Monday, December 7, 2015

The gory details of bad to worse this weekend

It isn't a pretty sight for any of the ski areas across the east and it ain't getting better any time soon I am afraid. Over the last few days, models have more or less decided that the trough across the west will consolidate around two massive systems this weekend. Both will pummel the west with snow and deliver many ski areas there, particularly around Lake Tahoe, some of the best skiing in a few years. The last two cold winters at MRG have not been kind to the west lets not forget. This consolidation of the trough in teh west forces the situation from bad to worse across the east. The massive upper ridge which has locked itself in across eastern North America will get another boost allowing for big time and widespread warmth almost everywhere in the northeast. Models have backed off a touch on the magnitude of the warm weather, so maybe it won't quite reach 70 in parts of Vermont. Needless to say we are looking at an extended thaw, though the only thawing is the few inches of crust at the summits.

First chance for precipitation comes Thursday after what has been a rather nice stretch of dry weather. Precipitation on that day will be rain with a few isolated pockets of freezing rain. Friday through Monday are all very warm. How warm depends on the ability of the lower troposphere to mix itself out which will require some healthy southerly winds. Models are still a little unsure regarding how much of this very warm flow will reach central and northern Vermont. If we can achieve some sunshine, temps will be off to the races, reaching as high as 60 even at the base of MRG. If winds remain calm, low clouds, fog and drizzle will keep readings in the 40's and 50's. A moist weather system will track toward Quebec early next week. This is the first of the two big western storms, and this will bring more rain on what will at that point be a very bare ground.

The 2nd of the two big systems in the west will have some colder weather to work with but not much. In addition, the track of this system is not looking favorable. Still, there is some chance for at least some snow along with mixed precipitation and rain during the middle to later part of next week 16th-18th.

The two big critical variables remain extremely problematic right now. No high latitude blocking indicated by the positive AO and the tightened jet in the Pacific indicated by the positive EPO. Some have pointed out to me that the various ensemble forecasts are showing a negative AO in two weeks around the time of the solstice. The jet stream anomalies tell a different story however and are showing no blocking of any kind through nearly the Christmas holiday. I would thus conclude that yes we could get a brief surge of cold for a day or two but the pattern is not supportive of any type of persistent cold through the Christmas Holiday. I am still holding out hope for a juicy southern streamer to deliver a good elevation sensitive interior snow. There is a slight, slight chance for this with the storm later next week and a better chance during the week leading up to Christmas, but this is clearly the best we can do right now.

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