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Wednesday, December 17, 2008

A big 1-2 and possibly 3 punch combo promises powder and lots of it in the week before Christmas !!

Hard to imagine a better Wednesday evening blog entry. Two strong weather systems lead the headline and both are going to provide some powdery goodness over the next 5 days and a possible third within a day or so of X-mas. And for those waiting and worrying about the skiing for Christmas and beyond, the sum of the snow from these storms will at the very least sure up the base and ensure that a healthy percentage of the mountain will be skiable.

The Players
Arctic air which continues to cover the greater majority of Canada is proving to be a potent force and its influence will overwhelm the more unfavorable teleconnections driving the global long wave pattern. With that said we are going to get some support from the development of a very important long wave feature over the next few days. This feature is often described in meteorological classrooms as a "jet max" or an area of "confluence" and it describes a zone where the jet stream is flowing west to east at a very intense speed. When such a jet max sets up near Newfoundland, as this one will, it can produce a very snowy result in the upwind region including New England. The effect of the "jet max" allows very cold, very dry air in eastern Canada to drop southward into the northeast. As the atmosphere saturates with the approach of a weather system, the very dry, very cold air keeps the effective wet bulb temperature very low and expands the area of snowfall over New England. This particular "jet max" will ultimately combine with a manifesting split flow situation in the Rockies to produce one of the snowiest December weeks since 2002.

Storm #1
The first storm will track quickly out of the southern Rockies and into the Midwest bringing precipitation to Ohio mostly in the form of rain. As this strengthening weather system encounters some of the aforementioned cold produced by the aforementioned "jet max" an area of snow will expand across the New York city area and in southern New England. North-central Vermont will be on the northern edge of this expanding area of snow which will begin in the early afternoon Friday and persist at a mostly light intensity into the night. By first tracks time on Saturday, we should have 3-6 inches of powder to ski in. Temperatures Saturday and throughout the weekend will be considerably colder verses some of the expectations earlier this week. High temperatures Saturday will struggle into the low teens, drop below zero Saturday night and then rise into the teens again Sunday. Winds will be out of the north most of the weekend but should not be very intense.

Storm #2
The second system will be stronger and a bit more dynamic. Its track will also be more conducive for a major snowfall for Mad River Glen and surrounding Vermont. Details are certain to change but the storm will follow a familiar story line of strong weather system in the Midwest transferring its energy to the Mid-Atlantic coast and depositing healthy amounts of moisture into New England. Along the coast, early snow will be followed by a transition to rain. Across the interior it will be snow which could turn heavy and lead to a widespread area of 1-2 foot storm totals. Snow will arrive later Sunday and continue into the night and will thus set up Monday as the best powder day of the year so far.

And could it be ?? A third ??
The possible third system will have impact within a day or so of Christmas Day. It will follow a period of very cold weather across interior New England in the wake of Monday's powder-fest. It will however be the third in this series of relatively moist systems to get shot out of the very unsettled pattern in the southern Rockies. It has the very wonderful look of 1993-1994 when the teleconnections were generally unfavorable, the storm track appeared precarious and yet the combination of a strong supply of cold combined with the split flow in the west yielded an epic season of powder. We can only hope that the results will continue to be as good as what this upcoming week appears to be. Enjoy it, I know I will !

2 comments:

Damon said...

Oh I hope you're right, I just rescheduled a day off and a meeting so I can ski Monday instead of Friday

Good news nevertheless!

John said...

exams are done friday morning...best news i could have gotten. Josh...thanks for this invaluable site, you are soldier in the service of powder...a prognosticator of powder. ok ill stop but thanks

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