As is so often the case, exceptional cold in the Eastern United States is being offset by exceptional warmth in Alaska and Western Canada. The warm spot yesterday in Canada appears to be Yohin, in the Northwest Territories, where Thursday's high was 58 degrees...in the Eastern United States, that was equivalent to Thursday's high in Central Florida!
This map of record temperatures (record warmth in red, record cold in blue) across the globe shows record cold in the Eastern United States, and record warmth in Western Canada and Alaska.
This see-saw reaction comes as the jet stream - the fast river of air aloft that steers storms and separates warm air to the south from cold air to the north - features a large "trough," or dip in the east, and a "ridge" or bump in the west:
This atmospheric setup is expected to continue for the next couple of weeks.