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.

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

The National Hurricane Center's prediction cone shows a westward trajectory, but doesn't paint a clear picture whether or not it's likely to impact the east coast of the United States. Spaghetti models, which represent a collection of predicted paths generated by multiple computer models, paint a more definitive picture as of Wednesday morning.