Forecast models Mr. Grinching potential big storm on Dec 22-23 (Thur/Fri) shifting track west and bringing ice/rain into forecast picture

We certainly got a terrific result with the storm both Friday and Friday night with two feet falling over the high country and some additional snow showers and flurries on Saturday. Though we are in the middle of a very favorable weather pattern, there is growing concern with our next storm expected to strike on Thursday December 22nd into Friday December 23rd. We've gotten a couple rounds of model data showing adverse results and we will need to reverse this trend very quickly to save a storm setup that appeared loaded with potential for several days. I'll discuss the details two paragraphs down but needless to say it has been very disappointing watching where forecast simulations have trended the last few days. 

Up until Thursday we continue our stretch of sub-freezing temperatures on the mountain and readings will actually inch toward the colder side each day with high temperatures up near 30 on Sunday and then dropping into the 20's Monday, Tuesday and Wednesday and perhaps only low 20's for a while on Thursday with morning temperatures in the single digits. Westerly flow on Sunday is capable of producing a few flurries and light snow showers but the setup will improve Monday with snow showers enhancing in the afternoon as winds become more northwesterly. Models are not indicating much of an accumulation and I would not expect one in the valley, but the mountains, General Stark, Lincoln, Mt Ellen could see a few inches. Tuesday and Wednesday don't appear to be totally bluebird but both should feature the most sun out of any of the days during the upcoming week. 

So I've been reading my nearly 2 year old daughter The Grinch That Stole Christmas and she doesn't seem to very fond of Christmas Trees vanishing up the chimney. As far as I am concerned however, old Mr. Grinch can have my Christmas Tree just don't give me a highly amplified inland cutting storm capable of flooding me with warmth. This is what's been happening to Vermont year after year and the curse seems to have taken on a special life of its own by defying a blocked weather pattern late in 2020 and yielding a Christmas Rain and threatening to do that again with the upcoming storm on the 22nd and 23rd. But before we all start crying in our beer (I've already kinda done that), keep in mind that we are working with more substantial amounts of cold air both on the front and especially rear flank of the storm. Even if the very dynamic low pressure center in question were to track over Syracuse, northern Vermont would be capable of procuring a decent front end thump of powder, limit the the freezing rain/rain period and receive some back end wrap around oragraphically enhanced snowfall Friday evening into Christmas Eve. If this were indeed the absolute downside of possibilities, I wouldn't feel too bad about the less than ideal situation. Late on Saturday evening, both the Canadian (GEM) and American GFS ensembles seemed to support such a scenario. That said, there have been several operational models released over the last 24 hours that have been suggesting the polar jet injection is just a steroid that simply over amplifies the whole setup, too early and too far west. The European model from this afternoon flooded much of eastern Ontario and all of Quebec with warmth and had the best snow over Madison, Wisconsin. As I mentioned, I've seen a few iterations of this on operational models run over the past 24-36 hours but fortunately the aggregated consensus of data has not yet been advertising anything that dire. 

I mentioned the other day how difficult it is for medium range models to get a handle on winter storms when a polar jet gets involved. The arctic, and the jet stream that brings it operates at a different speed and small changes in that speed can mean very different results. We are 5-6 days from this event and I continue to expect some additional changes. Highly amplified storms can be fun when the track of the storm is right, but in this case we would prefer a slightly flatter less robust storm. It's not looking promising we can keep the ice or rain out of the forecast picture in this setup given where data has been trending, but we still have some limited time to salvage the situation. 

Additionally, we still have several days of garden variety arctic chill in the wake of this storm though amazingly, after all the hype surrounding this weather pattern on social media, most of interior New England won't see any sub-zero readings from this. Parts of the deep south will see some impressively cold temps for a day or two thanks to the core of the cold getting pile-driven toward the Gulf Coast by this storm. The cold will come quickly and go rather quickly however and is unlikely to create too many problems outside of the winter storm's primary impact zone. As far as additional chances for snowfall after the 22-24th, nothing specific is showing up, but I expect the weather pattern to soften and this process typically allows for another storm to materialize. In this case it would allow our next chance to arrive in the time frame just before New Years. 

Beyond that there are clearer suggestions of a push toward a milder pattern with a tightening Pacific jet stream and a more zonal weather pattern. There are indications on the ensemble data of continued storminess which is encouraging as far as snow potential is concerned. By January we don't want a weather pattern to overwhelm us with arctic cold and thus a little mild can still produce decent results while a complete torch is something we would obviously no part of.