The 2010-2011 La Niña was one of the strongest in recorded history. Though the La Niña was officially pronounced dead in April this year, this blog however had been predicting a multi-year La Niña with a short intervening period of ENSO neutral conditions during the boreal (northern hemisphere) summer. This was the basis of a pattern thrown up by the analysis of historical data.
There are preliminary indications that the 2010-2011 La Niña will be no different and most likely will taken on a multi-year character. The recent ENSO wrap up data of Bureau of Meteorology (BoM), Australia for instance shows the Southern Oscillation Index (SoI) in clear La Niña territory at +9.9 after a very brief period in neutral territory. (Note: Sustained positive values of the SOI above +8 may indicate a La Niña event). Similarly, the Niño 3.4 value have turned negative at - 0.2 C, seem inching back to La Niña territory/ (Note: Sustained value above - 0.5 C may indicate a La Niña event).