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,

Forecasters say Hurricane Erin has exploded into a Category 5 storm in the Atlantic Ocean just north of the Caribbean. The National Hurricane Center says the storm is north of the island of Anguilla with winds of 160 mph.