Hurricane Erin strengthened into a fearsome Category 5 hurricane with sustained winds of 160 mph for much of the day on Aug. 16 as it traveled west just north of the Virgin Islands, according to the National Hurricane Center.

Hurricane Erin has weakened slightly to a Category 4 storm while positioned northeast of Puerto Rico and is on course to brush along the U.S. East Coast.

Erin is the first hurricane to develop over the Atlantic this year, and meteorologists are closely tracking its path and forecast.