Sunday, March 12, 2023

Bombing nor'easter will crush southern Vermont with heavy snowfall and bring 10-18 inches to MRG between Monday evening and Wednesday

I've been over-saturated on model data today trying to make sense of the upcoming storm and what it means for Mad River Glen and surrounding northern Vermont. There are two areas where question marks linger, one being the NYC metro area where there's continued uncertainty about precipitation type, and the other includes both the Adirondacks and northern Green Mountain region of Vermont where the question involves how far north the deep moisture can travel in this classic bombing storm. As of Sunday evening, southern Vermont and the Monadnock region of New Hampshire extending south into the Berkshires look like the sweet spot with some areas receiving more than 2 feet. I was a little nervous with what appeared to be another eastward shift this morning, but model data I trust the most seems to have settled on a decent result for the MRV, especially over the higher elevations. 

This has been a tough sucker to get a handle on, as this storm is expected to really begin strengthening Monday morning east of Cape Hatteras. The low pressure center will strengthen, but get stretched as one area tries to strengthen along the coast and another intensifies further over the open water. This stretching isn't uncommon, but man it doesn't make things easy, especially trying to forecast weather around New York city Monday night into early Tuesday. I'll attempt to simplify by saying we really are rooting for the low pressure on the western edge of this stretching (closer to the coast) to be more robust as it will help push the precipitation shield further north, west, farther inland and more over us. We would also really like this storm to consolidate and reach full maturation over Boston Harbor as opposed to south of the Cape and it is very close with model runs answering this question in multiple ways throughout Sunday. All that said, it looks like we can pull this storm close enough for a decent snowfall beginning Monday evening and persisting throughout Tuesday, Tuesday night and even Wednesday. The snowfall intensity will  likely be more intermittent verses areas farther south but the duration of snowfall over the high country looks very promising. As a storm such as this occludes, the moisture/precipitation shield will fan out and it seems probable we will receive some oragraphic enhanced snow extending into Wednesday, and all of this gets some additional assistance as the flow becomes more northwesterly off Lake Champlain, which it will during the day. I am keeping the range wide to account for this lingering uncertainty but 10-18 inches between Monday evening and Wednesday is my guess and it wouldn't surprise me if we fell outside of this range in either direction. I love the fact that this storm appears elevation sensitive and that we could get a long duration snowfall, but the eastern segment of this coastal low could try and slingshot the whole system out to sea quickly Tuesday evening and this still bothers me a little. 

Given the intensity of this storm, there are obviously other concerns relating to wind and snow consistency. The latter obviously impacts ski conditions but it also is very important for power outage risk as wet snow can take trees down on power lines especially during high winds. I think this will be an issue father south but our temps appear to be cold enough on the mountain to support a drier but wind-blown snowfall while readings will be just below freezing in the valley meaning a wetter snowfall (though not heavy enough to cause too many problems). Winds will be northeasterly most of Tuesday between 15-30 mph and more northwesterly Wednesday and even stronger. Sustained winds and gusts will be higher across the summits and although this is a decently favorable direction for operations at MRG, it's strong enough in other locations to cause some issues. Travel will be a disaster for a good part of Massachusetts, and the southern two thirds of Vermont and  New Hampshire Tuesday. I would not advise a trip from the Boston or NYC metro to northern Vermont during the day. 

Still looks like some warm afternoons are probably on Thursday and St Patrick's Day. Wet weather is possible Saturday but then it turns colder again Sunday leading us into what appears to be a mostly wintry week of March 20th-24th.

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