Opening day arrives. One of the earliest openings since the commencement of the blog and boy do we deserve it. We have been "killing it" on terrain enhanced snowfall, outperforming expectations almost every chance we get and thus we have, as of December 9th, gotten half way to last seasons total snowfall. Speaks both highly of the weather in recent weeks and poorly of the overall season last year.
Its been rather blustery late this week but for Opening Day we can expect some sunshine, lighter winds and some refreshing winter chill. Temperatures should start around 10 and climb up to about 20. Sunday will feature even lighter winds and a blanket of clouds in the afternoon should again keep readings within the vicinity of 20.
A garden variety storm system will make its way out of the Rocky Mountains Sunday and bring snow to the Great Lakes region as it does. In the last update we discussed the possibility of sleet and ice with this system as well as the possibility for a weaker all-snow event. The latter scenario seems more likely based on current indications. The low pressure center is expected to be relatively weak and make a rather efficient transition to the Atlantic Coast early Monday, squashing any thoughts of unwanted mild intrusions. Snow should begin Sunday evening and continue for several hours before tapering to flurries sometime Monday morning. Flurries and even some very light snow might then continue for several more hours. Model cross sections do hint at the possibility for some freezing drizzle in this time frame also but I don't expect this to be a big problem as of now. This looks more like a 3-7 inch event consisting of relatively dense powder when compared to the fluffy and convective terrain enhanced snow that has been falling recently.
After a rather tranquil and seasonable day Tuesday, the polar jet attacks ! As time passes, I think the effects of this arctic air will be confined to the northern states of the US and of course all of eastern Canada. Vermont's got plenty of latitude however and with the approach of the arctic front Wednesday, snow showers will develop. A burst of snow is also possible with the actual front later Wednesday but arctic air of this magnitude often has a very stable layer at the surface that can prevent a long duration terrain enhanced snow event. Readings could reach the high 20's Wednesday but remain in the teens Thursday and then fall below zero Friday morning. Not expecting much snow late in the week unless one of the Lake Ontario snow bands does something very unique which can happen from time to time.
I am more interested in the period surrounding next weekend, December 17th and 18th. Its still more than a week out and speculation can take on a life of its own, especially if you put wishcasters and powderhounds in the same room together. Come to think of it, I don't think I want to know what else might happen in such a room ;). Both major ensembles are indicating a much more significant area of low pressure exiting the Rockies either on Friday or over the weekend. Models diverge significantly on what piece of energy in the jet becomes the focal point. The Euro Ensembles though show a beautiful looking damming signature along the east coast which is one key ingredient for a major snow producer. We need a storm a decent track to make it all happen but I have good vibes.
The polar jet is expected to retreat during the following week but as I mentioned, arctic air should remain close by while re positioning some of its focus out west. As of now, I would not expect a big pre-Christmas thaw, something that has plagued us in recent years. If we get unlucky, we could see a bad day and some rainfall but the clashing of airmasses could also mean additional snows.