Hurricane Erin strengthened into a powerful Category 4 storm Saturday in the Caribbean, where it threatened to dump flooding

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

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.

Charley roared ashore near Cayo Costa, Florida, or west of Fort Myers, packing maximum sustained winds of 150 mph on the afternoon of Aug. 13, 2004. The intensification of Charley prior to landfall was a worst-case scenario since nearly eight hours earlier over the eastern Gulf, it was a Category 2 with 110 mph winds.