For The Rest Of Today Through Tonight: An area of high pressure will control our weather throughout the rest of today and tonight.
Skies throughout the rest of today will be sunny to partly sunny. High temperatures this afternoon will be between 35 and 40 Degrees. Northwest winds will gust up to 20 mph at times.
A clear night is expected tonight with low temperatures between 10 and 15 Degrees. This cold air will set the stage for the winter storm arriving Sunday afternoon.
A Long Duration Significant Winter Storm Will Affect Western & Central Mass From Sunday Afternoon Through Sunday Night, Monday, Monday Night & Tuesday Morning: A significant and long duration winter storm is still expected to affect Western and Central Mass starting Sunday afternoon and continuing through all of Sunday night, all of Monday and all of Monday night. The storm looks to come to an end sometime on Tuesday morning.
An area of low pressure is expected to form off of the New Jersey coast on Sunday evening and then stall near Nantucket during Monday afternoon and Monday night. From there, this low pressure system will head for Nova Scotia on Tuesday. The track of this storm is close enough so that not everybody across Western and Central Mass will see a pure snow event. Milder air will make it far enough north to leave precipitation as all snow in the Berkshires, the upper Pioneer Valley of Western Mass and across northern Worcester County. Across the lower Pioneer Valley, along the Mass Pike and across southern Worcester County, a messy mixture of snow to start with, followed by snow, sleet and freezing rain and then ending as snow can be expected.
This is not a typical quick hitting winter storm, but instead this will be a long duration winter storm that lasts almost 48 hours in some places.
Here Is A Timeline Of What I Am Expecting:
Sunday Afternoon Into Sunday Evening: Snow will overspread Western and Central Mass between about 1 and 3 pm Sunday afternoon. It looks like the snow will become moderate to heavy at times from late Sunday afternoon into Sunday evening with over 1 inch per hour snowfall rates at times. A solid 3 to 6 inches or so of snow accumulation can be expected with this initial round of snow.
Overnight Hours Of Sunday Night Through Monday Morning: Milder air will work its way northward causing the snow to change to sleet from the lower Pioneer Valley of Western Mass to southern Worcester County. Some freezing rain and freezing drizzle is expected as far north as northern and northeastern Connecticut. Further west and further north, all snow is expected to continue across the Berkshires, the upper Pioneer Valley of Western Mass and northern Worcester County, although the snow will be light in intensity.
The messy mixture of light snow, light sleet and light freezing rain is expected to continue through Monday morning across Western and Central Mass.
Snow and ice accumulations will be light with at most 1 to 3 more inches of snow accumulation. Around one tenth of an inch of ice accumulation is expected across northern and northeastern Connecticut.
Monday Afternoon: Precipitation will gradually change over to all snow, however, it will be very light in intensity. In fact, it is possible that the snow may end for a little while during Monday afternoon, but, beware that more snow is expected on Monday night and Tuesday morning.
Monday Night & Tuesday Morning: It looks like we will see another round of heavier snow beginning around midnight Monday night and continuing into the first part of Tuesday morning. Snowfall rates of 1 inch per hour is possible at times late Monday night and early Tuesday morning. An additional 3 to 6 inches of snow accumulation can be expected with this round of snow late Monday night and early Tuesday morning.
The snow will come to an end later Tuesday morning across Western Mass and during early Tuesday afternoon across Central Mass. This will be a long duration significant winter storm that lasts up to 48 hours in some spots. In addition, it looks like there will be 2 time windows where travel could be very hazardous – the first from Sunday afternoon to Monday morning when heavy snow will initially lead to very poor road conditions, which will be followed by an icy mixture of precipitation. The second time window will be from about midnight Monday night into Tuesday morning when our second round of heavier snow will lead to poor travel conditions. Travel Monday afternoon and Monday evening may be okay in many places as precipitation rates will be very light & it may actually stop for a while.
With that said, widespread activity and school cancellations are still expected from Sunday afternoon to Tuesday morning.
For those who have travel plans Sunday afternoon, Sunday night, Monday, Monday night or Tuesday morning - I would leave today or at the very latest first thing Sunday morning instead. Another alternative, if you can, is to delay your trip until late in the day Tuesday.
You will find my latest forecast total snow & ice accumulation map below.
Keep checking back for updates on this upcoming significant, long duration winter storm.