It appears an extraordinary cold wave is going to occur the week before Christmas with life-threatening, travel disrupting, and extremely  e xpensive energy-consuming cold.  Since Thursday, December 8, I have been writing about a very cold period in store for the Lower 48 states starting this week. The major storm (see postings below) will pull a very  cold air mass from Siberia (where temperatures are -80°F) over the Pole, through Canada and into the USA.  While we usually do not associate heavy snow with extreme cold, that is a generality. With the right conditions, heavy snow and ice can  occur with extreme cold. I agree with the 8-14 day temperature outlook just issued by the National Weather Service.  Just how cold are we talking about? Here is a forecast temperature map from the GDPS global model valid 6pm CST on November 21st (the time on the map is UTC, ignore it). These are close to the high temperatures  of the day and they are below zero as ...