TYPOON A typhoon is a mature tropical cyclone that develops between 180° and 100°E in the Northern Hemisphere . This region is referred to as the Northwestern Pacific Basin ,and is the most active tropical cyclone basin on Earth , accounting for almost one-third of the world's annual tropical cyclones. A typhoon differs from a cyclone or hurricane only on the basis of location.A hurricane is a storm that occurs in the Atlantic Ocean or northeastern Pacific Ocean , a typhoon occurs in the northwestern Pacific Ocean, and a tropical cyclone occurs in the south Pacific or Indian Ocean . Within the northwestern Pacific, there are no official typhoon seasons as tropical cyclones form throughout the year. Like any tropical cyclone, there are a few main...