Snowfall potential is "eye opening" on Monday even after all the heavy rain and wind late Sunday.

There's certainly some bad news to discuss in this update. We are not looking at a particularly "arctic" outlook as we move toward the winter solstice and  Christmas holiday and we have some heavy rain to deal with in the short term. This follows what was both a successful and early (by normal standards) opening day at Mad River Glen. But with the bad news out of the way, I can focus on the positive and surprisingly positive in the case of this upcoming storm, a situation that I had pretty much written off as a disastrous outcome for the northern Vermont high country and all of its early season snowpack. 

Saturday still has a tranquil outlook and although clouds are expected to increase throughout the day, visibility should remain outstanding and the lighter winds and 30-40 degree temperatures should rank it pretty high on the comfort scale. The early part of Sunday also remains dry but with higher winds and milder temperatures. The rainfall will begin in the afternoon making it a wet end to the first full weekend of skiing at MRG. 

Here is the latest regarding the evolving situation with this upcoming storm. As expected, an initial primary low pressure center is taking a miserable trajectory, and appears headed toward the southeast part of the Hudson Bay. It tracks so far north of us, in fact, that it will actually lose some potency and ability to a continuous driving force of weather conditions throughout the storm. Over the  last several days, models have been hinting at additional waves of low pressure developing along the temperature boundary with the track and strength of these lows having a big impact on results for northern Vermont. We haven't reached a complete consensus yet, but there are increasing indications of a low pressure area taking shape east of the Appalachian mountains and tracking through central New England and then off shore north of the Cape early Monday. This would certainly bring additional moisture and enhance the heavy rain and wind Sunday evening which we kinda already expected. The expected track and developing strength of this storm however will pull cold air into Vermont quicker and potentially cut down the period of heavy rain over the high country, changing it to snow in the predawn hours Monday. A very favorable wind direction would then allow snowfall to continue through much of the day Monday, falling in powdery fashion after initially changing to a wetter snowfall. The rain and wind will do a lot of damage Sunday evening but the snowfall could be significant with an elevation sensitive 3-9 inches falling by late in the day Monday. Some uncertainties need to be ironed out as always, but if nothing else, I'll appreciate the ability to keep our mountains white for another week if we can pull it off. 

Like the first full week of December, the 2nd is expected to also feature generally wintry temperatures, but free of significant precipitation after Monday. Sunshine should return on Tuesday with sub freezing temperatures while some clouds and some very light snow are possible on Wednesday. Warmer air will try and work its way into New England later Thursday into Friday, but I think the milder temperatures stay west of Vermont for the upcoming week. 

Those aforementioned areas farther west will be consumed by Pacific air as we get to later next week  thanks largely to the loss of high latitude blocking which can be seen in the forecasted Arctic Oscillation index (AO) late next week. The Pacific is also getting angrier, but not overwhelmingly so, with the EPO turning unfavorable through the middle of the month but then neutralizing beyond that. This theme is actually evident in the AO index which also begins to improve or at least neutralize after the middle of the month, The problem after the middle of the month will be finding a mechanism to bring the cold arctic air south into mid latitude North America with all this neutrality. I have my doubts we can do it in a meaningful way before the holiday. The storm possibility is a different animal however. There are indications of a potential storm around December 18th (a Monday) and a minimal amount of leftover cold in eastern Canada. Can we mix those two things together and spin up something significant ? Maybe. The lack of strong arctic air also doesn't guarantee a blowtorch either even if  I would place my money on above normal temperatures through Christmas.