Fujiwhara effect
A tropical wave formed on October 26 near Ulithi and Woleai Atoll. The wave moved to the northwest and strengthened from a wave into a Category 3 typhoon with winds of . Interaction from the active Typhoon Gilda caused a Fujiwhara effect between the two and caused Ivy to weaken at a rapid pace from a Category 3 typhoon to a minimal tropical storm in 48 hours. The stronger Typhoon Gilda absorbed the weak Ivy on October 29 south of Iwo Jima.