The system began in the third week of August as a persistent tropical disturbance south of the Hawaiian Islands. It was initially embedded in a trough, but gained convection and developed into a tropical depression about 775 miles south of Honolulu on August 19. It continued to strengthen, and the Central Pacific Hurricane Center designated the system with the name "Ioke" (IPA /iːˈəʊ.keɪ/), which is Hawaiian for the name Joyce, becoming the first tropical storm to form in the Central Pacific since 2002.