How sweet it was! Today’s 50-55 was a nice bonus but a major change in the weather is about to happen. The strong winds of 30-50 mph were heralding the arrival of a cold front early this afternoon and now, ladies and gentlemen, winter takes charge. There is no doubt about the arctic air rushing in but there remains much uncertainty regarding the amount of potential snow tomorrow night into Tuesday morning. There are two potential snow events this week and the second one on Friday is more forecastable at this time than the event on tap late tomorrow. As upper level energy transits from the Great Lakes to the Atlantic Ocean, a storm is destined to develop southeast of the region. Apparently, an inverted trough hanging northwestward from the storm center is primed to be the focus boundary for the heaviest snows. The precise placement of this convergent zone is crucial to accurately nailing the zone of heaviest snowfall. If that can be determined, the next unknown is the amount of potential snowfall in that axis of action. With the above average temperatures of the ocean and the extremely cold air coming in from the northwest, it would appear that the stage is set for a ribbon of prolific snowfall. With that said, conditions must be perfect for this to materialize and these specialized troughs rarely are forecastable in terms of precise placement and volume of snow. Nobody but nobody can accurately deliver a projected snowfall map with confidence tonight. We must wait until later tomorrow to decide if this so-called Norlun Trough will indeed materialize and if the sliver of heavy snow will be near the coast or all offshore. All I can say at this point is to project the most likely area for some heavy snow and that area is southwestern ME, southeastern NH and northeastern MA. Secondary areas of concern are the Plymouth County coastal plain and parts of Cape Cod.
There is no question about the cold air taking charge all this week. Lows by morning will be in the upper teens to lower 20s with highs tomorrow in the upper 20s to lower 30s. After morning sunshine, some snow showers will erupt later in the afternoon with the possible belt of heavier snow near the coast tomorrow night and Tuesday morning. The coldest air arrives after the system departs on Tuesday. Expect highs of 20-25 then with lows near or below zero near and north and west of Boston Wednesday morning. Highs Wednesday will be 10-15 at best then down to near or below zero Wednesday night recovering to 15-20 Thursday. The next storm will cross the Midwest midweek and arrive in the Northeast on Friday. Several inches of snow are probable from this system unless its track shifts. There could be a switch to some rain over southeastern MA and Cape Cod. It is too premature to be confident of specifics right now. After the storm exits Friday night, next weekend will be cold with subfreezing weather continuing.
I will return in the morning for Melissa Mack.