Model data has been playing some Ring Around The Rosie over the past 24 hours but we still have a clearing picture of how this will play out. This is a tough weather situation for a model or a human to get a handle on since the precipitation producing low pressure center has yet to form and temperatures in the lowest 5000 feet of the atmosphere are so close to freezing, that differences of a degree can make all the difference.
If your sitting below 1000 feet, you might not be too excited with the forecast this weekend and I wouldn't blame you. Mixed precipitation, rain and maybe a sloppy accumulation on grass is not especially exciting. For the base of MRG (around 1700 feet) and upward, the forecast for snow holds and accumulations could be quite significant. The low pressure center in question will eventually form, strengthen and track right up through the Upper Valley. Temperatures are predicted to be rather marginal, ranging from about 32-34 degrees in the lowest 5000 feet of the troposphere. If you push that air up a mountain though, it will cool just enough to make the critical difference and that's what I think happens when precipitation commences around dawn Saturday. Temperatures will range from about 33 degrees or so at the base to maybe 29 or 30 at the summit which will make the snow a bit gloppy in nature. We can also expect near gale force east winds at the summit which, as some of you know is not a good wind direction for the single chair. That wind will actually subside later in the day and ultimately shift to a more westerly direction for the duration of the weekend. As for precipitation, we could see a pretty decent thump of snow during the midday hours. If I am correct with my assumptions about an elevation sensitive storm, 6-12 wet inches will be the end result. That said, if a period of rain or sleet (less likely) impacts elevations up to 2500 feet or above, it will hold accumulations down. We are very likely going to get a piece of the deep moist plume of this storm however even a gloppy accumulation can be put to good use as far as establishing a decent base is concerned.
With that part of the forecast transcribed, I can now move on to the even better part. The Sunday-Monday period is the best terrain enhanced snow set up we've had all year and this snow, on the mountain will be powdery even if valley locations hover above the freezing mark Sunday. The initial thump of wet snow on Saturday may be followed by a period of drier weather before these snow showers commence sometime Saturday night and continue through Sunday. The wind direction isn't ideal for MRG/Sugarbush and is better for locations farther north, but the moisture and instability are there regardless and I expect a decent additional accumulation of 3-6 inches on the mountain by late Sunday. That wind direction is expected to become more northwesterly Monday providing an additional window for snow showers, at least while the instability remains. Overall, this is a pretty good holiday forecast so long as you get yourself out of the valleys.
The snowfall doesn't end on Monday either. A clipper-like disturbance accompanied by a weak push of arctic air will bring snow back to Vermont Tuesday night followed by the coldest day we've had this month on Wednesday with temperatures struggling to get past 10 on the mountain. We then arrive at the less certain part of the forecast period, late next week. The question involves the presence of absence of a significant east coast storm and that question revolves around how much sub-tropical/southern branch jet energy/moisture wants to involve itself into this colder pattern. Looking at the models it appears to be a here today, gone tomorrow type situation which means I can't say anything conclusive. I can say this though, even without a bigger storm, some new snowfall is likely from another unphased clipper-like storm.
The end of the month continues to look chilly but a bit drier. The mean axis of the trough appears likely to set up over the western Atlantic Ocean leaving us on the less active flank of this jet stream feature. We would have to rely clippers, maulers and screamers out of Canada in this scenario but things can change beyond 10 days.
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