Yanyan was a TS tropical cyclone that formed in the Philippine Sea in 2003. The storm reached maximum sustained winds of 65 km/h (35 kt) with a minimum central pressure of 1000 hPa. Tracking across the Philippine Seain the Western Pacific basin (, it potentially affected the Philippines, Taiwan and Japan. The storm traveled from approximately 1.3°146.6° to 18.6°180.2°, crossing a range of 17 latitude and 34 longitude.