[el ˈniɲo]) is the warm phase of the El Nino Niño Southern (oscillation commonly CALLED) enso and is associated with a band of warm ocean water that develops in the central and-east central Equatorial (pacific between approximately The International Date line and°120), w including off The pacific coast Of South. americainters, during the El Nino niño, effect are warmer and drier than average in The, northwest Northern, midwest and Upper Northeast United, states so those regions experience reduced. snowfalls