In just about 24 hours from now things will start to look a lot different with a quick-hitting, but powerful Nor’easter setting its eyes on New England. Even though it’s moving quick, it’ll drop a foot of snow in spots. So doing the math, it’s going to have to snow hard for a while to get to those numbers. The heavy snow and travel disruption will be our biggest impacts, but coastal wind and coastal flooding will be largely impactful as well.
Let’s start with the snow, that’s what everyone’s talking about. There’s a large area of 9-12″ that will account for much of the area. The northern side of the storm will feature a sharp drop off in snow totals where we could go from close to a foot down to a half a foot in the span of a few towns. Additionally, the northeast wind that eventually turns northerly will cut down numbers on the coast — that’s not to say you won’t have to shovel and move snow.
Boston also has a complicated forecast. The initial northeast wind will cut back on accumulation on the coast while it accumulates from the get-go just away from the water. As the wind turns to the north, even the coastal neighborhoods of Boston will see the heavy snow. So while Logan, Eastie, Southie, and Dorchester pick up 8-9″ of snow, neighborhoods like JP and West Roxbury could see 10-11″ of snow.
So the snow accumulation is substantial and the storm is here from a roughly 12 hour window from 5am-5pm. The snow will initially come in light and for our southern spots may even start as light rain. At the end of the storm it will slowly taper off. So if you chop off about 2 hours on either side from that window mentioned above, that means during the heart of the storm, snowfall rates will be 1-2″ per hour to get to these tallies.
Here’s future radar showing just that. At 5am, light snow starts to break out and for southeast Mass even some light rain. It will stay that way for just a couple of hours as the snow fills in fast. At this point, early tomorrow morning, travel isn’t too bad and roads are just wet.
Already by 8am the snow fills in and becomes heavier. The storm is intensifying rapidly and by doing so, pulls in cold air from the upper levels of the atmosphere. So by 7am the snow has filled in for everyone, even across the Cape and Islands. Also notice the deeper blues starting to develop — those are the bands where snowfall rates could exceed 1″ per hour.
And once we get into the heavy snow, it will snow… hard… for several hours. One thing to point out is notice the general trend of the lighter blues across southern New Hampshire and far northern Massachusetts. That’s the sharp cutoff in snow totals I was talking about earlier. While it will snow, it just won’t be quite as hard as some of the southern cities.
The snow continues into the early afternoon, keeping travel difficult all day long. It really is a good day to hunker down at home and take advantage of any work from home opportunities you might have. Notice by 1pm we’re starting to see the snow taper off across western Massachusetts while it continues to thump pretty good across eastern Massachusetts.
By 4pm, we’re all pretty much free from the snow aside from the Cape where it should wrap up around 5pm.
While the wind will be strong, I think our second biggest issue is going to be coastal flooding and beach erosion. Tides are astronomically high with this storm so it won’t take much wave activity for some coastal issues.
There’s a coastal flood warning in effect for Boston and south for 1-2 feet of inundation. North of Boston is a coastal flood watch — and that means just that, we’re going to watch one more model run, one more set of data, before deciding if those areas will also be included in the coastal flood warning. The highest tides are Tuesday afternoon and overnight into Wednesday morning. At this point the wind is becoming more northerly rather than northeasterly. So the timing of the wind with the highest tides favors more issues on beaches that are exposed to a northerly wind, like the South Shore, Cape, and Islands.
This is a forecast tide level for Boston Harbor. Tides are astronomically high, so even today, without a storm you may see some rising waters in areas that typically see some ponding on days like today. Morrissey Boulevard and Long Wharf come to mind. But the Tuesday afternoon and overnight high tides are where we are most concerned since we’re taking the astronomical high tide and adding a good amount of wind to it. That’s where Boston and several cities could see minor to moderate coastal flooding.
The wind will be howling, but we’ve had storms produce worse wind than this one will. The Cape, like usual, will take the brunt of the wind. We have a high wind watch in effect there that will likely become a high wind warning later today or even later this morning. That’s for wind gusts up to 60 mph. The rest of the coastline will see strong wind as well, but not to the level that other storms, even this year, have produced.
