The system drifted slowly in a westward direction until it started deteriorating, and the JMA downgraded the depression to a low-pressure area late on October 7. Its remnants continued moving westward which became Tropical Storm Koppu. During October 19, the JMA started to monitor a tropical depression that had developed, about to the south-west of Wake Island. The system was located within a marginal environment for further development, with moderate vertical wind shear and weak convergence preventing atmospheric convection from developing over the depression. Over the next couple of days the system moved and near the subsidence side of Typhoon Champi, before it was last noted by the JMA on October 22. The final tropical depression of the system developed on December 20 north of Malaysia. The system moved in a slow westward direction for a few days until it was last monitored on December 23, ending the season. Within the Northwest Pacific Ocean, both the Japan Meteorological Agency (JMA) and the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) assign names to tropical cyclones that develop in the Western Pacific, which can result in a tropical cyclone having two names. The Japan Meteorological Agency's RSMC Tokyo — Typhoon Center assigns international names to tropical cyclones on behalf of the World Meteorological Organization's Typhoon Committee, should they be judged to have 10-minute sustained windspeeds of . PAGASA names to tropical cyclones which move into or form as a tropical depression in their area of responsibility located between 135°E and 115°E and between 5°N and 25°N even if the cyclone has had an international name assigned to it. The names of significant tropical cyclones are retired, by both PAGASA and the Typhoon Committee. Should the list of names for the Philippine region be exhausted then names will be taken from an auxiliary list of which the first ten are published each season. Unused names are marked in . During the season 25 tropical storms developed in the Western Pacific and each one was named by the JMA, when the system was judged to have 10-minute sustained windspeeds of . The JMA selected the names from a list of 140 names, that had been developed by the 14 members nations and territories of the ESCAP/WMO Typhoon Committee. During the season the names Atsani, Champi and In-fa were used for the first time, after they had replaced the names Morakot, Ketsana and Parma, which were retired after the 2009 season.