A MORE NORTHERLY PUSH OF MILDER AIR ALOFT MORE LIKELY THAN NOT TO PUSH SLEET AND FREEZING RAIN FURTHER NORTH INTO WMASS… HEAVY SNOW, SLEET, AND SOME FREEZING RAIN EXPECTED STARTING TOMORROW NIGHT AROUND 5-7PM, BECOMES HEAVY OVERNIGHT AND CHANGES TO ICE SOUTH OF RT. 2 BY EARLY SUNDAY AND LASTING THROUGH THE MORNING, CHANGING BACK TO SNOW AND ENDING BEFORE SUNSET… TOTAL SNOW/SLEET ACCUMULATIONS MAY NEED TO BE REVISED DOWNWARD A BIT… (7:40pm Friday)
Good evening everybody, I want to start by welcoming the approximately 700 or so new folks who joined the page over this past week.
Welcome! PLEASE NOTE that if I don’t snow in your feed, I post every single day on every single storm or weather event, so just visit the page directly, and I’ll be here. I can’t control the algorithm nonsense anymore. I also use ALL CAPS for headlines and section headers, which means I’m not yelling at you. :-)
FORECAST CHANGES: LESS SNOW, MORE ICE
Yes, yes, I am with you. I want an old-fashioned snowstorm too, with all snow, and two feet. It’s not happening south of Route 2, and possibly not even south of the MA/VT-NH border.
But Dave, why? Good question!
THE MID LEVELS ARE KEY
It’s important to note that when we talk of low pressure centers, we usually refer to the surface low. However, a low pressure system is a VERTICAL system, with multiple low centers at different heights in the atmosphere above our heads, and rarely do all of those differing low centers stack up on top of each other over the same longitude and latitude coordinate point on the Earth’s surface.
I have a LOT to learn, and always will. Studying the weather is a humbling enterprise incredibly so.
Having said that, one thing I noticed after this morning’s post is how the low center about a mile up was positioned more to the north and west of the surface low.
This, along with a more southerly “dig” of energy south of the surface low, combined with a more robust high in the Gulf all allowed milder air a mile up to set up more northerly over the Plains than originally expected. This “constellation” of atmospheric features (pressure and temperature at surface and a mile up) will likely carry all the way to the coast as our storm moves through our region. This will help us to likely see a bit more in the way of sleet (and even freezing rain for a time along and south of the Pike, and especially down in northern CT).
LOW LEVEL JET STREAK TRENDS STRONGER
Correspondingly, as you can see in the attached map of the southerly low level jet, it will be ripping between 60-70 knots from south to north a mile up over our heads. This is STRONGER than indicated yesterday, which means there’s a better chance for milder air to push deeper into WMass toward the Rt. 2 corridor, causing us to experience more heavy sleet, which may start even before sunrise Sunday morning, as opposed to after. This means some extra hours of sleet, which can cut down accumulations.
As you can see in the next map, temperatures at a mile up are expected to increase to over the freezing mark into southern parts of WMass. I did a crude drawing of where I roughly think precip types will set up. It’s not a perfect gradient, just like snowfall accumulations don’t fall in perfect gradients.
It’s possible sleet could mix into SVT for a little while, for example. We shall see how it transpires. It’s going to snow, sleet and freezing rain from northern CT northward Saturday night through Sunday.
NARROW RIBBON OF FREEZING RAIN
Now that we’ve established that we could see a further north intrusion of milder air aloft, that means that a narrow ribbon of freezing rain may develop across northern CT (highest chancer is in Tolland and Windham Counties) into eastern Hampden County and southern Worcester County. This could push as far north as the Pike, or possibly even Rt. 9, though I don’t think it gets that far north. The Arctic cold will be hard to displace.
For folks who do get under a band of freezing rain, it could accrete up to a quarter inch of ice, and possibly as much as a third or even a half inch, which could cause not only very hazardous travel, but also some power outages, so folks in those areas should take note.
DON’T TRAVEL SUNDAY IF YOU CAN
Travel is going to be terrible, and ill-advised, especially in the morning into the early afternoon after heavy snow, sleet and freezing rain falls.
Let the crews do their work if you possibly can, though I know some people have to work. If you do, give yourself tons of extra time to get from point A to point B, and bring with you in your vehicle a small shovel, some sand, cardboard, potable water, and non-perishable snacks in case you get stuck, along with a fully charged cell phone.
SNOW/SLEET AMOUNTS
For the northern counties of CT excluding Litchfield, central and eastern Hampden County into southern Worcester County along and south of the MassPike I am going to revise downward to 4-8″ of snow and sleet for accumulations from this system. These areas will see longer periods and durations of sleet and possibly freezing rain after a snow thump Saturday night into the pre-dawn hours of Sunday morning. Up to a quarter to half inch of freezing rain ice glaze is also possible, especially in northeast CT in the southern portions of Hartford, Tolland and Windham Counties. If we get less ice, then you will see the higher range of snow/sleet, and a few folks could see up to 10″ in that case, but this feels reasonable right now.
For northwest CT (Litchfield County) up into the southern Berkshires/Taconics, into the western hilltowns of Hampden County, as well as through central and eastern Hampshire, central and eastern Franklin County, and Worcester County north of the Pike but south of the Rt. 2 corridor, I think 8-14″ of snow with periods of heavy sleet looks plausible right now. Freezing rain may mix in a little bit too, but the icy precip type in these regions should be mainly sleet.
Where I believe it will remain all snow in the northern Berkshires, northern Taconics, the western hilltowns of Franklin and Hampshire County, as well as north of the Rt. 2 corridor up into southern VT and southwest NH, I think we will see 12″-18″, with 2 foot plus amounts in the the high ski peaks of the southern Greens. You can see precip accumulation map shows we get between 1.25-1.5″ of liquid water. The black circle shows where the heaviest snow is expected.
Also, the fact remains that the east-facing slopes of the southern Greens are going to be the perfect combination of intense lift, heavy precipitation, super cold air at all levels, and so up to even 3 feet is possible in those high peaks.
SNOW AND SLEET REMOVAL
There are two schools of thought, and one involved WORK and the other CLEANLINESS. If you want a clean set of walkways and driveways and pathways, wait to let the ice fall on the snow, then you’ll get a clean swipe to the ground.
However, that will be much more work, especially with sleet on top which is heavy for sure. So you might consider waking up (ahem, and measuring and reporting your snow accumulations to your friend Dave!) and shoveling immediately. Then let the sleet and ice fall, then remove that when it’s all done. That will break up the work, and make it more tolerable.
Do whatever feels best, but those are a couple of thoughts I wanted to pass along.
BRUTAL COLD SUNDAY NIGHT INTO MONDAY WITH DANGEROUS WIND CHILLS
I will produce as comprehensive a report as I can for your tomorrow afternoon before the storm arrives with all concerns and hazards, but just know that northwest winds will gust over 30mph Sunday night into Monday as Arctic air drops temps below zero Sunday night, and keeps them in the single digits to near zero Monday. With winds this will cause very dangerous wind chills up to 20-30 below zero, so prepare accordingly. Monday night goes below zero as winds slacken.
——-
WINTER STORM WARNINGS ARE NOW POSTED FOR LITCHFIELD COUNTY OF NW.CT, BERKSHIRE COUNTY, AND ALL OF SVT… WINTER STORM WATCHES CONTINUE FOR THE REST OF THE REGION… 60 HOURS OF FULL-ON ARCTIC WINTER WEATHER STARTING SATURDAY EVENING LUMBERS TOWARD NEW ENGLAND… (7:05pm Friday)
Good morning everybody, as I posted an hour ago or so, our overnight system weakened considerably and basically fizzled over the valley. It did lay down some very light accumulations in spots mainly over the Berkshires or SVT. Some more snow showers or flurries are possible today into the early afternoon, but little if any additional accumulation is expected.
Despite some colder signals that came in overnight (which could keep more of us in the all-snow category for this weekend’s storm north of the MA/CT border) I am leaving my thinking alone and letting it stand for now.
Instead, I will post a summary of upcoming events below, and you can refer back to my Thursday 7:25pm post for “the book” if you need more nerdy detail.
My plan going forward is to use the morning’s to summarize, and use the late afternoon/early evening’s for new long-form detailed posts, so we’ve got two more of those coming before the storm lands on our hilly shores. Ok, enough incessant blabbering, Hayes, get to the Summary!
SUMMARY:
–For today, expect mostly cloudy skies with a few sunny breaks possible. Highs will be reach the low to mid 30s
–A cold front passes through later this afternoon, and Arctic air starts to seep into the region
–Expect partly cloudy skies with lows in the low to mid teens as we cool down
–For Saturday, we start off partly sunny, but will quickly cloud over by noon or early afternoon
–Highs tomorrow only reach the low to mid 20s, and snow showers are possible north of the Pike before sunset
–Low pressure will track northeast out of the Mississippi and Tennessee Valleys, but not before picking up additional Gulf of Mexico moisture
–This low will track to the Appalachians near Virginia and spawn a secondary low south of Long Island, which will track east to Cape Cod
–Snow will overspread the region between 5-8pm tomorrow evening, and become steady and heavier by 10-11pm
–Travel conditions will go downhill quickly as a very cold surface will have been established and will allow for snow to stick readily to all surfaces
–Lows tomorrow night will drop into the upper teens with heavy snow falling 1-2″ per hour at times as banding sets up thanks to milder air pushing north, and Arctic air draining south
–These two air masses makes a #SnowSandwich over our region, but we have to watch the lower level jet a mile above our heads
–The potential still is there for a period of heavy sleet to take over
–This sleet shield could make it as far north as the Rt. 2 corridor, but I am starting to wonder if it only makes it to the level of the Pike or Rt. 9 corridor. I will update this tonight
–Any sleet that does occur falls heavily Sunday morning, and then changes back to snow as the low pulls east, wrapping in much colder Arctic air at all levels and sending that mild nose of warmer air packing
–Additional snow accumulations will be possible Sunday afternoon before it quits around the start of the Pats game (6pm-ish for you non football fans)
–CONCERN: I am concerned about mesoscale (i.e. localized) heavy snow banding in the deformation zone over the Berkshires, Taconics and SVT
–Sometimes the ends of these storms produce quasi-stationary heavy snow bands that sit and dump on our hill terrain west of the CT River
–This could happen again and seriously enhance snowfall amounts there
–Assuming that does not occur, I think most of us see 10-18″ of snowfall with some sleet mixed in
–A bit less down in northern CT where more icing could occur, and up to 2 feet north of the Rt. 2 corridor
–I will post more detailed amounts this evening, as I did last night, but it’s either side of a foot for most of us. It’s a lot of snow :-)
–After Sunday highs in the teens to low 20s, we PLUNGE
–Sunday we drop into the single digits below zero, and the northwest winds pick up and gust to 30mph or so at times, dropping wind chills way below zero
–Temps crash 30 degrees in some spots overnight, and any standing water, sleet, etc. will freeze in place
–The saving grace is that much of the snow should be powdery in nature, so a flash freeze doesn’t impact a snow type that contains less water, generally
–Still, clean your spaces up after it quits tomorrow if at all possible
–By Monday morning, wind chill readings will be 10-35 below zero from northern CT to SVT high terrain. BRUTAL ARCTIC COLD
–Monday highs? Single digits, and Monday lows will be singles below zero again
–We moderate next week, and a mix of snow and rain showers are possible by mid week
Have a great day, and stay tuned for my updated report this evening!!