BOSTON (CBS) – I suspect you’ve probably heard the gossip about a possible late week snow storm here in southern New England, so this won’t be news at this point. And you’ve probably heard various predictions and uncertainties too. No doubt if you’ve been on social media, which is Twitter, I am horrified at what you may have seen.
Let me start with what we know at this point … Later on Wednesday, a coastal storm will form off the coast of Delmarva / Central Atlantic. Abundant snow falls north of the trail of this storm. The air will be cold enough for any snow in southern New England. In contrast to the storm earlier this month, this snow will be very light and loose (with the exception of Outer Cape / Islands) and will therefore accumulate quite quickly and easily.
We also know that Thursday’s storm will NOT be one of those rapidly deepening bombogenesis events here in southern New England, thanks in large part to the storm that transitions to our South Monday. Monday’s storm turns into a monster in the Maritimes, essentially stealing some of the energy available for Thursday’s storm. It will also serve to redirect the jet stream and steering currents quite heavily (to what extent we don’t know for sure until Tuesday, at least …). This means that Thursday the storm will actually weaken as it moves south and likely peak as it passes New Jersey and Long Island. Therefore, we do not expect any strong winds or significant power outages on Thursday.
What is the big thing you are asking? Sounds weak? Well the thing is, you don’t need a monster storm to get a lot of snow. While we have become used to seeing powerful, hurricane-like storms off our coast in recent years, this one won’t fit that bill. What this storm has to offer (something the early December storm didn’t have) is an abundance of very cold air that will be firmly anchored over the northeast. Combine that with an unusually mild ocean for this time of year, and that temperature difference is just enough to create a swath of very heavy snowfall.
Our main concern with this storm also has a lot to do with the cold / dry air that will be in place. This storm has the appearance of a storm in which there will be a very sharp shutdown of “haves” and “have nots” in relation to the accumulation of heavy snowfall. If you have a high pressure area in the north (like this one) and very cold, dense, dry air, the northern edge of the snow plow can literally be eaten away … Billions of snowflakes literally evaporate into the dry mass of air before they hit the ground.
See late March 2018 for a pretty epic bust under similar circumstances. Obviously, that storm was a major underperformer across New England. Or, from a meteorological point of view, a big, fat forecast bust.
While we’re pretty confident that areas in the far south of New England (south of the Pike) will get a lot of snow on Thursday, it’s a lot more difficult in the north.
Snowfall comes from southwest (Connecticut) to northeast (Essex County) between 8 p.m. and Wednesday midnight.
Steady, heavy snowfall pushes furthest north on Thursday at 7-8am and then begins to collapse and weaken, tapering on Thursday noon / afternoon.
Worst way: Thursday morning
Main load of the snow: Thursday 2-10 a.m.
Expect a slight shift in these bands as we focus on the storm trail and the northern edge of the snow blade …
1-3 inches: In the areas where we usually see the heaviest snow! Northern Worcester County, southern New Hampshire (sorry ski resorts)
3-6 inches: From Worcester to Lowell and Lawrence … outer 495 belt northwest of Boston
6-12 inches: Cape Ann to Boston and the immediate suburbs southwest of the city … also the outer Cape and the islands where the snow is not so loose
12+ inches: South Shore, most of CT. and R.I., the chance for severe streaking and snow should build up very quickly, can’t rule out there is somewhere more than 18 inches
Again, there is probably not a major wind threat with storm in debilitating stages in our region … expect northeast gusts along the south coast, cape and islands to be between 35 and 55 miles per hour on Thursday … winds much deeper inland.
The risk of a power failure is low as there is a lack of top-notch gusts of wind and light / fluffy snow
The tides will be astronomically high later this week, so there are concerns about minor to moderate flooding on the coast. The flood of greatest concern would be the Thursday noon (12:52 p.m.) flood with a projected height of 11.3 inches in Boston. In the typically vulnerable areas between 11 a.m. and 3 p.m., splashes and flooding can occur on the coast. Thursday.
As always, we urge you to stay up to date with updates on WBZ-TV, CBSBoston.com and CBSN Boston throughout the week