There is a wild pattern setting up across the United States with a major trough developing over the Rockies while ridging is pumping unusually warm air north through the Plains today, Ohio Valley Saturday and East Sunday.

The big player is a major storm system intensifying over the Northern Rockies heading NE, the backside of the circulation is pulling very cold air south out of British Columbia and Alberta while ahead of the front, temperatures are soaring into the 70s and may reach the 80s through the eastern Plains tomorrow. The sharpening thermal contrast is both intensifying the storm and the upper support, a major snowstorm is underway with blizzard conditions across Montana while heavy snows are falling across parts of Idaho, Wyoming, Utah, Colorado, extending west to the Sierra Range of California and up across North Dakota.

How much snow may fall? As you can see from the above graphic from The Weather Channel, as much as 1-2 feet is possible but this may be conservative, some upslopes may see 2-3 foot totals between last night and Sunday morning.

Daytime highs will hold in the 10s across Montana and 20s widely with 30s throughout the Rockies. Tonight sees lows drop widely into the teens  with below zero readings across parts of Montana despite heavy snows and strong winds continuing, this shows how cold the air is dropping out of Canada. On Saturday, highs may have a tough time getting out of the single digits with lows tomorrow night dropping more widely below zero.

Watch out for severe weather breaking out through the Plains Saturday, Sunday as the potent cold front slides east.

As stated last weekend, ridging that is now building over the Plains will migrate east over the next 2-3 days and by Sunday, highs will return to the 60s throughout the Northeast, 70s may get as far north as DC

By Monday-Tuesday, DC, Philadelphia and Trenton may see highs climb into the low 70s.