The National Hurricane Center said in its 11 p.m. AST advisory Michael was pumping out winds near 75 mph on a sustained basis as it moved northeast at 7 mph. Tropical storm-force winds extended as much as 70 miles from its center.
The storm, located about 1,060 miles west-southwest of the Azores, was forecast to turn to the north-northwest Friday.
The hurricane center said the storm was no danger to land.
Leslie was upgraded from tropical storm status about 460 miles south-southeast of Bermuda Wednesday afternoon, becoming the sixth hurricane of the Atlantic hurricane season.