The trade winds bring in colder air to replace the air that has risen. They come out of the northeast in the Northern Hemisphere and out of the southeast in the Southern Hemisphere. See Trade wind on World Book Online . The prevailing westerlies in the Southern Hemisphere make up the strongest and steadiest wind belt because there is little continental interference to break up the wind system. Typhoons and hurricanes.
Tropical cyclones produce much of the rainfall in the Pacific area.
These great circular winds do not usually cause much damage, and they may bring needed rain to dry areas. But cyclones occasionally reach such high speeds that they become extremely violent. The most destructive of these storms howl down along the East China Sea and South China Sea between June and December and develop in the eastern North Pacific between May and November. Typhoon on World Book Online . Currents and tides.