By James M. Arnold, Weather Specialist
Region – All the pieces for the storm of Sunday night into Tuesday are coming together and promise to bring yet another heavy snowfall to central Massachusetts. The outlook for Saturday and Sunday remains pretty much the same as it did yesterday. Light snow will overspread our area by late Saturday morning or around noon and will continue off and on for the rest of the day and into the evening hours. Accumulations should only be an inch or two by Saturday evening. Very light snow will likely continue off and on throughout the night and continue into Sunday when it will become a bit steadier and heavier during the day and into Sunday evening. Another 2 to 4 inches of accumulation will fall during Sunday. All this from a couple of weak disturbances and some overrunning caused by a persistent easterly flow off the warmer Atlantic ocean.
During Sunday night a larger, better organized and slowly intensifying storm will be approaching us from the Virginia Capes and will bring with it a significant snow shield. If it’s Monday, can we expect anything other than a big snowstorm? This system will track just inside (to the west of) the benchmark, which is a very favorable track for our larger snow accumulations. Snow will become moderate to occasionally heavy around midnight Sunday night and will continue throughout Monday and well into Monday night as this storm will be a slow mover. While it does not have an abundance of moisture to work with, it has enough, in combination with very cold temperatures, to bring another 8 to 12 inches of snow to central Massachusetts. My best estimate for total snowfall for the entire time in central Massachusetts is 12 to 16 inches with isolated areas of up to 20 inches.
Wind should not be a serious issue but there will be enough for some blowing and drifting to occur. Along the coast there is a chance that the changeover to a wintry mix and/or rain line could reach the Cape and Islands and possibly parts of the south shore. This would hold down accumulations in those areas, but the cold air should hold in most inland areas. In the greater Shrewsbury area, temperatures will be in the 20s throughout the storm, likely falling into the teens Monday afternoon as colder air sweeps in behind the departing storm. Tuesday and Tuesday night will feature clearing and blustery weather and Wednesday should be a nice mid winter day.
Although Thursday will dawn clear and cold, all eyes will turn toward an approaching arctic front. Behind it will be some severely cold air, with record challenging temperatures. This is the airmass I have sent some computer graphics out illustrating guidance for our area, and although I think that guidance is overdone, it does demonstrate the nature of the airmass approaching New England. It likely will be colder than anything we have seen for some time. There may be a bit of snow during the frontal passage which will be followed by plummeting temperatures and increasing northwest winds. I’ll have more on the coming cold blast a bit later, but for now the snowstorm will take precedence.
Although you may get tired of hearing this, this much more snow will make snow banks all the higher and will make extreme caution and patience necessary while driving. Also, it will increase roof loads, further stressing flat roofs in particular.
James M. Arnold is a Weather Specialist working with Shrewsbury Emergency Management Agency; town of Princeton; Worcester Emergency Communications and Emergency Management Agency; Southborough Emergency Management Agency; town of Grafton and Wachusett Mountain Ski Area
