Hurricane Erin strengthened into a Category 2 storm on Friday as it approached the northeast Caribbean, prompting forecasters to warn of possible flooding and landslides.

Hurricane Erin is rapidly intensifying as it tracks above the northeastern Caribbean Saturday, churning up rough surf and sending rain and gusty winds to islands south of its path.

The threat of direct impacts in the Bahamas and along the east coast of the United States appears to be gradually decreasing, although there will be a significant risk of dangerous surf and rip curre...