Sunday, December 13, 2015

December 2015 poised to completely bite the dust

Believe me I want to bring better news but I don't have any, not yet. We will get a burst of winter chill this upcoming weekend but it mostly comes in the form of sub-freezing temperatures. What's worse is that the chilly near average temperatures will be quickly displaced in the days prior to Christmas and this pretty much cements the month certainly as one of the worst December's I can remember and quite possibly one of the worst months of skiing in the east I can remember. December 2006 also featured an El Nino, albeit weaker, and that month along with the first half of January was also extremely mild. Given the behavior of the Jet Stream in the Pacific and wrong type of preferential treatment being provided by the Arctic Oscillation, I would be very happy if we could simply mimic the results that winter which featured an epic 6-week stretch of weather.

A healthy dose of warm rain Monday evening and Monday night will precede a few days where the weather is simply "not as mild".  I mean, it's a pretty ugly scene in Vermont when temperatures in any of the winter months fail to drop under the freezing mark in the wake of a cold front. Wednesday and Thursday will see temperatures near but not much under the freezing mark during the early morning before readings rise to near 40 during the afternoons. Another storm system then approaches Thursday evening but with essentially zero cold air support. The storm will actually transition much of its energy to the coast late Thursday which is typically a very encouraging development. In this case, temperatures may remain in the 30's but precipitation will be mostly rain with a few areas of freezing rain.

Flurries and snow showers finally arrive with the arrival of much colder weather later Friday. Conditions look pretty good for at least a few inches of Champlain/Terrain induced snow particularly Saturday and Saturday night.  A few flurries may linger into Sunday before we say adieus to the cold early next week.

The jet stream in the Pacific is simply behaving horrendously for us. The coupling of the troughing in the Bering Sea over the ridge in the central Pacific is just catastrophic. Some have argued to me that this El Nino does not have a causal relationship with this feature but this is incorrect in my opinion. The trough in the Bering Sea is unfortunate but the ridging in the central Pacific can certainly be attributed the massive area of warm water near the equator. My concern relates to this aforementioned AO and it's inability to attain any sustainable negative index. I have noticed this during many of the winters I have followed the weather. The AO has a preferential sign during certain seasons. The 2009-2010 much weaker El Nino featured the biggest negative AO ever recorded. This year we are setting up to be largely the opposite. Someone more academic than me is going to have to chime in as to why this tends to occur, or perhaps it's all in my head.

Anyway, the weather pattern out around Christmas is showing glaring signs of another massive thaw. The ensembles over the past 24-48 hours have really consolidated around this scenario and I don't want to sugarcoat it. The rest of the month looks pretty shot. 

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