Winter Storm Possibilities

Great news for snow lovers.  The latest GFS and NAM have been showing a major snowstorm over most of our area with heaviest snow totals remaining along and north of U.S. Highway 30.  The catch is that temperatures will be only marginal as of right now for heavy snowfall accumulations.  Models such as the NAM are forecasting temperatures around here to be in the mid 30's, while some models such as the ECMWF are forecasting much colder temperatures during the snowstorm (if there is a storm).  Prospects for a snowstorm have only shown up in many model runs just recently and have been rather consistent with the NAM and GFS models.  Right now, both the GFS and NAM are the farthest north of the computer models, causing them to bring in more of a mix of ice and snow before changing to all snow.  If temperatures are as warm as what the NAM and GFS are saying, then expect a wet heavy snow to fall from the sky.  At the other end of the spectrum, the ECMWF has an all snow event with much colder temperatures allowing for a fluffier snow.  Since all three of these are very similar with this storm, a consensus of the models would bring this area a mostly snow event next week, with some sleet or freezing rain/rain mixed in.  While the exact timing of the storm is still in question, my current thinking is that snow will begin Monday night, then continuing through Tuesday night, with some sleet and rain or freezing rain mixed in throughout the day, with lows Monday night in the upper 20's and lower 30's, and highs on Tuesday in the lower to mid 30's, and falling throughout the day.  The GFS is not really consistent with its snowfall totals between its runs, but the latest run is showing rather exciting snowfall amounts (or what I would consider exciting) with most areas seeing 2-4 inches of snow, and some areas possibly more.  As for the NAM, well it doesn't go out that far to be predicting snowfall totals for this event, but it is predicting snowfall amounts of 1-3 inches Monday night, with more on the way for Tuesday.  This could be a pretty significant event so stay tuned for further updates.
As for the Christmas Day forecast, well, expect highs in the mid to upper 30's (pretty warm for this time of year) under partly sunny skies as well.  Won't be the best christmas because of the no snow cover, but it will still be fun.  Have a Merry Christmas everyone!

This map of the ECMWF 00z run is showing a snow event for the area.  Green colors indicate high relative humidity in the upper atmosphere, showing us where precipitation is likely to fall and the map with the low pressure centers on it shows us the position of storm systems and the position of the rain/snow line.  That rain/snow is the 540 line on the map, and on this forecast, the rain/snow line is well south of the area, indicating that most of the area will see snow.