Affiliate Specials Understanding the Phenomenon San Jose Mercury News (Calif.) Coming Soon, Effects Unknown San Jose Mercury News (Calif.) Tracking with better tools than ever San Jose Mercury News (Calif.) Coping with nature's wild card ocregister.com (Orange County, Calif.) Special Report: El Niño Los Angeles Times El Niño Grande The Gate (San Francisco) Government and Other Research Sites El Niño Loss Reduction Center Federal Emergency Management Agency NASA El Niño Site NASA/Goddard Space Flight Center The latest El Niño Data National Oceanic and Atmospheric Administration Weather World 2010 El Niño page University of Illinois Special Report: El Niño Los Angeles Times

For some reason that scientists cannot quite explain, tradewinds in the Pacific that normally blow west toward Indonesia and Australia, fade, stop or reverse themselves completely. This causes ocean currents of warm water to flow east toward South America. This is how El Niño begins. El Niño: A Primer ocregister.com (Orange County, Calif.) Graphic: An El Niño year vs. a normal year Access Atlanta The most destructive yet? washingontpost.com Clues in the clamshells SunOne (Gainsville, Fla.) Graphic: The making of El Niño washingtonpost.com Animation: 1997 compared to other El Niño years National Oceanic and Atmospheric Administration Animation: The latest surface sea temperature data National Oceanic and Atmospheric Administration More images of El Niño NASA/Goddard Space Flight Center