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Summary: The southern edge of an unseasonably cold arctic air mass will slide out of Canada and over New England behind this afternoon’s arctic cold front passage (which will be accompanied by widespread snow squalls). However, its stay will be brief, from tonight through Friday night, before the axis of the cold trough in the jet stream wave pattern lifts out to our northeast. As a result, we will have a bit of a reprieve from the bitter cold spell we have been in on Saturday, as temperatures climb well into the 20s.
At the surface, high pressure will build in for Friday so we will see considerable sunshine. However, despite the high sun angle this time of year, with snow/ice cover to reflect most of the incoming sunlight back into space there will be little success in warming the frigid arctic air mass. As a result, temperatures will struggle to rise from below zero temperatures in the morning to near 10 during the afternoon. To add insult to injury, winds will be fairly brisk both tonight and Friday so wind chill temperatures will drop into the teens below zero overnight tonight and hover around zero during Friday afternoon.
The high pressure system will shift to our east on Saturday, so there will be more cloudiness, but “milder” air will move in via the southwesterly return flow around the high pressure system (clockwise flow around highs). A weak surface low pressure system moving by to our north will drag another, much weaker, cold front through Saturday night and into Sunday. This frontal passage will be accompanied by some snow showers and flurries, but nothing more than that.
It is at this point that the forecast gets tricky….the front will stall to our south and a surface low pressure system will develop in the lower Mississippi Valley Sunday night and move rapidly eastward along the front, moving off the Mid-Atlantic coast and out to sea well to the south and east of Cape Cod Monday afternoon and evening. The European Model (ECMWF) which has been the most consistent and accurate model with our many coastal storms this winter has been projecting the storm track close enough to the coast to give us a good dose of snow, on the order of 8-12″ during the day on Monday. The model has been very consistent with this solution since this past weekend. However, the most recent run projects a much stronger influence by cold high pressure over Canada, with the jet stream deflected more to the south, and the storm tracking out to sea well to our south. With this track we would only receive a few inches of snow at most.
The long range U.S. model (GFS) has been more inconsistent. In general, its’ solutions have projected the storm further south than the ECMWF but with a track that would still bring us 4-8″ accumulation. However, the latest run from this model has shifted the storm track further south as well, along a track that would bring us on the order of 3-6″.
So….here is what I think at this point. Despite the fact that March storms tend to carry quite a bit of moisture and precipitation, I think that the jet stream configuration looks way too zonally oriented (flat, west to east) over us on Monday to give us a big snowstorm. It looks like we will be at the northern edge of the precipitation shield and the storm will move by quickly. My best projection would be a light (2-4″) snowfall with southern regions receiving the most. However, I would not be surprised if this storm completely misses us. I plan to update this forecast late Saturday afternoon…..
Snow squalls ending early this evening, by around 7 or 8 pm. Likely accumulation 1/2″-1″ in most locations. It will then becoming mostly clear, windy and bitterly cold.
Low temperatures in the low to mid single digits below zero. Wind chill temperatures will be in the teens to 20s below zero.
West-northwesterly winds at 10-20 mph with gusts 30-35 mph.
Mostly sunny in the morning, partly cloudy in the afternoon. Breezy and very cold.
High temperatures near 10 in Pittsfield; near 10 to low teens in Lee, Stockbridge, Adams, North Adams and Williamstown; low teens in Great Barrington and Sheffield and; mid to upper single digits over the elevated terrain. Wind chill temperatures ranging from the teens below zero in the morning to near zero during the afternoon.
West-northwesterly winds at 10-15 mph during the morning, diminishing to 5-10 mph during the afternoon.
Mostly clear and very cold.
Low temperatures in the low single digits below zero.
Winds light and variable.
Mixed clouds and sun and milder.
High temperatures in the upper 20s in Pittsfield, Lee, Stockbridge, Adams, North Adams and Williamstown; near 30 in Great Barrington and Sheffield and; low to mid 20s over the elevated terrain.
South-southwesterly winds at 8-12 mph.