Friday, May 20, 2011

El Nino/La Nina Projections (May 20)

The IRI has updated their ensembles containing what climate models believe will happen in regards to El Nino or La Nina.
Below is the Ensemble.
The average of all models actually went down by .1 degree Celsius from the April forecast to the May forecast.
As we can see, there are outliers, but the general consensus is for a neutral winter, as the average is at or below .5 degrees Celsius.
The CPC also makes an ENSO (name for El nino/La Nina) projection.
Below are the ensembles from the latest 10 days.
This ensemble also has a neutral winter in mind for the United States. However, the latest 10 forecast members to get in on this ensemble would have the most accurate information. That said, it appears the outliers on the ensemble are actually more into a La Nina/neutral winter phase instead of an El Nino/neutral winter phase.
Is this a sign of things to come?
I do have more images from the IRI to answer this question.
I took a look at the individual models that make up the ensembles and found 3 that compared good in past forecasts to what played out.
Those 3 models are the
ECMWF model
JMA Model
ESSIC Model
The ECMWF model above didn't have a clear bias, which was good. Even better, the forecasts had been nearly always on track with what happened, especially during the last several months.
The ESSIC model above does seem to have somewhat of a La Nina bias. While it's been right for some time, the El Nino wasn't handled correctly during 2009. But, since it does get it's forecasts right at some points, I had to include it.
Finally, the JMA model does seem to have a slight El Nino bias, but it shows only to some extent. The forecasts were nearly right on track with what happened, just a little warmer during the El Nino.

In conclusion, I am going towards a neutral 2011 as we move into the rest of the year.
Another projection will be made next month.

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