Thanksgiving for me tends to start the period where the atmosphere and the upper air pattern begin to transition into what will be the winter pattern. It seems to me that this time of year we see a morphing of the upper air jet stream which will eventually lock in to what will be the winter. What that pattern is we don't know yet. It might be the one we have at the moment with blocking combined with a fast west to east jet across the US with little amplitude. Cold shots come in and out every couple of days followed by brief warm ups. That is what we have at the moment. There has been a lack of storm activity across most of the nation for the last few weeks. Right now there is no sign of this part of the equation changing.
One of the interesting things about the loop of the temperature anomaly (below or above average) map is that there is a large part of the Northern Hemisphere that is showing below average temperatures. The other interesting factor is that the polar region is warmer than average which argues for a continued displacement of the jet stream south of average. This is quite a change of the prior 2 winters and continues to argue that the atmosphere is "normalizing" to some degree....READ MORE AT http://www.meteorologistjoecioffi.com/index.php/2017/11/20/seasonal-upper-air-pattern-transition-underway/