Subsequent to the flight , satellite imagery indicated a low - level circulation was forming , and on June 25 ship .
Buoy data confirmed the system developed into Tropical Depression One while located about 235 miles ( 375 km ) west - southwest of Key West , Florida .
Subsequent to the flight , satellite imagery indicated a low - level circulation was forming , and on June 25 ship and buoy data confirmed the system developed into Tropical Depression One while located about 235 miles ( 375 km ) west - southwest of Key West , Florida .