The present El Nino event, on the cusp of attaining “strong” intensity, has a chance to become the most powerful on record. The event — defined by the expanding, deepening pool of warmer-than-normal ocean water in the tropical Pacific — has steadily grown stronger since the spring. The presence of a strong El Nino almost ensures that 2015 will become the warmest on record for Earth and will have ripple effects on weather patterns all over the world.

A strong El Nino event would likely lead to enhanced rainfall in California this fall and winter, a quieter than normal Atlantic hurricane season, a warmer than normal winter over large parts of the U.S., and a very active hurricane and typhoon season in the Pacific.Some of these El Nino-related effects have already manifested themselves and, over the U.S., will become particularly apparent by the fall and winter. MORE