Ike's center was located about 620 miles northwest of the Leeward Islands and was moving west-northwest at about 17 mph.
Forecasters at the National Hurricane Center in Miami say the storm is expected to continue on its current track Thursday before turning more to the west. It's too soon to tell which land areas could be threatened.
The storm is following behind Tropical Storm Hanna, which could threaten the southeastern coast of the U.S. by the weekend. Tropical Storm Josephine is following behind Ike.