The weather we have seen during this back half of December 2021 can be described as La Nina to the extreme. Cold, unsettled weather over parts of the west coast with snow in the mountains, extremely mild weather along the Gulf Coast and southeast U.S. and lots of cloudiness and marginal precipitation events in the northeast. Though we may have successfully retained a little sense of winter in northern Vermont, it hasn't been much of a consolation prize especially considering recent underperformance and another wet weather event on a holiday weekend. This is classic La Nina however and if we can just move the battle lines 100-200 miles to the south, our performance would improve dramatically.
Much of the southeast is finishing the warmest December on record and the ridge responsible for much of this weather continues to push weak, disorganized surface features in our general direction. These have been difficult to predict and have been under-delivering as I mentioned above. Some occasional light snow is still expected both Thursday and Thursday night but accumulations appear insignificant. Meanwhile the weekend weather event will begin to take shape as a stretched area of low pressure along the already established southwest to northeast temperature boundary. The first area of low pressure will approach New Years Eve and we will thus see another day of cloudiness and some light afternoon/evening snow eventually giving way to some freezing rain or drizzle by early New Years Day. This initial wave is weaker but is nonetheless critical since it will ultimately track well into Quebec and allow milder air to infiltrate the critical levels of our lower troposphere ahead of the primary weather producing storm.
I had hoped that some low level cold could make a push southward on New Years Day keeping sleet and snow in our equation for the weekend. We've gotten some good news as the track of this stronger area of low pressure appears farther south, perhaps tracking right through the heart of central New England but the cold ingredients are behind the system making snow a difficult ask. Temperatures on New Years Day are likely to hang out near or just above the freezing mark though it does look like we will keep much of the ski day dry though it will stay very overcast. Rain and a few pockets of freezing rain are likely to arrive during the evening New Years Day (Saturday) and continue into the overnight. Perhaps we can keep the rain on the lighter side and minimize the amount of total wet weather but whatever falls Saturday night is not likely to be good. All might not be lost with this storm however. Energy with this storm is eventually expected to consolidate around the trailing area of low pressure and if that passes to our southeast, another area of precipitation later Sunday into Sunday night might still start wet but finish as a period of decent snowfall before Monday morning. We need another few rounds of model data to sort through some of those details.
We do know that the first full work day of 2022 (Monday, Jan 3) will feature wintry temperatures with readings generally holding in the teens during the day and falling into the single numbers during the overnight. Flurries and snow showers are likely during the day Monday but we should also see some intervals of sunshine and we haven't seen much of that this week and don't expect any this weekend. More sunshine and even better visibility is then expected to Tuesday accompanying some very typical January chill. The cold weather is likely to continue into Wednesday before temperatures moderate ahead of another system likely to advance into the Great Lakes. The late in the week period between January 6th-7th again appears marginal with milder air attempting to push northward into New England. We could get a better result ahead of the Jan 8-9 weekend but could also see another mixed bag of weather.
On the state of the weather pattern more generally, there are some aspects you have to like. The jet stream in the Pacific through much of early January appears relatively loose and combine that with the blocking structure in the Chukchi Sea region of the arctic and cold air will assuredly push southward and impact much of the United States, especially the northern half of the country. Along the east coast, it's just a question of warding off the negative effects of the pesky Nina southeast ridge. I would expect at least some snow to accompany the inbound arctic air around the weekend of January 8-9 (perhaps as early as January 7) and this will be followed by several days of below normal temperatures. Interestingly, ensembles indicate that the southward moving polar vortex will bounce (for lack of a better word) off the southeast ridge and eventually land in eastern Canada. This would place Vermont in a pretty good spot for winter weather in the middle part of January but the wait has been long and agitation is understandably high (I know it is for me).
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