Tuesday, July 31, 2012

2008-10, 2011-12 Southern Oscillation Index Values Similar

Values between the 2008-2010 Southern Oscillation Index (SOI) readings and 2011-present SOI readings are eerily similar. The 2008-2010 SOI values are above. The period begins with an SOI indicative of a La Nina, with readings between 10 and 25 in the early months of 2008. This was followed by a significant drop off into negative territory and a rebound into positive territory. The following year included continuous plummeting values of the SOI, with a reading approaching negative 20 in early 2010.

Now let's look at 2011-present SOI readings.

The timeframe in question began similarly to 2008, with an elevated La Nina-status SOI. An abrupt falling of the SOI followed, and a rebound into La Nina territory. Does this look familiar? If you're thinking of the graph above and its similarities, then you are making the right connection.

If we use 2008-2012 to forecast for the next year or two as the two graphs are markedly similar, one would expect an increasing El Nino, rebounding into La Nina as we move into 2013. I personally do not want to forecast that far out just out of confidence issues, but I find it very interesting that these two graphs are so much alike, only enhancing the general 2009-10 analog for the upcoming winter.


1 comment:

Mike Paulocsak said...

Hello Andrew.The 2009-2010 winter in the Ohio valley was a good one.We had three big storms in February 2010.The Mid-Atlantic and east coast also got hammered.It will be interesting to how this pans out.