National Weather Service Weather Forecast Office

From the Climate Prediction Center (CPC)

Conditions are favorable for a transition from ENSO-neutral to El Niño conditions during June - August 2009.

SSTs have warmed continuously since the beginning of the year across the equatorial Pacific Ocean, with positive SST anomalies recorded during May across much of the central and eastern equatorial Pacific. At the same time, atmospheric conditions continue to reflect ENSO-neutral conditions, with near average upper- and lower-level winds observed across the central equatorial Pacific Ocean.  There continues to be considerable spread in the model SST forecasts for the central tropical Pacific. The statistical models predict ENSO-neutral conditions to continue through the remainder of 2009.  However, nearly all of the dynamical models, including the NCEP Climate Forecast System, predict the development of El Niño during June − August 2009.  Based on current observations, recent trends, and the dynamical model forecasts, a transition from ENSO-neutral to El Niño conditions is possible during June − August 2009.

For more information go to the CPC ENSO Diagnostic Dicussion