Puerto Rico Braces for Tropical Storm Ernesto

Puerto Rico has activated the National Guard and canceled the start of classes in public schools as forecasters warned that the U.S. territory would be hit by Tropical Storm Ernesto, which formed in the Atlantic Ocean on Monday.

Tropical storm warnings are in effect for Puerto Rico and a Hurricane watch is up for the Virgin Islands.

Ernesto's maximum sustained winds are 50 mph, according to the National Hurricane Center.

The storm is expected to spin out into the central Atlantic away from the US Mainland.