 Typhoon Durian formed as a tropical depression on November 24, 2006 near Chuuk State.Situated south of a ridge, the system tracked west-northwest through a region of low wind shear and good upper-level divergence.Late on November 26, the depression intensified into a tropical storm and was named "Durian" by the Japan Meteorological Agency (JMA) Steady strengthening took place over the following two days as the system approached the Philippines.