremely dangerous storm," said White House spokesman Scott McClellan. "People should take this hurricane very seriously."

Tourists packed Cancun's airport in hopes of catching flights out and MTV postponed its Video Music Awards Latin America ceremony, originally scheduled for Thursday at a seaside park south of the resort town.

Floridians braced for the storm by boarding up windows and stocking up on supplies, although forecasters at the hurricane center said the forward motion of the storm appeared to be slowing, which could cause it to eventually weaken.

Mayfield said Wilma may not reach the Florida Keys until Saturday, possibly toward the evening. It had earlier been expected to reach the Florida mainland Saturday.

"We're gonna batten down the hatches, take our boat, and run to Northern Florida," Wally Graskoski, a resident of Punta Gorda, Fla., told Acosta.

Heavy rain from Wilma's outer bands also forced evacuations in Honduras, Cuba, Jamaica and Haiti — even as much of Central America and southern Mexico was still recovering from Hurricane Stan, which left more than 1,500 people dead or missing.

Wilma was on a curving course that would carry it through the narrow channel between Cuba and Mexico on Friday, possibly within a few miles of Cancun and Cozumel.

At 11 p.m. EDT, the massive storm was centered 235 miles southeast of Mexico's Cozumel Island, and was moving west-northwest at 8 mph.

Wilma's confirmed pressure readings early Wednesday dropped to 882 millibars, the lowest minimum pressure ever measured in a hurricane in the Americas, but it later lost power and rose to 900 millibars, according to the hurricane center. Lower pressure translates into higher wind speed.

The strongest Atlantic storm on record, based on pressure readings, had been Hurricane Gilbert in 1988, which registered 888 millibars.