Hurricane Erin has been downgraded to a Category 3 hurricane but is gaining in size and raising the risk of life-threatening surf later this week along the U.S.

The peak intensity is now expected at a strong Cat 3 with winds of 125 mph. The storm will miss a direct hit to the Windward Islands, Puerto Rico, and Hispaniola. Once the system is north of Puerto Rico,

Hurricane Erin is churning slowly toward the eastern U.S. coast and stirring up waves that already have forced dozens of beach rescues

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.

NOAA's GOES-19 satellite captured images of Hurricane Erin as it developed in the Atlantic and then rapidly strengthened into a Category 5 storm.