The World Meteorological Organization (WMO) issues regular El Nino / La Nina updates based on observational monitoring of the current situation, seasonal predictions through climate model simulations and input from top international experts. This publication, however, aims to explain the phenomenon in its typical manifestation from the physical mechanism to the global impacts including socioeconomic implications. Reliable forecast of El Nino / Southern Oscillation are a good example of a climate service that helps communities to reduce vulnerability and adapt... read the brochure