Tropical Storm Erin is nearly at hurricane strength Thursday night, its western path putting islands in the far eastern Caribbean under tropical storm watches, according to the National Hurricane

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.

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.