First Look At ENSO- Where are we Going?

Towards the middle of the summer, I always like to get a general idea of where ENSO is heading from here. Last summer, we were just recovering from a strong El Nino, heading into a La Nina stage which eventually peaked at a moderate level. Currently, we are in ENSO neutral conditions, with neither positive or negative SST anomalies in the Pacific.

This asks the question: Where are we headed now?

Although some may disagree, I'm confident we head back into La Nina territory, but just barely reaching the official recognition (5 consecutive tri-monthly readings below -.5). After two extreme ENSO events, there isn't much "energy" left to work with, and I think that SSTs will slowly drop this summer and into the winter. 

A current look at ENSO conditions shows that we had a rapid rise in SSTs earlier this month, and it is well coupled with other global dynamics such as the SOI, MJO, GWO and GLAAM. 

As you can see from the graph, this past spring we saw a rapid drop in the SOI, going from positive values to near zero. Typically a +SOI coincides with a La Nina, and vice-versa. Since then the SOI has slowly risen back to positive values, which indicates that ENSO will stop warming. 

The GLAAM rose quickly during the brief period of ENSO warming, with the highest positive anomalies along the equator. After early June, however, the GLAAM has fallen back into negative territory, and looks to remain there for quite some time. 

The PDO has also taken on textbook characteristics of a -PDO. A warm pool south of the Aleutian Islands, with a cold pool off the Pacific Northwest Coast and towards the Alaskan Coast. We have just recently seen a switch in the PDO, which reverses approximately every 30 years. the PDO has been negative almost every month in the last 3 years, starting with the last El Nino of 2007-2008. 

With all these factors pointing towards a La Nina, it's not that hard to predict we will head back into Negative ENSO territory. However, how far negative we get remains to be seen. The CFS (shown below) continues to be the most aggressive, with other foreign models such as the ECMWF (not shown) are much less aggressive.  

A global model average stands at approximately -.2*C anomalies, which seems slightly too conservative to me. However, the fact that almost no models are predicting an El Nino does give some extra confidence to my forecast of a weak (very weak) La Nina. 

Comments/Questions are appreciated as always!