SEA SURFACE TEMPERATURE (SST)

The patterns of anomalous ocean temperatures, atmospheric circulation and precipitation are consistent in indicating weakening La Niña conditions in the tropical Pacific. During March negative equatorial SST anomalies less than –0.5ºC were observed at most locations between 180ºW and 90ºW, and SST departures were near zero in all of the Niño regions, except for Niño 1+2 (along the equatorial Pacific coast of South America). During March and April, positive SST departures decreased in the extreme eastern equatorial Pacific, and appear to be returning to near average in that region. The equatorial subsurface temperature anomaly pattern (negative anomalies in the central and eastern Pacific and positive anomalies in the western Pacific) which persisted during February-March 2006 is diminishing. The latest SST show equatorial SST near average except the negative anomalies near the far eastern Pacific. These oceanic features are consistent with weakening La Niña conditions and a return to ENSO Neutral conditions.