Friday, November 24, 2023

November to finish wintry with some wet snow early on Monday and chances for fluffier snow after that !

I tried not get overly distracted with short term weather when constructing the seasonal outlook, but I am free to do that now. There have been a few El Nino events in recent years that have featured a blowtorch December and I am feeling better and better about the notion that this will be different. It certainly appears very different in the coming week with plenty of winter weather to talk about and a potentially decent event to start the upcoming week. 

Some early season arctic air enveloped the state of Vermont as of early Friday with snow showers dusting much of the northern Vermont high country. Earlier this week, temperatures dropped to 10 degrees in a few spots and clearing skies and slackening wind speeds will allow for the same to occur by Saturday morning. We can then look forward to a nice early season winter weekend with healthy amounts of sunshine and near 30 degree temperatures on Saturday followed by a cloudier though still a good visibility Sunday with readings climbing into the 30's. 

A couple of weather systems now appear ready to converge and consolidate into a respectable storm by Monday, November 27th. The cold air which is firmly entrenched as of Friday will become a bit stale by the end of this weekend temperatures in the lowest several thousand feet can be called "marginal" as a storm begins this consolidation near the Jersey shore. For now, I am of the opinion that our little section of Vermont will be on the right side of this marginal classification, but it's a close enough call to be impacted by any additional forecast changes so stay tuned. This means that snow should begin in the Mad River Valley late on Sunday night and continue for several hours into Monday. This storm appears garden variety in nature and won't reach a peak maturation until most of the snowfall has left us. We also have to leave the door open for alternative types of precipitation Sunday night, but again, I am of the opinion we can minimize this. If you live in the Champlain Valley however, I certainty wouldn't make that statement. 

We have another surge of early season polar air in the wake of Monday's storm and with it comes a really impressive pool of low level instability. Whether it be the Great Lakes, Lake Champlain or even the largely unfrozen Hudson Bay, all are capable of providing moisture in this type of environment and it gets deposited as snowfall in the Vermont high country. For Mad River Glen and Sugarbush, the amount of snowfall is highly dependent on the wind direction. Northwesterly flow can produce really impressive snow totals while westerly flow helps out areas like Stowe, Smuggs and Jay Peak more. Models agree on a mostly westerly wind Monday and then we try to turn those winds more northwesterly on Tuesday though models disagree on how much. Still we will have the opportunity for some substantial additional snowfall especially on Tuesday. My early guess on all of this is a 3-6 inch dense and wet snow Sunday night and early Monday and 2-6 inches of additional fluffier snow later Monday into Tuesday. 

Model simulations, for the time being, are bullish on a clipper system providing some additional snowfall Wednesday night into Thursday but the clipper has been tough to bet on in the longer range outlook so I would anticipate expectations to evolve over time. Subsequent to this is some indications that the cold will soften for the first few days of December but this appears temporary as the NAO index is expected to fall. Indications are that the jet stream at high latitudes will be somewhat blocked for the first full week of December. A current face value snapshot does not suggest an overwhelmingly cold first 10 days of December, but playing fields appears inviting for an early season winter storm and there have been indications of such on a few of the longer range model simulations.

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