A tropical disturbance developed on September 10, in the western Philippine Sea but initially failed to develop as it interacted with Luzon. The disturbance passed over Luzon and entered the South China Sea, where it became more organized and developed into Tropical Depression 21W late on September 11. The system gradually strengthened as it moved northwest towards the Chinese coastline, reaching its peak as a 130 km/h (80 mph) typhoon as it turned towards Hong Kong on September 16. York made landfall to the west of Hong Kong soon after and dissipated into a low pressure area over China the next day. Both the JMA and PAGASA monitored York as a tropical storm, with PAGASA naming the system "Neneng".