You are reading way too much into that...its basin wide, as it has been all long. Its a bit east biased, sure, but not a huge deal...all ENSO regions into la nina territory. As far as December goes, you are pulling a Judah Cohen in that you are over reliant on the polar vortex in your quest to garner forecasting insight. Yes, the state of the vortex is correlated to our degree of winter weather, but its not an independent variable, like everything else in weather. This is the biggest mistake I see with respect to long range forecasting. We can still have a good winter month at our latitude with a reasonably potent vortex because there exists a plethora of other nuances to consider....ie, what is the orientation of the vortex and where is it placed? Is it ultra strong, as in seasons like 2011-2012, 2019-2020, or is it simply healthy? Its the latter this year and its been elongated and stretched onto our side of the globe. Is the cryosphere allowed to generate in Canada? If there is a cold source nearby, where are going to see a gradient pattern, and I think we will.
December will end up fine for most of us.