Forecasters said a tropical depression is speeding toward a chain of small, popular vacation islands in the Caribbean Sea. The National Hurricane Center in Miami said Thursday afternoon that the system formed in the Atlantic Ocean and is headed west toward the Caribbean. Tropical storm watches are in effect for the islands of Barbados, Dominica and St. Lucia. The depression's maximum sustained winds are at 35 mph (55 kph) and the storm is moving to the west at 20 mph (32 kph), AP reported. Forecasters said the storm is expected to strengthen. Its general track takes it toward Jamaica, though forecasters warn that the path of a tropical system can be unpredictable.