Tropical Storm Erin is tracking west over the open Atlantic Ocean on Tuesday and forecasters expect it to become the first hurricane of the Atlantic season this week.

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

Tropical Storm Erin has formed on a path toward the Caribbean and is expected to strengthen to a hurricane later in the week as it passes by Puerto Rico. Most models forecast the storm turning upward into the Atlantic Ocean, but a few see the storm continuing onward to the U.S. mainland.