Tropical Storm Oscar formed in the eastern tropical Atlantic Wednesday, becoming the 15th named storm of the 2012 hurricane season, the National Hurricane Center in Miami said.
As of 11 p.m., Oscar was moving north-northwest at 12 mph about 1,220 miles west-northwest of the Cape Verde Islands. It had maximum sustained winds of 40 miles per hour.
The storm became Tropical Depression 15 earlier Wednesday.
A turn toward the north with a decrease in forward speed was expected by Thursday.