Storms that ramp up so quickly complicate forecasting and make it harder for government agencies to plan for emergencies.

Erin reached Category 5 status before weakening but has brought significant rain to the Virgin Islands and Puerto Rico.

Hurricane Erin has strengthened into a Category 2 storm as it approaches Puerto Rico and the Virgin Islands, bringing heavy ...

Erin is forecast to become a Category 4 hurricane, threatening Puerto Rico, Bermuda, and U.S. coasts with flooding and surf.

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