Hurricane Erin has restrengthened to a Category 4 storm as it turns northwest and is expected to remain east of the U.S., according to the National Hurricane Center.

Hurricane Erin exploded in strength and became a major storm in Atlantic waters just north of the Caribbean on Saturday, rapidly powering up from a tropical storm in a single day.

Even more hurricanes are rapidly intensifying in the Atlantic as the oceans and atmosphere warm in response to fossil fuel pollution and the global warming it causes.