MIAMI — Tropical Storm Erin has formed in the eastern Atlantic, southwest of the Cape Verde Islands.

The storm’s maximum sustained winds early Thursday are near 40 mph (65 kph) with additional strengthening forecast during the next few days.

A tropical storm warning is in effect for the southern Cape Verde Islands of Maio, Santiago, Fogo and Brava.

The storm is centered about 65 miles (100 kilometers) west-southwest of Brava and is moving west-northwest near 16 mph (26 kph).