El Nino is really doing a number on December winter weather this year, and as a result most of the eastern 2/3 of the U.S. will not have a white Christmas. But for those in the western U.S., a series of Pacific storms fueled by El Nino and continuing intrusions of Canadian air will result in widespread snowcover, as seen in the latest forecast snow depth on noon of Christmas day (graphics courtesy of Weatherbell.com):

Forecast snow depth as of noon 25 December 2015, from the Dec. 21 morning run of the NWS GFS model (graphic courtesy of Weatherbell.com).

The corresponding forecast of temperature departures from normal at the same time reflect the expected warmth in the East, and cold in the West on Christmas day:

forecast temperature departures from normal for noon 25 December 2015, from the NWS GFS model.

In the latter plot, note that temperatures will be running as much as 30 deg. F below normal in the West, but as much as 30 deg F above normal in the East.