The hopes of a white Christmas this year are riding on the shoulders of a disturbance that's projected to cross the Midwest December 21st. For 72 hours models have been in agreement that some sort of low pressure would evolve creating a snow risk. However, the degree of phasing and eventual track remain in question limiting the confidence of where the snow band sets up.
Yesterday all the major models were further south with the track producing several inches of snow over the majority of my area. Today, the latest guidance has inched northward and that's a trend you don't want to see if you're dreaming of an old fashioned white Christmas around these parts.
One thing I can say is that it's still more than 5 days until the onset of the event so the final outcome is not yet certain. It would not take much of a shift south to get my area back in the game. On the flip side, more phasing would mean a shift north and the fat lady is singing like a lark...it's over! The northward shift is more likely than one to the south so I"m not very hopeful. I've heard that fat lady way too many times in recent years.
The biggest negative/obstacle for my region against much in the way of snow is the fact cold will not be in place ahead of the storm. It's really tough to get much in the way of accumulations when you need to make that transition from warm to cold air. Usually by the time it occurs the brunt of the precipitation is off to the east and only a brief period of snow or mixed precipitation occurs before it comes to an end. This is a big concern for my local area and the primary reason why I expect the heavier snows will occur from northern Iowa into SE Minnesota and Wisconsin...perhaps just clipping my northern counties.
Keeping in mind the fact there's still room for change, here's the latest snowfall forecast from the GFS.
The EURO is even further north and looks like this.
The GEM/Canadian is the furthest north and leaves my area high and dry when it comes to snow.
Whatever happens with the snow, cold (maybe extreme) is coming this Christmas. The GFS shows this for lows, highs, and wind chills Christmas day. Yikes.
Lows Christmas Day:
Highs Christmas are about the same as the lows. In other words near steady temperatures.
Wind chills look to be a factor all day but they get serious Christmas night when readings of 30-40 below are forecast. Some chills in WC Minnesota are shown as low as minus 58! That's extremely serious and potentially deadly. Hopefully later runs ease up on the cold.
While there are details to decipher, it's apparent that at least the northern half of the Midwest has a good chance of getting white and staying that way through Christmas. We'll be able to get more precise on location and snow amounts in the next couple of days.
Of more concern is the potential for bitter cold and wind chill warnings and advisories around Christmas Day. This has the potential to be a big ticket item. Stay tuned and as always, roll weather...TS