A group of scattered tropical thunderstorms 200 km south of Bermuda, strengthened into the fifth tropical depression of the 1983 season. An Air Force Reconnaissance aircraft found winds of 35 kt (40 mph, 65 km/h) and was named Tropical Storm Chantal. Chantal continued to strengthen and developed into a minimal hurricane with 75 mph (120 km/h) winds on September 11 and maintained that strength until September 13, when it weakened back into a tropical storm.