Lan was a C2 tropical cyclone that formed in the East China Sea in 2017. The storm reached maximum sustained winds of 185 km/h (100 kt) with a minimum central pressure of 915 hPa. Tracking across the East China Seain the Western Pacific basin (, it potentially affected Japan, Korea, Taiwan and eastern China. The storm traveled from approximately 8.7°129.9° to 39.1°143.6°, crossing a range of 30 latitude and 14 longitude.