With two successive runs of the European Model advertising the development of an east coast low pressure center over southern New England Sunday the 8th. The last run of the Euro showed the storm "bombing" near Boston Harbor and yielding foot-plus snows for much of the Green Mountain spine. The American model is not on board with the Sunday-Monday event but the Canadian model does show some indications of a storm albeit a smaller storm. The differences in the model are easy to decipher. The European simply shows a more potent upper level impulse capable of assuming the "protagonist" role. The American model no protagonist but merely a cold front innocently doing away with the mild weather we are expecting this Saturday.
A potentially stronger weather event or precipitation producer is more than possible for late in the week. This is, as promised, the beginning of a much more active and much more interesting period in our winter weather. This weather system will likely approach New England as much of the cold weather has made its exit. It also may travel along a path that could spread rain, at least initially to much of Vermont although this remains somewhat uncertain. There is a strong and very fresh supply of cold that may ultimately get enveloped into this storm and allow for a significant period of snow before temperatures return to typical January levels for the middle of the month.
The best news however involves the long long long awaited Arctic Oscillation sign switch. Yes, this is the decisive turn that has eluded us. This turn in the AO will put the breeze at our backs by the middle of the month and although we will still need to contend with a negative PNA with much of the jet energy in the west, the AO is the big enchilada and by January 12th or 13th it will be on our side of the pitch.