KINGSTON, Jamaica (AP) -- Jamaicans are bracing for sheets of rain, violent winds and a powerful storm surge as a strengthening Tropical Storm Sandy closes in.

Sandy is expected to dump at least 10 inches of rain in parts of Jamaica. The storm's outer bands have already brought intermittent showers to the Caribbean island.

The National Hurricane Center in Miami says Sandy is expected to become a hurricane as it nears Jamaica tomorrow, then travel over the island from south to north.

Jamaica's government has issued a hurricane warning and is warning people in flood-prone areas to be on alert.

Cuba has issued a hurricane watch for several provinces, including Guantanamo. Because of the storm, authorities at the U.S. base there are trying to condense the agenda for the military commission hearings that are going on.

Forecasters say hurricane conditions are possible in eastern Cuba by tomorrow night.

Late this morning, Sandy was centered about 300 miles south-southwest of Jamaica, moving north at about 5 mph. Its maximum sustained winds were near 50 mph.

Meanwhile, a tropical depression far out in the Atlantic is expected to become a tropical storm today. But it doesn't pose any threat to land.