The chances that rain and wind from Tropical Storm Erin will hit the East Coast have risen slightly this week.

Tropical Storm Erin is slightly intensifying and forecast to become a hurricane Friday with a chance of ultimately affecting the U.S. East Coast next week.

Tropical Storm Erin is forecast to become the season’s first hurricane by Thursday. The storm, which earned a name early Monday and is churning in the open Atlantic, could strengthen into a major hurricane of at least Category 3 strength by this weekend.