A very big storm is coming to the area early this week, no question about it. Below I will detail timing and accumulations and will go somewhat into why this is happening so bear with me if things get a tad technical.
There’s going to be a lot of snow. Amounts across most of the area will be on the order of 1-2 feet with 2-3 feet possible across CT and extending NE from there. Details are on the map below.
Not only will lots of snow fall, but it will be blowing around in very high wind gusts. More details on that below. Snow will begin falling Monday night becoming heavy early Tuesday morning becoming very heavy during the day Tuesday. I expect every single school in New England will have a snow day Tuesday and many areas have a good shot at seeing another snow day Wednesday as the storm will stall out off the coast for most of the day Tuesday.
Here is the GFS vertical velocity map for 7 AM Tuesday. What you should take away from this very complex map is that red/purple = extremely heavy snow. Bands of snow falling at 1-3″ per hour will rotate through the region Tuesday morning and sticking around through the day Tuesday into Tuesday night.
Why will this storm stick around so long? A combination of complex upper air phenomena will allow for the storm to stall off the coast for about 12 hours on Tuesday swinging band after band of snow into the region.
The explanation for this comes from the fact that a storm offshore needs another storm, usually an upper air disturbance with little surface impacts to kick it out to sea. We have a vigorous disturbance that would, under normal circumstances, kick the storm right out to sea. However, the upper low is so powerful that it simply absorbs this storm and feeds on its energy. We then have to wait for the next disturbance to come and push the storm out to sea. This push comes on Wednesday morning.
All in all, very heavy snow bands will be stuck rotating into the region all day on Tuesday. Snow will be light and fluffy and thus the fluff factor will be high, contributing to higher totals. Widespread amounts of 1-2 feet are likely except for some areas west of Boston where totals could approach or exceed 2 feet. Lighter snows can be expected in the mountains where totals will hover right around a foot.
Even with impressive accumulations, snow will not be the only major headline. As the storm undergoes explosive strengthening offshore, the pressure gradient between very high pressure over Canada and very low pressure off the coast will intensify and the winds will follow suit. With such dry and fluffy snow, the winds will cause blowing and drifting snow thus reducing visibilities and causing blizzard conditions.
Here is a map of the expected winds for this storm. The highest winds will be during the day on Tuesday. The combination of very high winds and a lot of dry, fluffy snow will create very low visibilities and the prolonged duration of the storm will mean that the criteria for an official blizzard will have no problem being met along the coast and in adjacent inland areas.
Here are the official watches and warnings from the NWS in Gray, Maine showing a large area under blizzard warnings with the remainder of Maine and most of New Hampshire under Winter Storm Warnings.
I’ll have another full update tomorrow evening.