Not a ton of Christmas cheer in this update as we continue to fight a worsening winter weather pattern

Our forecast picture took a few uppercuts over the past few days. In the big picture, the prevailing negative fundamentals, the biggest of which being an AO and EPO index continuing to gain positive strength, are finally playing a stronger role in the regions weather locally and the forecast going forward. Rubbing a little salt in the wound is the forecast for late week which provided us with a bit of a head fake over the weekend. As of now however, much of the light snow that was beginning to appear likely Thursday night appears gone. We will have sub-freezing temperatures, good visibility, tolerable amounts of wind and some sunshine both on Xmas and on Thursday the 26th, but any light snow on Thursday night appears inconsequential (or end up falling as a wintry mix) and the milder temperatures which appeared to be only a miner threat for Friday, now appear likely with temperatures across much of the high country climbing above freezing.

Critical questions and potential problems have arisen after a tranquil Saturday the 29th. There are two major systems that could impact the east coast between Sunday 12/30 and Friday 1/3 and there are justifiable concerns regarding the first of these storms given the lack of arctic cold support. Both warm air and a lot of moisture are expected to surge northward ahead of an advancing area of low pressure Sunday in the Great Lakes region. The eventual trajectory of this storm remains a question, but if the storm tracks north of the St Lawrence Valley, it will be a disastrous wash-out across the entire state Sunday night into Monday. There are indications that the low pressure area in question travels on a more southern route, potentially re-energizing  itself off the eastern seaboard. This would be a much better result but given the lack of available cold, even this result might include a bit of rain late Sunday at the onset of this event. Though colder weather is expected to return to Vermont Monday, it's Pacific Ocean air and will thus consist of well-above average temperatures. Lingering amounts of both moisture and instability could set the stage for a decent period of snow Monday but such an occurrence would be better given the latter more southern track of this storm. Either way, snow showers should persist into at least early Tuesday - New Years eve.

The longer range outlook is getting double-whammie'd by the very unblocked jet stream in the Arctic and a corresponding tight and ferocious jet stream in the Pacific (positive AO, EPO). A typical Vermont January is certainly capable of performing even in a marginal pattern; in fact, sometimes the marginal pattern outperforms a polar vortex type scenario where storms and moisture are suppressed too far south. This double-whammy is tough to overcome however, even in Vermont. If there is anything to hang our wintry hats on, its the fact that much of the most intense arctic air across the northern hemisphere will be positioned on the North American side as opposed to the Eurasian side. Though much of it will be across Alaska and NW Canada, perhaps some can find its way into select northern U.S. climates such as the interior NE. That's the positive spin admittedly but there's a negative result to this equation consisting of a forecast dominated by a much stronger torch for the first half of January. Again, that's not the indication yet but it's certainly a risk.

In the meantime, that 2nd storm discussed 2 paragraph's above appears to have an impact period between January 2nd to January 4th in Vermont if at all. Though it appears to be a colder storm for now, and a deeper east coast jet amplification, a lack of arctic cold will keep temperatures on the above side of average. We just have to hope that the lack of influence from the polar jet stream might provide the opportunity for more action along the east coast of the cyclogenesis/bombogenesis variety.