Forecasters said Erin should begin to slowly weaken as it increased wind shear. However, it's predicted to remain a major hurricane until late next week.

A stronger and bigger Hurricane Erin pelted parts of the Caribbean and is forecast to create dangerous surf along the U.S. East Coast this week.

While Erin is expected to take a northward turn in the Atlantic, a new system off the coast of Africa has the National Hurricane Center's attention.

Forecasters are watching a new tropical system that may form behind Hurricane Erin, which is intensifying again Monday as it tracks off the U.S. coast.

Offshore Hurricane Erin was downgraded to a Category 3 storm early Sunday, as rain lashed Caribbean islands and weather officials warned of possible flash floods and landslides.It also warned of "locally considerable flash and urban flooding,

Despite this, the US National Hurricane Center (NHC) says Erin is growing in size, with tropical-storm-strength winds extending 205 miles from its centre. Storm-related hazards, including flash flooding and landslides, are expected in the Virgin Islands and Puerto Rico.

The storm will remain a major hurricane through the middle of the week, according to the National Hurricane Center.

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 restrengthened into a Category 4 storm late Sunday, with forecasters warning it is expected to intensify and grow in size in the coming days as it lashes Caribbean islands with heavy rains that could cause flash floods and landslides.

Erin, the first hurricane of the season, is now forecast to become a Category 4 by Sunday. Here's where it could head in the week ahead.