Published: Sep 08, 2010 4:43 PM EDT
Updated: Sep 08, 2010 1:44 PM EDT

MIAMI (AP) - Tropical Storm Igor has formed in the Atlantic Ocean off the coast of Africa near the Cape Verde Islands and has top sustained winds of near 40 mph (65 kph).

Forecasters at the U.S. National Hurricane Center in Miami said Wednesday that Igor was moving toward the west near 8 mph (13 kph). The center of the storm is expected to pass south of the Cape Verde Islands by Thursday.

A tropical storm watch has been issued for the southern Cape Verde Islands.

Some slow strengthening is expected over the next two days.