Tropical Storm Erin formed on Monday and is expected to become a hurricane, and possibly a major hurricane, later this week.

Tropical Storm Erin is expected to strengthen into a hurricane later this week in the Atlantic Ocean, according to the National Hurricane Center.

Erin’s long-range track was still the subject of much speculation, with it being too soon to rule out threats to the U.S. Many forecast models suggest the storm, which could become a Category 3 hurricane by late this week, will track westward but then turn to the north and then northeast, keeping it off the U.S. East Coast.