It's been a good 18 hours for snow lovers in the Berkshires. Things are looking up.
According to the models, the storm track is going to take a nice little jiggity-jog toward the west, and we are now more likely to see moderate and even heavy snow fall throughout Saturday. The National Weather Service in Albany has issued a Winter Storm Watch for area, and there's even some talk in the shadowy recesses of a weather chat room of a future upgrade to a Winter Storm Warning.
To understand why you might be seeing a great deal of spread (2" to 14") in the predictions for Berkshire County, you need to consider two very important factors that will dictate our snow totals.
1) Many of the models use a snow to liquid ratio of 10 inches for every 1 inch of liquid (10:1). But because the air is going to so cold--mid-teens for highs on Saturday--snow to liquid ratios could approach 20:1 ratios. Many maps we're looking at are showing 4-8 inches for Berkshire County (north to south), but they are using a 10:1 ratio. So, don't be surprised if we hit double digits everywhere in the county as long as the storm follows its predicted track.
2) There is going to be steep and drastic cut off line with this storm. It's conceivable Berkshire County could see 3-5" and neighboring Franklin, Hampshire, and Hampden Counties could see 12-18". The reasons for this are the aforementioned cold air and the formation of intense snow bands. Somewhere in central or western mass, the western edge of the storm will bump up against the bitterly cold air, and there the twain shall meet. Right at that meeting point--that's where the snow is going to pile up. Let's hope that intersection is directly over US route 7.
(Here's a very good image of snow band setting up vertically over central MA. We would want to see this set-up shift 100 mile to the west if we want 12-15" of snow.)
As for timing, tonight will be completely dry. Snow should start as early as daybreak in South County and gradually edge north. The snow should end around midnight Saturday. The duration is fairly short.
