Legendary forecaster Joe Bastardi writes on Twitter: (and provides graphics to back it up)

Coldest Christmas with most widespread snow over since 2000 IMO.

GEFS Christmas temp anomalies vs 2000, and enemble snow before that.

Impressive for an ensemble that far out.

This is what the most reliable forecast model (ECMWF) shows for surface temperature on Christmas Day:

Here is the Climatology:

And here is what the forecast model GFS shows for snow on Christmas Day – snow as far south as Louisana and Houston Texas:

Images courtesy of WetaherBell.com