Winter cometh slowly 

Numerical Weather Prediction guidance is highly divided on what to expect for the next 2-3 weeks. There have been few signs of any sustained blocking patterns to bring substantial lasting cold. But the GFS does prog a negative NAO to come. There are some signs of a positive PNA developing which opens the window to more cold by next weekend and beyond. But whether it will come and go or stay and deepen its ice grip is not clear. As the European model shows the pattern breaking down and mild air returning in mid or late December, while the GFS deterministic model shows the same only slower and weaker but its ensemble is colder. However, the bias-corrected MRF (old GFS) is bold in its depiection of a strong +PNA ridge west trough east pattern locking in below-normal temperatures for a good chunk of the nation including much of the South and this is suported by the CPC objective analog guidance through the 14th and the Canadian NAEFS shows below normal temperatures through Dec 18th.

So while a cold snowy winter is not the forecast and I would not hold my breath for another white Christmas in Atlanta, opportunities for mischief from old man winter in the days and weeks ahead this month and next.