Ha, not an ice glacier, but a cold air mass that behaves almost the same.
That air is incredibly thick, like ice. Nothing can penetrate, not even tropical plumes from the Atlantic.
Slowly it comes down, and is stopped by the Great Lakes. They are right now pouring out a tremendous amount of heat energy as they freeze. But the mass of zero energy air just sucks it up and moves down.
Such drama! I'm writing a fantasy with a good physics engine. :) Can't wait for the next headlines:
Freezing spit caused by climate change
ps. and you can see that the black zone is well below average, but the east coast is happy.
pps. and it looks like another huge east coast snow storm coming up, caused by climate change.