Hurricane Erin weakened slightly to a Category 3 storm Sunday and, although it is slightly more south than originally forecast, is still expected to be east of the U.S. coast. Meanwhile, a new

Hurricane Erin is likely to restrengthen again as it passes east of the Turks and Caicos Islands and the southeast Bahamas on Monday after lashing the Caribbean with damaging winds and flooding rain.

Storms that ramp up so quickly complicate forecasting and make it harder for government agencies to plan for emergencies. Hurricane Erick, a Pacific storm that made landfall June 19 in Oaxaca, Mexico, also strengthened rapidly, doubling in intensity in less than a day.