With the past few days of computer model runs, forecasts are coming into agreement that colder, and potentially snowier weather is on the way. While colder temperatures and snow showers are likely this weekend and early in the week, this will only be brief, as temperatures will moderate once again above normal by the mid to late portion of next week. However, this appears to be only transient.
Models are now beginning to show much colder weather infiltrating into the United States beginning in the 8 to 10 day period. [January 10th through the 12th]. Interaction with a disturbance in the southern stream will likely result in some sort of storm system moving from the Deep South off the coast and developing as a potential coastal low. After this disturbance, the northern stream [polar jet] will begin to dominate again as blocking begins to develop across high latitudes. A lot remains to be seen with this storm system [the Deep South/potential coastal storm], as it is only one possible solution, but even if this storm system does not develop, a fresh wave of Arctic air should move southward out of Canada and engulf the area soon after. And given past scenarios where this has occurred, there's at least a decent chance some areas will get accumulating snow out of this, whether it is from the southern low or from the weak clipper system that brings the cold air out of Canada.
At the same time, however, it is uncertain as to how long this wave of Arctic air will last. Given the depiction of the event on ensembles and operational model runs, it looks as if it as the potential to last for at least a several day period if not longer. Even when the coldest of the air leaves the region, it is still very likely that temperatures remain near or below normal for the remainder of January, with only a few days of above normal temperatures to end the month [it is possible that we see another transient warm up ahead of another Arctic wave as we head towards the end of the month].
Hopefully I'll be able to post a more detailed discussion of the situation later tonight or tomorrow. Until then, I'll just end the post with the 06z GFS solution for ten days from now [shown above]. This image is depicting a massive Arctic high pressure system sliding southward out of Canada, bringing a round of snow to the Central Plains with the associated clipper [which very well may give a good portion of the Ohio Valley a snow event].