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Summary: As I expected (hoped?) the computer models have begun to converge around the same general scenario for the coastal storm Tuesday night and Wednesday. The deep trough in the jet stream wave pattern responsible for generating the strong surface low pressure system along the East Coast will be centered to our west. As a result, the track of the surface low up along the eastern edge of the trough will cause the low to hug the coast and then draw the low center inland over New England, probably directly over, or close to, Berkshire County. This will allow warm air to be drawn in from the warm Gulf Stream and result in the vast majority of the precipitation associated with this low to be in the form of rain. The only place that significant snow accumulations are likely is over western and northern NY state and, possibly, the northernmost mountains of Vermont. However, even in northern VT the snow will likely change to rain.
The time frame of this event for Berkshire County presently looks like this: There will likely be a brief period of snow and mixed frozen precipitation as the precipitation begins late Tuesday afternoon or evening. There will then be a relatively rapid transition to rain early Tuesday evening. I do not expect any significant snow or ice accumulations during this period. Any snowfall should total less than one inch and the roads should not become snow covered or icy as temperatures will likely be at or just above freezing. Rain will then fall, heavy at times, Tuesday night and through Wednesday morning. The heaviest rain will fall during the early morning hours before and after dawn. Rainfall totals will likely be over one inch and may be significantly greater than that. Rain will then taper off during Wednesday afternoon. Temperatures will rise well above freezing Tuesday night and into the 40s late Tuesday night and into Wednesday. As the low pulls away Wednesday night, very cold air will be pulled in behind the departing low and temperatures will drop precipitously. As a result, any wet roads could become icy overnight. It is also possible that the precipitation could end as a brief period of snow Wednesday evening and there may be some “backlash” snow showers later Wednesday night into Thursday morning. There could be an inch or so of snow during this period, particularly over the elevated terrain. It will turn very windy and cold for Thanksgiving Day.
If you are traveling Tuesday and Wednesday there should not be any significant travel issues except for possible flooded roadways with snowfall isolated to western and northern NY state and far northern VT. If you are traveling in Berkshire County or north and/or west of Berkshire County Wednesday night there could be some slick roads with a thin coating of snow and some ice as the rain ends as a period of snow during the evening and roads become icy. The only place I would expect snow accumulations greater than an inch or two Wednesday night would be over northern New England. If you are traveling to the south and east of Berkshire County you should only encounter wet, but possibly, flooded roadways. There could be some slick spots to our south and east late Wednesday night as any wet roadways freeze.
Sunday Night
Mostly clear, breezy and very cold. Winds will begin to diminish after midnight.
Low temperatures in the upper single digits to near 10, with some mid single digits over the elevated terrain. Wind chills in the single digits below zero.
West-northwest winds at 10-20 mph in the evening, with some gusts to 30 mph, decreasing to 5-15 mph after midnight.
Monday
Mostly sunny to partly cloudy and still cold, but considerably milder and less windy than Sunday. There may be an increase in high clouds late.
High temperatures near 30 in Pittsfield, North Adams, Adams and Williamstown; low 30s in Lee, Stockbridge, Great Barrington and Sheffield and; mid to upper 20s over the elevated terrain and hilltowns, depending on elevation.
West-northwesterly winds at 5-15 mph in the morning, shifting to southwesterly at 5-10 mph during the afternoon.
Monday Night
Increasing clouds during the evening, becoming mostly cloudy after midnight. There is the chance of a snow shower toward morning. Probability of precipitation 40%. Any accumulations should be nothing more than a dusting. Not nearly as cold as previous nights.
Low temperatures generally in the low 20s.
Southwest winds at 5-15 mph.
Tuesday
Mostly cloudy. There is a good chance that light snow or mixed precipitation will develop late. Probability of precipitation 50%. Snowfall accumulations 1″ or less.
High temperatures in the mid 30s in Pittsfield, North Adams, Adams and Williamstown; mid to upper 30s in Lee and Stockbridge, Great Barrington and Sheffield and; low 30s over the elevated terrain and hilltowns.
Southwesterly winds at 5-10 mph, shifting to southeasterly late.
Tuesday Night
Any light snow or mixed precipitation will change rapidly to rain during the early evening. Rain, becoming heavy at times after midnight. Probability of precipitation near 100%. Most likely rainfall totals 1.00″ to 1.50″. It will become milder, with temperatures will rise through the 30s and into the 40s by morning.
Wednesday
Rain, heavy at times during the morning, particularly early, tapering off late morning and during the afternoon. Probability of precipitation near 100%. Likely rainfall, an additional 0.25-0.50″. The rain may end as a period of snow late in the afternoon or evening and an inch or so of snow could fall in some places. It will be in the 40s during the morning but temperatures will begin to fall rapidly during the afternoon.