Saturday 9 June 2012

My Analogs For Next Winter


 Starting to think about possible/ best analogs for next winter. Here is a chart I created which shows the correlation between this year and possible analogs I looked at. I gave every year a rank for each category (ENSO,PDO,AMO,PNA,SOI,EPO,QBO,NAO/AO). I gave a rank out of 2 for the PDO and AMO. The ENSO was out of three given 1 point for each of the following 1) West/central based nino 2) Year coming off of a double nina 3) A Weak to Moderate Nino from +.5 to +1.5. I gave a score out of 1 point for the rest of the categories and added up the totals on the right. I left a space in the chart between the SST related indices and indices not related to SST's. Hope you enjoy it!
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My Analogs:
The analogs I chose were based on ENSO,PDO,AMO,QBO,PNA,NAO,EPO,PNA and SOI. 2009-10 had the closest correlation, matching almost perfectly with PDO,AMO, ENSO and SOI. I double weighted it. 2002-03 was close with regards to the AMO,PDO and ENSO although not perfect. I also looked at 1976-77 which was the closest with the PDO but had a cold AMO. It came off of a triple nina (not double) but was west/central based and moderate strength. SOI was close and so was the QBO. 1972-3 was close with regards to enso position and it did follow a double la nina. The problem was that it was too strong compared to most forecasts (peaked at 2.1). SOI was very close and the QBO shared similarities as well as the MEI. If the PDO stays negative i will double weight it but for now i will leave it out. I looked at 1957-8 as well which was the second closest analog following 2009-10. PDO and AMO close, ENSO not as close but similar (more east based). SOI and NAO similar as well. I looked at 1951-52 which was similar to 1972-73 which both had a cold PDO and no warm spike for the winter like the other analogs had. If the PDO does indeed stay negative then 1972 should be counted twice but for now I am assuming it will spike positive based on current SST patterns so I am leaving it out. I will include 1951 due to its similarities. If the PDO stays cold I will double weight 1952 as well. I chose to look at 1965-66 but realized that it didn't share many similarities unless the AMO goes negative which is unlikely. I left 1966 out but will be watching the AMO. If it does go negative I will double weight 1976. 


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If PDO remains negative my analogs will look like this:

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For now we just have to wait and see what plays out as we get closer to winter.

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