I am always researching variables as they relate to winter. As most of us know having a negative North Atlantic Oscillation (NAO) during winter is key for big winter storms. In fact this pattern can even save an otherwise warm and mild winter due to other external factors.
As a refresher this image below represents a -NAO pattern..
Below I took five of the largest negative NAO winters (good for cold and snow) and subtracted five of the most positive NAO winters in terms of sea surface temperature anomalies.
The result is below..
Few key areas in the Atlantic. Notice the largest -NAO winters had warm water in the Caribbean, colder water to the North and then warmer water in the Arctic near Greenland. This is actually called the Atlantic Tri Pole and is a good precursor to a negative NAO winter (always other factors too at play).
Here are current model projection ocean temps for this winter..
Comparing the two, notice the Atlantic does not look as favorable for a Negative NAO. We would need warmer water near Greenland and that cold pool to drift a little more south.
However, look out in the pacific in the El Nino region. Notice in the top -NAO winters (first image) we had the warm waters more west and in the model projection they are more west as well. That is a favorable sign for a -NAO. What will the final verdict be? Too early for me to say, just showing you guys my observations as of now.
Find out more in my Winter 2016 Outlook coming in October!