Summary: It looks like we may have seen the last of the sun until at least Monday. Welcome to March! The cold pool aloft (upper-level low) continues to spin over us as it has become separated (cut-off) from the jet stream to our south. This will keep us cloudy and relatively cold with scattered flurries and snow showers over the entire weekend. In addition, a disturbance within that cold pool will generate some divergence aloft that will result in considerable ascent above Berkshire County on Saturday afternoon and Saturday evening. As a result, probabilities are fairly high that we will see a period of snow/snow showers that may result in some minor accumulations. The greatest chance for accumulation is over the elevated terrain in central and, particularly, northern Berkshire where 1″-2″ is likely. In the lower elevations in central and northern Berkshire and the elevated terrain in South County, a coating to 1″ is likely with probably nothing more than a coating in the lower elevations of South County.
There will likely be some minor improvements to our weather on Monday and Tuesday and into Wednesday as the trough in the jet stream over the eastern half of the country flattens out a bit and tries to lift to the north. This will pull the cold pool aloft a little farther to our north and east. It will still be fairly cloudy and cool but we may see a little bit of sun and snow showers will be less likely.
Also on Monday and Tuesday, a strong disturbance in the jet stream will move across the Northern Rockies and then dive south into the base of the trough (same stubborn trough I have been talking about) over the eastern U.S.. This will serve to amplify the trough greatly, eventually causing it to become negatively tilted (east to west tilt) as it reaches the East Coast on Wednesday. This will generate a large amount of divergence in the upper-level (jet stream) winds causing marked ascent in the atmosphere and development and intensification of surface low pressure along the Carolina/Mid-Atlantic coast. It appears that this surface low will eventually weaken as it becomes separated from the jet stream and drifts slowly to the east off the coast. This is the scenario at least, with some significant differences between models, that the two main long-range mathematical models (GFS and ECMWF) depict. According to the GFS model, the low will become a bit deeper and will drift northward along the coast before it begins to weaken and drift east. This would result in a fairly significant wet snowstorm Wednesday night and Thursday for Berkshire County. According to the ECMWF model, the storm will stay south of us and we will receive no precipitation at all. The ECMWF model has been better in the long-range so the smart money would say that the storm will miss us. However, there are certain aspects to the GFS scenario that I find more realistic. Also, throughout this entire winter, the projected tracks of these storms 5-7 days out have drifted north as the day of the storm approaches. I am already seeing this in the last few days. So…..I would tend to think we are going to get some wet snow here sometime Wednesday (probably late) into Thursday. I will be away this weekend but I think the picture should be much clearer when I post a forecast on Monday. In any case, the warm-up I discussed yesterday for late next week may be a bit harder to produce with this storm moving near to us. However, the long-term trend into the following week looks much milder for us as the jet stream pattern becomes more zonally (west to east) oriented and drifts a bit to the north.
Friday Night
Mostly cloudy to overcast with a chance of a snow shower or flurry. Probability of precipitation 30%. Nothing more than a dusting in a few locations, mostly over the elevated terrain.
Low temperatures generally in the upper 20s, mid 20s over the elevated terrain.
Northwest winds at 5-10 mph.
Saturday
Overcast with a chance of a snow shower or flurry in the morning. A period of mostly light snow or snow showers will likely develop mid to late afternoon and continue into the evening. Probability of precipitation 70%.
It will remain on the cool side with high temperatures in the mid 30s in Pittsfield, mid to upper 30s in Adams, North Adams and Williamstown, upper 30s in Great Barrington and Sheffield, and low 30s over the elevated terrain and hilltowns.
Northwest winds at 10-15 mph.
Saturday Night
Overcast. Light snow or snow showers are likely during the evening. There is just a chance of a flurry or snow shower after midnight. Probability of precipitation during the evening 70%, dropping to 30% after midnight. Total snow accumulation from any afternoon and evening snow is: nothing more than a coating in the lower elevations of South County, a coating to 1″ in the elevated terrain in South County and the lower elevations of central and northern Berkshire, and 1″-2″ over the elevated terrain in central and northern Berkshire.
A little colder than Friday night with ow temperatures in the mid to upper 20s in most locations, low to mid 20s over the elevated terrain.
Northwest wind at 5-10 mph.
Sunday
Overcast and continued fairly cold. Still a chance of a snow shower or flurry, predominantly in central and northern areas during the afternoon. Probability of precipitation 30%. Nothing more than a coating in a few spots.
High temperatures in the low to mid 30s in Pittsfield, mid 30s in Adams, North Adams, and Williamstown, mid to upper 30s in Great Barrington and Sheffield, upper 20s to low 30s over the elevated terrain (depending on elevation).
Winds will continue a bit breezy, out of the northwest at 10-15 mph.