Obviously my statement that I don't recall cold snaps like this or that the weather was different back then is probably reflective of getting older and perception of the world being very different when we were kids. That said, I can't explain it but I don't recall these -40 cold spells just like I don't remember the summers being full of wildfires. It's very anecdotal.
What I have read - and that is likely due to the increased focus on climate change both in academia and in news media these days - is that the warming trend causes the air streams that normally keep cold air circulating only in the arctic to break down. We will get more unstable temperatures and more extreme swings. Overall the trend will be warming, but the break down of things like the gulf stream from rising ocean temperatures etc. is what allows the polar vortex air to slip down to more southerly latitudes.
|