Tropical Storm Erin was expected to strengthen into a hurricane on Friday as it approached the northeast Caribbean, prompting forecasters to warn of possible flooding and landslides. The storm is expected to remain over open waters,

Heavy rains are forecast to start with the storm expected to become a major Category 3 storm over the weekend.

Erin, the first hurricane of the season, is now forecast to become a Category 4 by Sunday. Here's where it could head in the week ahead.