Tropical Storm Erin is continuing to move west and is forecast to become a hurricane later this week, according to the National Hurricane Center.

Tropical Storm Erin may near Puerto Rico and the Dominican Republic before likely turning north as a hurricane, sparing the U.S.

Swells generated by Erin will begin affecting portions of the northern Leeward Islands, the Virgin Islands and Puerto Rico by this weekend, according to the National Hurricane Center. "These swells are likely to cause life-threatening surf and rip current conditions."