What a difference a day can make. On Monday, we saw record highs all across the eastern two-thirds of the nation, with over 400 record highs in December set. On Tuesday, temperatures began to fall as the month of December decided to actually make itself known. On a related note, the nation hasn’t seen much snow to start the month and we are well below normal in terms of snow cover. However, that is all about to change this weekend, as a large storm develops in SE Colorado in response to upper level forcing in place, as a large trough digs out in the western United States. With moisture in place, and the Gulf of Mexico open for business, this storm will likely be the precursor to future storms for mid to late December.
For the most part, we have seen a very mild November and early December, but temperatures will return to normal/below normal for mid-December after this storm moves through this weekend. An arctic cold front will dive south and eastward, bringing with it much colder air that has been trapped up in Canada for weeks. With this pattern change, the storm track, which has been predominantly to the north in Canada over the past month, will drop further south, bringing more unsettled weather to the eastern two thirds of the nation. In fact, much of the central plains states have been dealing with an exceptional drought, and hopefully, a more active with pattern will bring much needed precipitation to the region. The image below can give you an idea of just how dry it has been.
The one thing that sticks out is the lack of drought seen in southwestern Texas as compared to last year at this time. Unfortunately, where one place receives rain, another place often doesn’t and that looks to be the case over much of the front range and central plains. If only the central US could pick up the type of rainfall that the west coast has been seeing. We’ll have to wait and see, but as the 6-10 day precipitation outlook shows, the central part of the US won’t be seeing much in the way of serious precipitation until late next week.
Now, I realize I may have drifted off topic slightly, so, here’s a look at the forecast for the snowfall. Right now, it looks as if much of the snowfall will remain north of the Interstate 80 line. Much of the Dakota’s, Minnesota, Wisconsin, and Michigan will see the bulk of this snow from this storm, however, on Monday, if temperatures are able to cool enough into northern Illinois and Indiana. The first measureable snowfall of the season is on tap for the Minneapolis Metro, and Chicago could even see a couple of inches by the time all is said and done. In fact, according to long time Chicago Weatherman, Tom Skilling, Chicago is on track for a record longest period without measurable snowfall. It would tie the record (280 days) on Sunday, and perhaps break the record (281 days) on Monday. However, it is possible that Chicago could see measurable snowfall on Sunday, but the most likely chance of measurable snow would be more likely on Monday.
The following graphic depicts the probability of seeing snowfall with this upcoming system, both Sunday night and Monday. The heaviest snows will likely fall in North Dakota and central and north central Minnesota on Sunday. I believe these areas will see about 4-8” of snow by Monday. Minneapolis should see around 3-7” of snow, with places in the northern metro seeing the totals on the higher end.
Those colder temperatures will follow the arctic cold front, bringing an end to the mild weather we have been seeing so far in December. I’ll bring a few updates on the storm as it evolves tomorrow and Saturday.
Until next time,