El Niño/La Niña Update (March 2006)

Since around the turn of the year, sea-surface temperatures (SSTs) in the central and eastern equatorial Pacific have ranged between half and one degree Celsius below normal. Combined with broader tropical Pacific ocean and atmosphere conditions, this is consistent with the early stages of a basin-wide La Niña event. However, the development of basin-wide La Niña conditions at this time of the year is highly unusual, hence there is some additional uncertainty over the extent to which typical La Niña rainfall and temperature patterns will occur for this event. Furthermore, the La Niña conditions are expected to be relatively short-lived, with a return to neutral conditions across the equatorial Pacific likely by mid-year or shortly thereafter.