Hong Kong Observatory identified a tropical depression about 460 kilometres north of Yap on September 9, the same day the JMA recognised it. The JTWC declared the formation of Tropical Depression 14W the next day. On the afternoon of September 10, it entered the PAGASA AOR and was named Luis. Later at 12 p.m. UTC on the same day, the JMA upgraded the tropical depression to Tropical Storm Shanshan. The name Shanshan was contributed by Hong Kong and is a girls' name. Shanshan quickly strengthened and was upgraded into a severe tropical storm on September 11 and a typhoon later that day. Shanshan weakened slightly on September 14, but quickly restrengthened and reached Category 4 status on the JTWC's scale. Shanshan passed through the Yaeyama Islands in the early morning hours of September 16. The JTWC reported that Shanshan was becoming extratropical early on September 17, as the typhoon weakened to a tropical storm. The JTWC issued its final advisory on Shanshan later that day, and the JMA issued its last advisory on September 18, after Shanshan completed extratropical transition.