Monday, May 9, 2011

La Nina conditions ending

The latest pictures show that the cold, blue strip along the equatorial Pacific Ocean - which is associated with La Nina - has largely disappeared:



On the contrary, a warm, orange cloud is spreading from the South American Western beaches towards the West. The latest weekly summary of the ENSO dynamics shows that the Nino 3.4 anomaly has converged closer to zero - now it is at -0.5 °C which is just the boundary that defines the La Nina conditions. Chances are that by the next week, the reading will be between -0.5 and +0.5 which will indicate ENSO-neutral conditions.




The La Nina episode is delineated by the 3-month averages - and the averages up to March-April-May and maybe even April-May-June 2011 will remain in the La Nina territory. I find it slightly more likely than not that we will enter another El Nino episode after the ENSO-neutral conditions in the Summer.

Because the transition to ENSO-neutral conditions or El Nino will occur approximately in June and because the global mean temperature approximately responds with a 6-month delay, it's likely that the year 2011 will remain cooler than the average year of the recent era.

RSS AMSU satellite methodology has determined that the global temperature anomaly in April 2011 was just +0.11 °C which is 0.14 °C warmer than March 2011 but it is still the second coolest April since 1998 (included), after April 2008 which was even cooler.