El Niño/La Niña Update (December 2014)

Steady warming of the tropical Pacific Ocean over the past two months has resulted in ocean surface temperatures reaching weak El Niño levels. However, the overlying atmosphere is showing a mix of responses, with some indicators exceeding El Nino thresholds, while others remain neutral. Models and expert opinion suggest there is approximately a 70% chance that a weak El Niño event will become established before the end of February 2015. If an event does occur, it is most likely to be weak and persist for the first quarter of 2015. Some El Nino-like impacts have already been observed in several countries, and impacts in other areas may develop regardless of whether an El Nino becomes fully established. 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.