ORLANDO, Fla. — Tropical Storm Fiona, the hurricane season’s sixth named storm, formed Wednesday night east of the Leeward Islands, the National Hurricane Center said. In a special advisory issued shortly before 10 p.m. EDT, the NHC said that satellite data showed Tropical Depression 7 had strengthen to the point it was upgraded to Tropical Storm Fiona. It is not yet known if the tropical storm would have any impact to Florida or the mainland United States. The storm was located about 645 miles east of the Leeward Island and moving west at 14 mph. Earlier in the day Wednesday, when Fiona was s…