Good evening everybody, we’ve got a bone-chilling evening ahead, but at least the wind is down! Then we have a pleasant Sunday with sunnier skies early, and mid to high clouds overspreading the region in the afternoon, producing that silvery snow sky with which we’re all familiar. We cloud up overnight and an impactful snowstorm arrives by afternoon, maximizes in the evening, and lingers in some fashion on Tuesday, so grab a beverage and let’s jump into the details below.
As for this comprehensive report, be sure to scroll down and up to read the sections you want, or stay for the whole show, it’s up to you… have it your way!
And please do share this information with your friends and family in the area so they can be updated, as this storm looks impactful for sure. Not a blockbuster, but a solid Nor’easter worthy of some prep and heads up.
TONIGHT THROUGH SUNDAY NIGHT
As strong high pressure builds in from the northwest up near James Bay and southeast into our region, winds continue to lighten, which has allowed Wind Chill Advisories to expire, despite how numbingly cold it’s going to be.
We can expect lows under mostly clear skies to drop below zero just about everywhere, somewhere between -10 in SVT and -2 in the Pioneer Valley and points south and east.
For tomorrow, we should start off sunny, and temps will rise into the low to mid 20s for highs, with some upper 20s possible down in the Hartford area. After a mostly sunny morning, mid and high-level clouds will increase during the afternoon, and start to obscure our star, which interestingly is swimming in the cosmic sea, as are we, but I digress!
Winds should be light to calm. Clouds will increase, thicken and lower tomorrow night as the primary storm tracks east into the Ohio Valley. Lows should drop into the low to mid teens for a balmy night of fun and frivolity.
NOR’EASTER SETUP
By Monday morning, the original/primary low center will be weakening as it crosses into southwest PA and northern WV, as a secondary low pressure system develops somewhere near the DelMarVa Peninsula and southernmost New Jersey along the coastline.
At the same time, our upper level low will be drifting east, just to the west of these surface systems, and will be in the process of taking on a neutral tilt as it crosses into Pennsylvania. As the upper and secondary surface lows interact, the secondary will strengthen as it lifts northeast off of the coast and tracks toward Nantucket Island.
At the same time, we’ll classically have a cold, strong high pressure system north of us over Quebec Province which will help produce an increasing pressure gradient between the low to the south and the high to the north.
With clockwise circulation around the high and counterclockwise circulation around the low, we will generate our moist east and northeasterly winds off the Atlantic Ocean, giving rise to our Nor’easter by Monday afternoon.
In addition, by Monday night a strong easterly and east-northeasterly low level jet streak (i.e. a faster river of air about a mile above our heads) will be helping to slam moist air off the ocean and into central MA and western MA, as well as northern CT.
This should help produce a heavy thump of snow over Worcester County, northern CT and southwest NH, as well as the western hilltowns and eastern Berkshires. The biggest snow impacts will be experienced by mid to late afternoon and especially Monday evening and night until the early pre-dawn hours when a dry slot or area of drier air aloft entrains into our storm system, which will cause lighter snows and may change the crystal type from big, fluffy, stackable dendrites to snowflake types that don’t accumulate as well or as high, so that is something to watch for.
Also, the CT River Valley (where as Bill Dwight likes to say, snowstorms come to die, lol) may experience a phenomenon called “shadowing” so let’s take a detour into that for a minute.
SHADOWING
To start, rising air in a saturated-or-moist-enough atmosphere creates precipitation eventually, whereas sinking air tends to dry out precipitation shields, or the air below the downward-moving parcel, generally speaking.
In the valley of western MA (and northernmost CT and southeasternmost VT sometimes) if a Nor’easter passes to our south and produces a more easterly wind (traveling from east to west), we can get what’s called shadowing.
What happens is moist easterly flow slams into the Worcester hills and dumps heavier snows there, and this can also last into the hilltowns of eastern Franklin County and eastern Hampden County (and to a lesser extent, the towns of Pelham, Ware and Belchertown in eastern Hampshire County).
Then, as the air drops off and descends into the valley floor, that subsidence (which means sinking air) dries out the snow shield, and causes much lighter snow to fall, reducing accumulations, and this could happen with this storm system.
Finally, that same air keeps trucking and rises back up into the western hilltowns and eastern Berkshires and heavier snow picks back up, if the flow is strong enough.
TIMING/ONSET
I believe we could see some flurries in northern CT by late Monday morning, but the first periods of steady snow should arrive between early to mid afternoon on Monday.
Snow may be light at first, but should quickly become steady by mid to late afternoon especially south of the Route 9 corridor in WMass and CMass, and then by and just after sunset, we should all be snowing, and it will come down heavily at times as our front-end thump gets underway.
This will cause travel to go downhill, so if you have to commute home from work, or otherwise travel, give yourself extra time, or alter plans if possible.
Snow will fall heavily at times Monday night, and by the pre-dawn hours of Tuesday sometime, snow may become light to moderate, and intermittent, and I will try to get more clarity around this as we get closer.
Snow may linger on Tuesday as the secondary low isn’t going to be in a hurry to get out of here given the fact that it will have atmospheric traffic to its east and northeast due to blocking high pressure.
By Tuesday evening, the storm should be out of here.
WIND
As I said, the pressure gradient between the Quebec high and the coastal low will produce northeasterly and easterly winds that will likely gust 30-40mph at times during Monday night into Tuesday, which will cause considerable blowing and drifting of newly-fallen snow, and reduce visibilities if you must travel Monday night, which is not advised. Wind should swing from east to northeast to north by Tuesday, and lighten during Tuesday.
AMOUNTS
I think that assuming the low center doesn’t hug the coast and pass over Martha’s Vineyard or west of Nantucket (which we can’t rule out yet) Worcester County and northeast CT should get hammered by this storm, and some power outages will be possible there with accumulations of 10-14″. This may extend into easternmost Hampden County as well as the high terrain of eastern Franklin County.
I think the Pioneer Valley from Brattleboro down to Hartford will see more like 5-10″ of snowfall, with the lower end of that range possible if the downsloping/shadowing effect really sets up.
I think the western hilltowns and Berkshires up into SVT and down into NW.CT will be a bit further from the storm, but should see more like 8-12″ of snowfall. Southwest NH should fit into this range as well.
BUST POTENTIAL
There are a number of uncertainties with this system, and the exact direction of wind and for how long it persists will impact this shadowing effect I mentioned, and hence valley snow amounts.
We may see more than one low center form off of the coast and meander or wobble around to our south Monday night and this may impact the dry slot, how fast it gets in here, where it does, and how it breaks up or keeps in tact the precipitation shield overhead.
How strong will our upper level ridge be to the west of our neutrally-tilting trough, and at what longitude and latitude does the upper low center/trough go neutral will help to steer the secondary surface low closer to or further away for the coast, potentially impacting snow amounts.
All that said, I doubt these amounts would go up from here (though you never know), but this storm could bust LOWER, and especially so in the valley and areas north of the MA/VT-MH state line, so stay tuned.
TUESDAY NIGHT THROUGH THROUGH THURSDAY
Snow showers should abate Tuesday night with lows in the low to mid 20s. This storm is not existing super fast, so lingering clouds will be around on Wednesday with highs in the upper 20s to low 30s and lows in the upper teens to low 20s.
Thursday looks like a sweet day with highs in the low to mid 30s under mostly sunny skies with low sin the 20s as clouds increase.
FRIDAY AND SATURDAY
A couple of systems may affect us during this time period. Notably, a storm will pass well northwest of us Friday, but could send a secondary system into our region that forms along the parent low’s cold front, and that may bring a mix of rain and snow showers Friday and Friday night.
Additionally, a sneaky second wave may form for Saturday night and bring some snow to the region, mainly south of the Pike in WMass/CMass and northern CT.
ANOTHER SNOWSTORM NEXT TUESDAY?
Yes, it’s possible folks! We’re in an active pattern, and another coastal snowstorm could visit our shores by early the following week.
All this to say, please stay tuned for updates, the next one being tomorrow morning as we get ready for the plows to rumble down our streets and over our hills and dales as enter the month of February.
Have a great night!