The following forecast is provided by Cindy Bird as part of lab work for the Introduction to Meteorology course (ATM-145) under my supervision. The forecast discussion is mine……
The slow moving coastal low pressure system which brought us several days of overcast, cool temperatures and rain is weakening and finally pulling away through the Canadian Maritime region. As a result, skies will begin to clear this evening. Surface high pressure will build in briefly for the day on Saturday so we will finally have a nice day weather-wise with a good amount of sunshine and mild temperatures approaching 60 degrees.
As mentioned in the previous discussion, a vigorous mid/upper level disturbance, presently over south-central Canada, will “dig out” a broad trough in the jet stream wave pattern as it rotates through the base of the trough over the next 24-36 hours. As the disturbance dives southeastward across the Great Lakes, it will generate a surface low pressure system north of the Great Lakes tonight and Saturday that will move southeastward across northern New England on Saturday night and Sunday. The cold front trailing this surface low (and signifying the leading edge of much cooler air within the previously mentioned trough) will move through during the evening Saturday with a few scattered rain showers. During the day on Sunday, with cold air (within the trough) in place over Berkshire County, a strong pressure gradient will set up between the strengthening surface low departing to our northeast and strong high pressure to our southwest. This will result in brisk west-northwest winds across our region. As a result, we likely will see the first “lake-effect” event of the season. Moisture from the Great Lakes picked up by these winds will result in downwind showers, enhanced by the elevated terrain. For Berkshire County this means that Sunday should be a mostly cloudy, breezy and very cool day (temps generally in the 40s), with occasional showers, particularly morning into early afternoon. Even though temperatures aloft will be cold enough to support snow, this early in the year, boundary layer temperatures are too warm to support snow in the lower elevations. However, the higher terrain could actually see some snow flurries/showers although no accumulation is expected.
As this low pulls away, surface high pressure will build in from the west for Monday and Tuesday with a good amount of sunshine and milder temperatures.
Friday Night
Clearing skies this evening, becoming partly cloudy and seasonably cool overnight.
Low temperatures in the upper 30s, mid 30s over the elevated terrain.
Northwesterly winds at 5-10 mph this evening, becoming light westerly after midnight.
Saturday
Mostly sunny to partly cloudy and mild. Clouds will increase late in the day.
High temperatures near 60 in Pittsfield, Lee, Stockbridge, Adams, North Adams, and Williamstown; near 60 to low 60s in Great Barrington and Sheffield and; mid to upper 50s over the elevated terrain.
Westerly winds at 5-10 mph, shifting to southwesterly in the afternoon.
Saturday Night
Variable cloudiness with scattered showers likely. Showers are most likely during the evening, with the frontal passage, and again toward morning (lake effect). Toward morning the showers could be snow showers or flurries over the elevated terrain. Probability of precipitation 60%. Probabilities are greatest over the elevated terrain in western sections (Taconics). Likely rainfall totals 0.10″ or less. No snow accumulation is expected. It will become breezy toward morning.
Low temperatures near 40, upper 30s over the elevated terrain.
Southwesterly winds at 5-10 mph, shifting to west-northwesterly after midnight and increasing to 10-15 mph toward morning.
Sunday
Mostly cloudy, breezy and cool. Showers are likely, mostly light, particularly during the morning into early afternoon. Snow flurries or snow showers are possible during the morning over the elevated terrain. Probability of precipitation 60%. Greatest probabilities over the elevated terrain to the west (Taconics). Likely rainfall totals 0.10″ or less. No snow accumulation expected.
High temperatures in the mid to upper 40s in Pittsfield, Lee, Stockbridge, Adams, North Adams and Williamstown; upper 40s in Great Barrington and Sheffield and; low 40s over the elevated terrain.
West-northwesterly winds at 10-20 mph (strongest winds at higher elevations) with occasional gusts to 25-30 mph.
Sunday Night and Monday
Mostly cloudy overnight with still the slight chance of a sprinkle or light shower. Partly cloudy and milder on Monday. Lows in the mid 30s and highs in the mid 50s.