Thursday, February 13, 2014

Valentines Day Storm 2014 and all it's goodies

Snowflakes are flying across Vermont so more or less, the party has started. Even as we have inched closer to the event time, high resolution models have struggled with this relatively compact storm. This is understandable since there are some rather intriguing intricacies. Most importantly, it is a narrow area stretching from eastern Pennsylvania, to the Catskills of New York northeastward to the spine of the Green Mountains that should see the best snow. A few days ago this seemed possible with some loose consensus suggesting such, now it seems likely.

The biggest concern I have had and still have relates to the play by play during the storm. Radar imagery as of Thursday afternoon indicates an area of heavy snow moving northeastward through New England, behind that a large dry slot where no precipitation has fallen. This initial batch of snow has been very impressive dumping 3 and even 4 inch an hour snows from eastern PA to much of Mass but the strengthening low pressure responsible for this is moving a bit out in front of the deepening upper air support. This essentially means that MRG and surroundings is in store for an initial burst of snow Thursday afternoon. During the evening and into the early part of the overnight some dry air could get entrained into this initial conveyor of moisture resulting in a several hour period of lighter, less than 1 inch per hour snow. This deepening and very intense and quite closed piece of upper air support will ultimately win the day. Almost like a puppy on a leash, the aforementioned jet stream feature will give our winter storm a yank and prevent it from advancing too far to the northeast. In the end, a much more consolidated low pressure center will explode near the small strip of New Hampshire coastline to sub 980 mb. The associated precipitation shield or snow shield will likewise intensify. Some of the higher resolution simulations in the last 12 hours have really driven this point home. The snowfall intensities in the pre-dawn hours are indicated to be almost historic and in some cases really hard to believe. Take what is indicated and cut it in half and we could still see 2-3 inch an hour snowfall rates for a period of about 3 hours right at or just before dawn Friday. With that said, I am all in for our 15-30 inch storm total with the snow tapering to flurries in the afternoon. 

A couple of other things that should address some emails and other FAQ’s.

1)    I would not be surprised to see a minimal amount of sleet in the overnight hours Friday. There is a small near freezing layer in the lower troposphere that would only be an issue given very light precipitation. Once our bombogenesis is underway early Friday morning, it is all heavy snow all the time. 

2)    Snow consistency should stay of the powdery variety although at least initially, it will be of the denser powdery variety. By Friday morning, the snow should become more fluffy thanks to a more favorable dendrite growth environment in the later hours of this storm. Temperatures will be in the 20’s during most of this event but should stay far enough from 30 to prevent too much in the way of wetness in the snow. 

3)    This is a big one and I might get in trouble for speculating but what the heck. With any “bombogenesis” there will be wind, lots of wind. Vermont will be no exception. Winds are expected to be very strong particularly early Friday. As far as the Single Chair goes the wind holds are primarily associated with a prevailing east wind. The wind will be ferocious, gusting to 50 at the summits but it will be well north of east in direction, primarily north and then northwest later Friday. I am not making any promises and there are probably guys on the mountain that no more than I do about it and if they feel the need to chime in and scold me please do so. 

We also have another weather system Friday that will ultimately track slightly east of Cape Cod. It’s reinforcing area of upper air support however should mean additional snows Saturday, several inches I think. 

Lastly, this should be one of the best weekends at MRG in a few years so please get out there and get some. That being said, stay safe on the roads. The driving Friday morning, particularly early Friday morning, will be awful with low visibility, blowing snow and drifting on the roads. Plan around this if you can and please enjoy.

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