A strengthening Hurricane Dean headed toward Jamaica after barreling across the eastern Caribbean - leaving behind floods, debris and at least three deaths. The powerful Category 4 hurricane, the first of the Atlantic season, was expected to move Saturday across the warm waters of the Caribbean. Forecasters said it could turn into a monster storm with 150 mph (240 kph) winds bound for the Yucatan Peninsula and the Gulf of Mexico. By Wednesday, it could be threatening the United States. The immediate threat, however, comes Saturday as the storm passes south of Hispaniola, the island shared by the Dominican Republic and Haiti _ both particularly prone to devastating floods.