Weather experts on the Leeward Islands, including Puerto Rico, are keeping close watch as Erin lurches toward the Caribbean and is on track to become a major hurricane.

Hurricane Erin has been downgraded to a Category 3 hurricane. Hurricane Erin was downgraded to a Category 3 hurricane early Sunday as a tropical storm warning was issued for the Turks and Caicos Islands and winds and heavy rains whipped the Virgin Islands and Puerto Rico.

The outer bands of powerful Hurricane Erin lashed Puerto Rico, and the storm is approaching the Bahamas next. What can the mainland U.S. expect?