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.

The chances that the storm will make landfall in the U.S. have increased slightly after the path shifted south.

Erin is expected to gradually strengthen over the coming days, with forecasters predicting it could reach hurricane status by late in the week.

Tropical Storm Erin is forecast to track in the direction of the U.S. coast and reach major hurricane strength by this weekend. Here’s the last forecast path.

Tropical Storm Erin is expected to become a hurricane, according to the NHC's advisory. What's the impact to Palm Beach County and Florida?

Erin will soon strengthen into the Atlantic season’s first hurricane. Find out where it’s headed and how strong it may get.

Forecasters say Tropical Storm Erin has formed in the eastern tropical Atlantic and could reach hurricane strength later in the week

Tropical Storm Erin formed in the eastern Atlantic Ocean on Monday, becoming the fifth named storm of the Atlantic hurricane season. Newsweek's live blog is closed.

Tropical Storm Erin continues to move quickly west, and is expected to become the first hurricane of the Atlantic season.