La Niña describes an extensive cooling of the waters in the tropical eastern Pacific Ocean. In that region of the Eastern Pacific, the prevailing trade winds are easterly. The lower-level winds drag or push the warm surface water westwards towards Indonesia, the Philippines and Australia. The ocean stirring upwells deep cooler waters to the surface along the South American coast. North America typically feels the effects of La Niña during the winter and early spring. Wetter-than-normal conditions occur across the Pacific Northwest, British Columbia and Alaska.