AU-PRINCE, Haiti, August 17, SPA -- Tropical Storm Fay roared toward Cuba on Sunday after lashing Haiti and the Dominican Republic with torrential rains and floods that killed at least four people, the Associated Press reported. Forecasters said Fay was expected to strengthen on Sunday and could be hurricane strength when it passes over Cuba and zeros in on Florida, where officials declared a state of emergency. A hurricane watch was issued for the Florida Keys and parts of south Florida on Sunday. The U.S. National Hurricane Center in Miami said that at 0900 GMT Sunday the center of the storm was about 445 miles (715 kilometers) southeast of Key West, Florida. It was moving toward the west-northwest at 13 mph (21 kph), with maximum sustained winds at 50 mph (80 kph). Cuba's government said a hurricane watch was in effect for the island from the province of Matanzas east to Sancti Spiritus, and a tropical storm warning was in effect for Guantanamo Bay. Fay's path was expected to take it near the southern coast of the island on Sunday and over western Cuba on Sunday night or Monday.