In spite of the expected disappointment regarding the outcome with our once promising storm this week, the mountain will be in the firm grasp of winter for at least the next 10 days and I am beginning to think most of the duration of February. The term "Polar Vortex" hasn't gotten too much mention on the blog so far this year. New England has been one of the mildest places in the U.S. relative to average through the first half of this winter and now beyond. This trend will get shattered during the holiday weekend as a very impressive looking PV will take dead aim at Vermont, dropping straight into interior New England early Saturday and bringing with it by far the coldest air of the season.
Big southern streamer is keeping forecasters in Boston busy yet again. Like all the other storms this season, this one will track far enough off the coast Monday to keep Vermont out of the significant snow but close enough to keep southeast New England in play for both accumulating snow and in this case wind. Blizzard warnings have actually been issued for the Cape for all those reasons. Snow will actually expand into Vermont for a time Monday evening into early Tuesday thanks to a general area of deformation but models are confining snowfall amounts to the 2-5 inch range for most of the state including the high country. The rest of Tuesday into early Wednesday should be free of precipitation since most of the snow will be confined to areas well south of New England. The better dynamics with this big upcoming polar branch disturbance will be further south and Vermont again misses the best snow as a result. We will ultimately see some additional snow later Wednesday into early Thursday as the atmosphere finally destabilizes enough to allow for a period of terrain enhanced snows. With some luck (vocabulary that is totally foreign to Vermont this winter) we could see some decent accumulations in the high country by later Thursday (3-6 inches) but I am hesitant to get too optimistic.
We get a preliminary taste of the chill late this week with temperatures cooling to the teens Thursday and single numbers Friday. The PV attack will be marked by a weak clipper system that should bring a small accumulation of snow late Friday. Most of what it will bring is bone chilling cold weather. Saturday's temps will struggle to eclipse the zero degree mark (-18 C). Sunday's temps may reach 10 thanks to some February sunshine but only after readings of near 20 below during the morning.
The cold will continue to moderate throughout the holiday week and there are glaring indications of another potential storm sometime in the February 16th-17th time frame. This should be another El Nino product that will arrive as the pattern and jet relax. Lots of questions regarding track and timing. My optimistic nature and fair assessment of the weather map tells me that enough cold air will remain present to keep precipitation frozen but I take nothing for granted this winter.
The pattern appears a little adverse thanks to a jet tightening in the Pacific and a weakened ridge in western North America between the 19th and 21st of the month but this appears very short lived. The MJO which we discussed in the last update should encourage a weakening in the strength of the jet in the Pacific. This should help to keep New England on the wintry side during most of the rest of February and provide another window for decent snowfall.