Last winter was dominated by these guys, and it is starting early. Dust off your furnace!
Although there is a big cold front all over North America right now, a true air glacier is defined (by me) as being total clear of any precipitable water in this chart. It is just cold, dry air.
So, get out your lumps of valuable coal that Santa gave you over the years, and stay warm.
ps, and as predicted by me, the super warmies are shrugging their shoulders, and saying "Who knew?"
Noooobody saw it coming.
pps. when this starts hitting the money areas, the tv guys will start the whole Polar Vortex thing again. That's when the Polar Vortex fairies let go of the cold air cows. That action is 50 miles up, with an air density of 1 thousandth of the surface. So, we have the equivalent of soap bubbles stopping a raging river.