By James Arnold, Weather Specialist
It is looking increasingly likely that our area will be impacted by a disruptive snowstorm later Thursday into Thursday night. A weak disturbance will be approaching from the Great Lakes region Wednesday night and Thursday and a secondary coastal storm will form around the Delmarva peninsula later Wednesday into Wednesday night. This will become the dominant system as it undergoes rapid intensification and its snow shield will overspread southern New England Thursday morning, likely reaching the central Massachusetts area around noon. There are however, a number of significant moving parts to this forecast.
1). Track. The coastal storm will stay close to the coast, crossing the outer Cape or between Chatham and Nantucket Island. This trajectory will allow for the associated strong northeast wind to bring the warmer marine air inland.
2). Temperature profile. This early in the season the ocean water temperature is still pretty high, which would result in the marine air being pretty warm, with the potential for moving the rain/snow line further inland. Just a few miles could make the difference between a little and a lot of snow.
The bottom line is that there will be a strengthening system to our southeast bringing snow to our area and all of Massachusetts initially. Over the coastal plain, the Cape and Islands, there should be a fairly quick change to rain after an inch or two of snow has fallen. Most of that snow will melt as temperatures rise. Further inland, snow will fall a bit longer and accumulate to 3 to 4 inches from east to as far west as the Route 495 corridor and as far north as the Mass Pike. North of the Mass Pike and west of Route 495 (further away from the marine influence) snow depths will pick up, with 4 to 6 inches likely nearer to Route 495 where a little rain could mix in from time to time, keeping accumulations down a bit in those areas, and reaching 6 to 10 inches in the greater Shrewsbury area. Further to the north and west in the higher ground communities there will be isolated local pockets of up to 12 inches. A general 8 to 12 inches is likely for the Route 2 corridor and northward.
As far as timing, it looks like snow will begin in our area around noon as mentioned earlier. It will become steadier and heavier throughout the afternoon and continue well into Thursday night, likely ending around midnight as flurries. Friday will see clearing skies after the snow ends with seasonably cold temperatures in the 30s.
Late New Year’s Eve we will be threatened by another disturbance potentially bringing some snow which could last into Sunday. This does not look like a significant storm at this time, but should be watched.
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