It quickly powered up from a tropical storm to a Category 5 in a single day, the National Hurricane Center said.

Over the weekend, Erin is expected to rapidly intensify all the way to a Category 3 hurricane. By Monday, as the storm steers away from the Caribbean and toward Bermuda, it's now forecast to hit Category 4 with 130 mph sustained winds. Some long-term computer models suggest it could get even stronger and hit Category 5 in the open ocean.