After a fresh topping of an inch or so of more powdery snow last night in some locations, once clearing took place, it was a picture perfect day provided by the contrast of the deep blue sky and the snow-covered trees and landscape north and west of Boston. Temperatures topped out in the range of 32-37 and those numbers will be matched and perhaps exceeded by a few degrees tomorrow. Enjoy it while it lasts because once it strikes the freezing point early tomorrow evening, it will remain subfreezing for about 112 hours which brings us to midday Saturday! After tomorrow’s near 40 degrees, without a doubt, this is going to be one frigid week. As cold as it is projected to be, it could actually be worse because some super wicked cold air will be advancing from around the polar region southeastward across central and eastern Canada. The core of this brutally cold air whirls around in Ontario and Quebec and we only receive the fringe effects but that is nasty enough. Northern ME will be numbed in subzero nighttime air as cold as -20 to -40 later this week! Brrrrrrr! Daytime highs in eastern MA will run from near 20 on Tuesday to the middle to upper teens Wednesday and Thursday then back to 20 on Friday. Overnight lows will run in the single numbers above zero to some single numbers below zero farther north and west of Boston.
The harsh cold is a given but snowfall is uncertain. As explained yesterday, there are numerous perturbations in the jet stream which translate into several clipper systems charging southeastward from central Canada to the Great Lakes to the Mid-Atlantic region. Without any significant downstream blocking backing up across Greenland into northeastern Canada, the flow is very progressive resulting in the usual fast pace of the clippers. As they scoot along, there is only a small window of opportunity to release a spell of snow. Usually the clippers are starved for moisture but upon passing over the western Atlantic, they feed on the ocean and begin to blossom with heavier precipitation spreading out. The northwestern flank of these clippers can crank across especially southeastern New England with a dumping of a few inches of snow. With the arctic air pouring in at the time of passage this Tuesday afternoon and night, the potential exists for some fluffy snow to accumulate over Cape Cod and perhaps extending northwestward toward the Boston area. Over the last several days, the models have been indicating that a second clipper would threaten the same area Thursday afternoon and evening. With each model run, there has been slightly differing solutions meaning on again/off again. The most reasonable forecast at this time would be for a few to perhaps several inches on outer Cape Cod ranging down to a few inches to a dusting closer to Boston and little or nothing farther north and west of the city from Tuesday’s potential. Once again, it looks like the mountains will miss out on the action again. Currently, Thursday’s threat has decreased. We must remain vigilant to some revision going forward but I am not expecting to ramp up any of these clippers to major storms for our area. After a breather next Saturday with temperatures finally rising slightly above freezing, another arctic outbreak will occur next Sunday. Unfortunately, the heating demand is definitely going to skyrocket again.
Todd Gutner will post his thoughts in the morning and Eric Fisher will follow later in the day.
Enjoy the rest of the holiday weekend.