Erin is the fifth named storm to develop during the Atlantic hurricane season, which started just over two months ago. Last week, Tropical Storm Dexter formed in the western Atlantic but didn't pose a threat to land. In early July, Tropical Storm Chantal made landfall on the Carolina coast, bringing deadly flooding to the region.

Tropical Storm Erin continues to move quickly west, and is expected to become the first hurricane of the Atlantic season.

Tropical Storm Erin is expected to strengthen into a hurricane later this week in the Atlantic Ocean, according to the National Hurricane Center.