Weekly Long Range Update into Christmas Week
It looks like most of the Arctic air will remain trapped across extreme northeast Canada and up around the Arctic circle over the next 2 to 3 weeks as the Arctic Oscillation remains primarily in it's positive phase. See graphics below. Forecast model ensemble forecast for the AO into mid-December.

Typical winter pattern from the positive Arctic Oscillation (+AO)

My latest forecast model interpretation for the next several weeks, which takes into account the European and CFSv2 output.



By the way, the CFSv2 is going gangbusters with extreme warm anomalies throughout much of Canada into the first half of December with a very large area of +3 deg. C. or higher anomalies.
Despite the mild look to the pattern there will certainly be some cold shots into southern Canada and the northern U.S. from time to time, but more than likely they will be brief and not extreme. The best chance of seeing a few quick shots of Arctic air appears to be near Labrador.
I also took a look what is going on in the stratosphere over the polar region and I see no signs of any future high latitude blocking (-AO) through the next 3 weeks at this point. It's still early in the season though.
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