El Niño/La Niña Update (March 2015)

Since late October 2014, sea surface temperatures in the tropical Pacific Ocean have remained at near-borderline to weak El Niño levels. However, many atmospheric features of El Niño have displayed only weak or short-lived responses to the warming. For example, the pattern of cloudiness and rainfall anomalies has not been well defined. Models and expert opinion suggest a continuation of warm-neutral to weak El Niño conditions through April and May of 2015. Most models suggest tropical Pacific temperatures will exceed El Niño thresholds toward the middle of the year. However, many models currently show a substantial spread in their outlooks for tropical Pacific Ocean temperatures, consistent with the known period of lower skill in longer lead predictions made at this time of year. This spread indicates that a range of outcomes remain possible, from neutral to a substantial El Niño event. This spread will narrow in the coming months as skill levels increase. National Meteorological and Hydrological Services and other agencies will continue to monitor Pacific Ocean conditions for further El Niño developments, and will assess the most likely local impacts.