Wilma, the record-tying 12th hurricane of the Atlantic season, strengthened to become a major Category 4 storm early Wednesday, setting a course to sideswipe Central America or 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 ( 241 kph). It was only Tuesday morning that Wilma grew from a tropical storm into a weak hurricane, with 80 mph (130 kph) winds. The storm could become a Category 5 sometime Wednesday, 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 of Mexico.