Powerful Hurricane Erin has undergone a period of astonishingly rapid intensification — a phenomenon that has become far more common in recent years as the planet warms. It was a rare Category 5 for a time Saturday before becoming a Category 4,

Erin, which quickly strengthened into a Category 5 storm on Saturday, is not expected to make landfall in the U.S., but experts remain on alert.

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

Erin, the first hurricane of the season, is now a powerful Category 5 hurricane. Here's where it could head in the week ahead.

Erin has intensified to a Category Five Hurricane as it makes its way toward the East Coast of the United States.