El Niño-Southern Oscillation (ENSO) The El Niño-Southern Oscillation (ENSO) is a recurring climate pattern involving changes in the temperature of waters in the central and eastern tropical Pacific Ocean. On periods ranging from about three to seven years, the surface waters across a large swath of the tropical Pacific Ocean warm or cool by anywhere from 1°C to 3°C, compared to normal. Ski resorts throughout the western United States have been doing the best they… Where’s the Snow? Blame it on ENSO!Read More Where’s the Snow? Blame it on ENSO!