Research For The Winter 2011-2012 Winter Forecast!

The purpose of this post is to show people exactly what La Nina Winters looked like and then to come to a reasonable conclusion from there. It is important to remember that just because the ENSO is LA NINA does NOT mean that is the only thing that counts. If you think that..then you know NADA about the weather. We are going to look at the warm years first..

Those are the warm years. In general there were 11 La Nina winters that ended up above normal across a good portion of the US or the NE in general which is what we are looking at..

Now lets look at the colder years ..

Now as you can see by the images above we have ten years that were considered colder then normal or at the very least average temperatures. NOW if winter depended on ENSO alone ..one could make an argument that because this winter of 2012 is going to be La Nina…odds slightly favor a warmer winter..However…that is not the way it works!

As we have discussed in our winter outlook there are other teleconnections that need to be looked at.

One of those is the Pacific Decadal Oscillation. We are currently in a negative PDO (click here)

So out of the years above lets look and see what were negative PDO years..

1950,1954,1973,1974,1975,1976,1989,1999,2000,2008, (those are the warm years that were –PDO)

1955,1956, 1962,1964,1967, 1971,2011 (these were the colder la Ninas with a negative PDO…

So with looking at LA Nina years that were negative PDO we are now down to 17 years out of 21 years. Now lets look at the Quasi Biennial Oscillation or QBO ..We are presently negative (-0.49 click here)

1950,1954, 1974,1975.1989, 2008 (those are the warm years)

1955,1956,1970,1971,1984,2001 (these are the cold la nina winters with a –QBO..

As you can see we have now covered the –QBO years and the – PDO years when the Enso was La Nina..

Now another oscillation to look at is the AMO index..We are presently in a + AMO stage.. all this means is that the sea surface temperatures are above normal..

So now lets eliminate the years that were not +AMO . This would take about 1964 thru 1995 out of the equation.. So we eliminate the following years:

1970,1971,1974,1975, 1984 & 1989 . That leaves us with 6 years that were + AMO which were 1950,1954,1955,1956 & 2001, 2008. Again this would leave us evenly split down the middle with 3 warm winters and 3 average to below average winters…

1950 was a positive NAO

1954 was a positive NAO

1955 was a negative NAO

1956 was a negative NAO

2001 was a negative NAO

2008 was a positive NAO

So lets look at where the NAO has been recently for its running calculation..

 

As you can see the NAO has been predominantly negative so we would have to rule out the years that had a positive NAO and that eliminates from the list above 1950.1954, and 2008.

Ironically enough the three years that remain are 1955,56 and 2001 and the Arctic Oscillation those years was also negative!

So with the research above showing that we do indeed have a –PDO, –QBO, +AMO –NAO, –AO and a La Nina.. it only makes sense that you would look at the La Nina years and then look for the years that had the same atmospheric setup teleconnection wise in order to come to a logical conclusion for the Winter 2011-2012 season.

So as you can see by the above ..evidence lies very much in a colder and snowier winter. with the NAO and AO being the most important factors ..more important then the PDO & QBO .