Long stretch of sub-freezing temperatures begins Monday and although the pattern will never become extremely cold, we will get a sustained window of time to accumulate some snowfall. Certainly the largest of this pathetic winter season so far. A powerful clipper system kicks off the party on Tuesday spreading snow across all of New England. The storm won't gather any serious moisture until it interacts with the relative warmth of the Gulf of Maine and thus the heaviest snows will fall well east of Vermont. Nonetheless, the weather system will still be a dynamical and mechanical force even without serious moisture. Light snow should continue into Tuesday night and become snow showers Wednesday. 4 to as much as 8 inches of snow across the high country by late Wednesday should provide a nice wintry setting to build on. The storm will also ensure the continued dominance of colder weather which will continue through the end of the week
More light snow can be expected Thursday from a much more benign disturbance. Accumulations from this will be on the lighter side but after a dry day Friday the stage is set for an interesting weekend. The jet stream is poised for another serious amplification and there are two areas of shortwave energy within this larger scale pattern that will be focus for storm development. It is no surprise that models have been rather inconsistent regarding the results. Beyond a week, medium range models have difficulty especially when there are multiple playmakers on the field. Which player actually makes the play ? One potential storm Saturday appears to be a bit out in front of the main thrust of jet energy which appears more likely to rev up of the second potential storm Sunday/Monday. Another concern involves the position of the mean large scale trough in the jet stream early next week. Ensembles are generally suggesting it sets up a bit too far east for our total liking. It takes rain out of the equation but we don't want a potential big storm going innocently out over the ocean.
More "soft" chilly weather can be expected in the wake of any storm Sunday/Monday. This means that temperatures stay sub-freezing but will not categorically fall in the "below normal" range. A very typical outcome during such a strong El Nino. Another in the series of strong impulses in the southern branch of the stream has the potential to do something interesting during the middle of the week (January 20th) but 10 days out is way to early to get excited. It's just nice to know it's there. Beyond that, I expect the continuation of a generally favorable pattern. Not incredibly cold but productive due to a loosened Pacific Jet and an Arctic Oscillation on the negative side of zero. Ensembles restrengthen the ridge in western North America between the 23rd and 25th of the month giving me some confidence that sub-freezing temperatures could prevail through the rest of January.