Wednesday/Thursday nor'easter appears too far south for a N VT hit but outlook looks colder through Xmas and beyond !

 Northern Vermont has gotten off to a slow start on snowfall for the season and as of December 14th, there is way too much bare ground even across the high country. With cold weather settling in across interior New England, the search is on for snowfall and if the big nor'easter confines its impact to coastal New England on Wednesday and Thursday, it will be a difficult pill to swallow. There's still a little time (maybe another upper air cycle of model data) for a late inning northward turn but clearly we are running out of outs and the odds are getting pretty steep.  As of midday Monday, the debate is revolving around when and where the strengthening winter storm will take a slight right turn off shore. The disagreement relates to about 100 miles worth of space and this leaves northern Vermont out of the possibility spectrum when it comes to heavy snowfall. There is a popular high resolution model that brings the storm far enough north for a 7-14 inch snowfall early Thursday but this same model is considerably more reliable when it comes to finer details inside of 36 hours and is unreliable when it comes to general details almost 72 hours out. That said, any storm of this magnitude is worth our attention.

 The jet impulse marking the arrival of our first serious outbreak of arctic air should bring 1-3 inches of snow to the high country around the MRV Monday night into very early Tuesday. Dry and more stable air will ultimately win out for most of Tuesday but even with sunshine, temperatures should stay into the teens during the day and drop below zero Wednesday morning. The same, dry, cold airmass is expected to maintain control of the weather across northern New England even if high clouds impact grey-out the sunshine. There's a 30 percent chance for a an inch or two of snow from the aforementioned storm and a less than 20 percent chance of something bigger that would involve a big northward shift in the expected storm track. Southern Vermont has a 60 percent chance of seeing a 1-4 inch snow but even there, the dry air will be a formidable obstacle to the incoming moisture based on what data is showing. 

Even with another whiff, the outlook for the remainder of December has good news...it's colder !! Although the jet stream in the Pacific is angry with the EPO index remaining positive, it is not indicated to be that positive. Additionally, the -AO/NAO combination is indicated to hold, likely for the remainder of 2020. I can't emphasize enough how this contrasts with what we saw for most of 2019-20. Not only was the AO positive, it was often very positive with the index actually moving off the chart on at least one occasion. We are also moving into the part of the season where competing indices are actually a good thing for snowfall in northern Vermont. I can feel the cynical responses even as I write this, but in a general sense, the holiday outlook doesn't look half bad as of today. 

Details remain a more fluid situation but appear as follows.  Dry, cold weather will continue to prevail through early in the upcoming weekend but some light snow is possible as early as Sunday and extending into the winter solstice Monday. There are hints of a more significant snowfall on Tuesday the 22nd but all of the potential snowfall (between Sunday and Tuesday) stems from polar pacific jet energy that will have limited access to GOM or Atlantic Ocean moisture thus somewhat limiting the big storm potential. Ensembles continue to show the possibility of a push of milder temperatures just prior to Christmas but this looks weaker and might not impact northern New England at all. Christmas and the days that follow all look colder and some accumulating snow is possible. The outlook today actually paints a picture that includes sub-freezing temperatures at least 90 percent of the time through the rest of 2020. That's a pretty good way to start any forecast and if we can lock that part in, natural snow will have a hard time continuously avoiding us.