Tuesday, January 17, 2012

Snow from two different systems should turn this weekend into a winner

It still looks we have two potential snow producers on the weather map both of which should help turn the upcoming weekend into our 2nd consecutive winner. Both are products of a furious Pacific Jet Stream which is expected to grow even stronger over the next week. The first, as mentioned in the previous update carries little moisture but has plenty of cold to work with. It will spread clouds to the region Thursday afternoon and light but very fluffy snow Thursday night (the cold weather and lack of Atlantic moisture will help keep the density of this snow very light). Friday will therefore be a chilly powder day with 2-4 of new snow at first tracks time. Following a very chilly Saturday night with well below zero temperatures, milder air will begin its big push north. Cold air across interior New England, rarely gives up without a fight and the weekend should be no exception. Yes, the cold weather will gradually give ground but battleground will consist of an overrunning surface capable of producing a healthy period of light to moderate snow over the weekend, likely Saturday. There is a weather system responsible for all this and it will track from the central Rockies to the Atlantic coast very quickly Friday and Saturday. Where the moist conveyor sets up with this system remains a question so the range of possibilities for Saturday spans from a dusting to as much as 8 inches, but I expect something in the middle.

And then the pain begins. We will survive Sunday with below freezing temperatures and perhaps some lingering snow. I know the Pats and Giants are both playing huge games Sunday but winter might be taking an extended break after Sunday so it might be worth grabbing a piece if you can (For me the Giants will be tough to miss). It has been the Euro and its ensemble package which has been driving the train of a end-of-the-month January thaw. It all stems from the strong coupling of a trough across the Pacific Northwest and Canadian Rockies and a ridge across the desert Southwest. The result will be the formation of a very, very large ridge across centered over much of eastern Canada. How warm will it get and for how long ? I would expect a 3 day stretch of 40-plus maximum temperatures and 1 day with 50-plus temperatures. And I would also expect a rain event either in the middle or end of the week. Recent runs of the American GFS model do offer us an out next week by pushing the ridge far enough to the northeast so the warming is substantially mitigated. The history of this winter so far and the superiority of the European model in the last few months makes my educated guess an easy one to make but time will tell. Hopefully I get proven very wrong !

Things look a bit more encouraging toward the 1st of February when both the European and GFS Ensemble packages allow the ridging in eastern Canada to evolve into what could become a Greenland Block. This would turn the NAO negative and give us an ally in the fight against what has been a fierce Jet in the Pacific.

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