..Heavy-lake-effect snow downwind from the Lower Great Lakes and heavysnow from parts of the Central Rockies; snow from parts of the LowerMississippi Valley to the Northeast......There is a threat of rain/freezing rain over parts of the SouthernPlains to the Southern Appalachians......Temperatures will be 25 to 40 degrees below average from the NorthernRockies to the Plains, Middle Mississippi Valley, and Ohio Valley