Wind shear
In addition to the 11 named storms, one of which failed to attain tropical storm status, there were several additional systems. The first was Tropical Depression C1, that originated from the ITCZ in the northeastern portion of the basin from a small area of convection on November 24. It moved westward with pulsating convection around the center, failing to organize due to the presence of wind shear. On December 4, the system organized into a tropical disturbance, and three days later it passed about north of the northern tip of Madagascar. That day, it intensified to tropical depression status, reaching peak winds of . Increased wind shear weakened the convection, and the circulation dissipated on December 10. On December 18, a tropical low developed in the Australian basin northeast of the Cocos Islands. It moved southwestward, intensifying into a tropical storm and being named Ken by the BoM. Wind shear in the region prevented much development, and the storm crossed into the south-west Indian Ocean on December 21. At that time, the MFR classified the system as Tropical Depression C2, but the agency only issued two warnings. The JTWC tracked the system until December 23 when the system dissipated well to the southwest of Indonesia.