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.

Erin, the first hurricane of the season, is now a powerful Category 5 hurricane. Here's where it could head in the week ahead.

The storm is not currently forecast to hit land, but its strong winds are impacting nearby islands, prompting warnings of possible flooding and landslides.

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.

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

Implications for the Leeward Islands: Residents and visitors in St. Thomas, St. John, St. Croix, Puerto Rico and the northern Leeward Islands should monitor this system throughout the week. Even if the wave remains weak, increased moisture could bring showers, gusty winds and higher seas toward the end of the week.