U.S. shores are unlikely to see a direct hit, but a strong offshore hurricane can produce massive and dangerous waves well away from its center.

Hurricane Erin strengthened into a Category 4 storm as U.S. officials warned of dangerous rip currents expected this week.

Hurricane Erin has reintensified into a Category 4 storm on Aug. 18, according to the National Hurricane Center. See where Erin is headed.