Leftover warm water in Pacific Ocean fueled massive El Nino

A new study provides insight into how the current El Niño, one of the strongest on record, formed in the Pacific Ocean. The new research finds easterly winds in the tropical Pacific Ocean stalled a potential El Niño in 2014 and left a swath of warm water in the central Pacific. The presence of that warm water stacked the deck for a monster El Niño to occur in 2015, according to the study's authors.