Erin is expected to develop into a hurricane later this week and could affect Puerto Rico, the Virgin Islands and the northern Leeward Islands.

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.