By James M. Arnold, Weather Specialist
After the little snow tease of last night that was less than advertised, the latest charts are signaling that a strong winter storm will be working up the coast bringing central Massachusetts a major dose of wintry precipitation, some strong winds especially near the coast and slightly milder temperatures.?? As usual, there are still a number of unanswered questions with this storm, and chief among them is the track.? Although cold air will be banked up to our north, it is not as cold as in our recent storms and warmer air will have an easier time moving inland than in the recent past.? As a consequence, missing the exact track by as little as 50 miles would have widespread precipitation type impacts.
Our storm is just now taking shape in the western Gulf of Mexico, (and is the first true Gulf storm of the winter) and by tomorrow, Atlanta, Charleston and points north will be dealing with another potential winter weather disaster for them.? By late tomorrow the storm will track off the Carolina coast and begin to move up the coast to the northeast.? It is the track from its position over or just to the east of the Virginia Capes that is crucial for us.? There are three track options from this location.? One is out to sea to our south, missing all but the south coastal areas of New England and leaving just a dusting of snow in those areas, with very little wind.? There is about a 10 percent chance of this happening.? A second option is for the storm to track right along or just over the coast which would mean we would see some snow in the beginning, followed a change to sleet, freezing rain and finally rain.? Wind would be more of an issue in this scenario due to our closer proximity to the center of low pressure, and should enough heavy wet snow accumulate on trees and wires, we could see some scattered power outages.? There is about a 25 percent chance of this option occurring.? The third option is for the storm to track just offshore passing over or just to the east of Nantucket Island.? This would bring a snow to rain scenario to the coastal plain from about Boston south, through the Cape and Islands.? This track too would bring a period of strong winds with the risk of scattered power outages.? There is about a 65 percent chance of this track verifying.
At this time it looks like snow will overspread central Massachusetts during the pre-dawn hours of Thursday morning, and become moderate to heavy within a few hours and continue throughout the day.? Assuming that my track assessment is correct, we will see a wetter and heavier snow that clings to everything it contacts.? Snow will wind down Thursday night followed by slow clearing and continued cold weather.? Since this storm is of Gulf of Mexico origin, it will have a rich moisture supply and could bring as much as 1.5 inches of melted precipitation to us, likely mostly snow, but with some variations across the area.? From the Boston area south and east through the Cape and Islands there will be a period of snow at the onset followed by a change to a wintry mix then all rain.? Inland through the Route 128 corridor to the Route 495 corridor there will be more snow and less chance of rain as one moves to the west, with Route 495 being about the western extent of any meaningful mixing with rain.? Areas south of the Mass Pike will also see the risk of rain mixing in at times, but that area will still see more snow than rain.? Once again, it is the area north of the Mass Pike and west of Route 495 that runs the risk of seeing the most snow, with the jackpot area being the higher ground communities to our north and west.? Temperatures will be milder than in previous storms, holding in the high 20s to low 30s in central Massachusetts to the high 30s to around 40 in coastal areas.? All areas will see some wind during this storm, the strongest along the coast but still some wind in inland areas and the possibility for scattered power outages does exist throughout the area.? Coastal flooding should not be an issue, as winds will be weaker than in some of our storms this winter, but erosion of east facing beaches could occur.
An update will be prepared tomorrow afternoon and I should have a better understanding of the details for this storm event.
?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