Saturday will bring a return to colder temperatures but the stars are aligning for a terrain induced powder event and perhaps one of the better ones we have seen this year. The return to colder temperatures will not eliminate either the low level moisture or instability. The key in these types of events which are is for a minimal amount of directional shear in the lower part of the troposphere and for a deep layer of instability extending hopefully ten thousand feet up in the atmosphere. Deep is a relative term because ten thousand feet would not be considered a deep thunderstorm cloud but such a layer in the winter can produce a large amount of perfect skiing powder. Saturday appears to be a day where all this can happen. Light to moderate snow should persist through a good chunk of the day and a fluffy 5-10 inches is very very possible. Such a snowfall would be very very very much needed in light of how firm the mountain will be as temperatures turn colder after the recent warmth.
The snow should be over and done with for Sunday and temperatures will remain in the seasonable category but the talk of more snow will remain as a more organized storm system promises to impact the region early in the holiday week. This is a storm which pummel the mountain west with snow before exiting the eastern Rockies Sunday. The storm will be a front-runner and will have a warm front and associated overrunning surface extending well over 1,000 miles east of the low pressure center. Given the expected track of this weather system, it is the right kind of storm to deliver another needed dose of snow if we can avoid any mid-level, above-freezing intrusion capable of changing precipitation to that dreaded icy mixture. For the time being, it looks like that will happen as snow should begin in the pre-dawn hours Monday and continue into the day. Models are not indicating a huge accumulation but 3-5 additional inches would make for the second powder day in 3 days.
The mountain will face more adversity later in the week. Remember, are indices are still decidedly unfavorable and this leaves the door open for another push of warm weather as the week progresses. Both Tuesday and Wednesday look dry and seasonable with temperatures ranging between 10 in the mornings and 25 in the afternoons. Tuesday will feel colder thanks to blustery northwest winds. Later in the week however another in a series of systems in the mountain west will move east and may try to take the unpopular St Lawrence Valley route. This is hardly a settled issue and the American GFS model has indicated that the system may track farther south and keep winter in place across northern Vermont. A subsequent update will have to tackle some of these key unknowns but for now I would guess on a slight warm-up for Thursday followed by mixed precipitation Thursday night into Friday.
The pattern beyond Friday continues to look incredibly energetic across the west as a continuous series of vicious storms hammers the mountain west. It will likely create an epic powdery scenario for the Central Rockies and will continue to make it challenging for eastern areas. This being said the recent ensemble members are generally showing a colder signal when compared to the upcoming week hopefully indicating a storm track that will be a bit further south.