The key to understanding the atmosphere is to look at all of the influences that can control upper level patterns.  As you all know, I’ve been keeping an eye on the stratosphere.  

As you can see to the left, there was a short period of warming which developed just before a phase of the negative NAO, then the NAO went positive as the 30 MB temperatures declined.  

The data appears to indicate that the cooling has ended and we will be entering another minor warming period for the end of November.  Based on this potential, I think that we will be entering another phase of a negative AO/NAO pattern, which may develop during a period of a positive PNA.  What does that mean?  

I think we are looking at a pattern that will be cold and very active for early December along with the blocking needed to produce significant winter storms for the forecast area.  Several other meteorologist have also noted that model guidance in the long range are strongly suggesting a negative NAO to develop, which can be seen on both the GFS and ECMWF long range guidance.  In short, get ready for a period of winter weather to bring many locations a much whiter look.