This last November in Canada was a very cold one. At that time the jet stream was in advance on its schedule and was lower into Canada(not sure how it was on the other side of the globe at that point).
This was big news as it had not happened before as far as I know.
Now it seems that it might have split up in two, one part going way low causing all the cold up to Florida and the other part lower than usual causing this global freeze.
I would go for that explanation more so than the Norway spiral.
We are really at the mercy of this jet stream, if it does not come back to normal, we might have to get used to present situation and possibly worst, who knows.
http://squall.sfsu.edu/crws/jetstream.html
Big hello to you Northern Sanctuary, I hope your project is going great....