Tropical Pacific has switched from warm to cold

La Niña has recently taken hold over El Niño. During a La Niña, trade winds in the western equatorial Pacific are stronger than normal, and cold water that normally exists along the coast of South America extends to the central equatorial Pacific. La Niñas change global weather patterns and are associated with less moisture in the air, resulting in less rain along the coasts of North and South America. They also tend to increase the formation of tropical storms in the Atlantic. See Adios El Niño, Hello La Niña?