Niwa Seasonal Forecaste - LA NINA

good name for it I think "anticyclonic gloom"

 

Background

Following the La Niña event over July 2010 to April 2011, the tropical Pacific returned to neutral conditions. However, over the past 4-6 weeks there is mounting evidence of a transition back to La Niña conditions. The Southern Oscillation Index has become more positive, sea surface temperature anomalies have become increasingly negative in the east-central equatorial Pacific, and the easterly trade winds have intensified near the Date Line. There has been a major shift in the consensus from global climate models which predict El Niño-Southern Oscillation conditions. The majority of these models are now forecasting further development of La Niña patterns over spring and a continuation through the summer of 2011/12. At this early stage, we cannot be confident about the intensity of the event.