Sonca was a TS tropical cyclone that formed in the South China Sea in 2017. The storm reached maximum sustained winds of 65 km/h (35 kt) with a minimum central pressure of 994 hPa. Tracking across the South China Seain the Western Pacific basin (, it potentially affected Vietnam, the Philippines, China and Taiwan. The storm traveled from approximately 16.1°103.9° to 17.8°116.0°, crossing a range of 2 latitude and 12 longitude.