Tropical Storm Erin formed in the eastern Atlantic Ocean on Monday, forecasters said. The storm could strengthen to become the Atlantic's first hurricane of the season.

Erin’s sustained winds increased to 70 mph, just 4 mph shy of hurricane strength. The hurricane center said Erin should continue to strengthen through the weekend, when it should be moving near or north of the Leeward Islands, according to the official forecast path.

Hurricane Erin was downgraded to a Category 3 hurricane early Sunday as a tropical storm warning was issued for the Turks and Caicos Islands and winds and heavy rains whipped the Virgin Islands and Puerto Rico.