The pattern seems to be setting up for another shot of Canadian chill in about a week to ten days from now. Computer modeling over the past couple of days has been relatively consistent in suggesting that we see the final rumination of the mild to warm pattern that dominated December and will dominate this weekend into early next week. One could argue...and frankly, I'll be the one to do it here, that the pattern has been in evolution mode the past week or so since December 23rd/24th and that the upcoming cold look is the full force of the change taking place. Temperatures on Tuesday and Wednesday, which were in the 20's both afternoons, were rather cold...so the pattern itself isn't going to shockingly "flip" over to cold from warm...we've been dragged into it and will get fully shoved into it later next week.
The way things look right now -- mild weather looks to hold serve starting Friday and continuing through Wednesday, with a storm system slashing through the East next week bringing rain to I-95, while phasing with a deepening trough from Canada. This interaction sets up the Euro's look for next Saturday (seen below), which is showing a reinforced look of cold over the Eastern US, with the coldest temperature anomalies likely in the Great Lakes or Midwest. Signs are suggesting that a cold blocking pattern sets up for at least a little while -- a period of at least a few days, perhaps up to ten days -- with temperatures similar to those we've dealt with the prior two days. In other words, real winter chill.
The GFS (seen below) from yesterday shows more chill loading up in Western Canada for the week of January 16th. This particular run of the GFS suggests in the lonnnnng range (out towards two weeks) that we get a secondary shot of cold air after the 16th, with cold reinforced in about two weeks' time. In terms of storm threats, it's still far too early to say specifically when/if we get snow but a colder pattern would be more favorable for snow chances...and considering we are now about the enter our snowiest six week stretch of weather on average the potential for snow should be there...eventually. Simply still too early to pin those specifics though.
Obviously much can change between computer modeling and reality but the warm November in December is a thing of the past...we'll swing on the pendulum for another week, perhaps longer...first going milder, then back to the chill we are about to escape from.