Dig in, Berkshires: Sizable snowfall headed our way
Some TV forecasters are fond of the term "monster storm," at the risk of hyping garden-variety snowfalls.
But the blockbuster bearing down on the Berkshires and the rest of the Northeast this weekend fits the bill, according to a consensus of government and private weather scientists.
In fact, near-blizzard might seem to be a reasonable description of what's likely to be a blustery dump of a foot or more of snow on the county, with the highest amounts north of the Massachusetts Turnpike.
The National Weather Service in Albany, N.Y., has posted a winter storm watch for all of western New England and upstate New York, and government forecasters in Boston have done the same for the rest of Massachusetts (except Cape Cod and the Islands), as well as Vermont and New Hampshire.
The official definition of a blizzard requires sustained wind or frequent gusts of 35 mph or greater and considerable falling and/or blowing snow, reducing visibility to less than a quarter-mile for at least three consecutive hours.
North Berkshire is most likely to see a 20-inch snowfall, while South Berkshire below the MassPike could get "only" 10 to 12 inches if there's an icy mix late Saturday night into Sunday morning, according to Christina Speciale, a meteorologist at the Albany forecast office. Winds could reach 30 mph Sunday afternoon and evening.
She cautioned against applying the scary blizzard label to the county outlook, except for the highest elevations. Ironically, though, Speciale noted that when winds pick up Sunday night, there could be a technical blizzard because falling snow is not a required part of the definition, while blowing and drifting snow would qualify.
"I wouldn't take it off the table," she told The Eagle, "since for a blizzard, it's not necessary to be precipitating."
At AccuWeather.com, senior meteorologist Alex Sosnowski had no reservations about predicting "an all-out blizzard, causing roads to close and leading to scores of flight cancellations."
Travelers 'will be at risk'
"Those who are on the road through the heart of the snow area will be at risk for becoming stranded for many hours and may have to face temperatures plummeting to life-threatening low levels," he cautioned in his no holds-barred forecast. He listed the New York Thruway, the MassPike and Interstate 91 in the Pioneer Valley as trouble spots, where snowfall rates might reach 2 to 3 inches per hour as blizzardlike conditions unfold.
"Plows are not likely to be able to keep up," Sosnowski stated in an online post. "As the storm strengthens, winds will cause major blowing and drifting of snow, where ice does not mix in."
AccuWeather's Local StormMax computer model projected 40 inches in parts of northern New England. Close to 30 inches of snow is likely to fall in central and northern New York state, while western New England can expect 12 to 24 inches.
Travelers using Interstate 95 in New Jersey, New York and southern New England should see a quick burst of snow and ice late Saturday, said AccuWeather Chief Meteorologist Elliot Abrams. Around the New York City and Philadelphia areas, a few inches of snow might be followed by a buildup of ice before plain rain occurs.But Abrams, co-founder of AccuWeather, pointed out that a southward or northward shift in the storm track by as little as 50 miles might have a profound impact on temperatures and snowfall versus ice accumulation, since a heavy rate of precipitation is expected during the height of the storm.
He urged New England motorists to not underestimate the severity of conditions that might unfold in these areas. Vehicles might become stranded, and occupants would be subject to plummeting temperatures, which are expected to reach dangerously low levels.
The National Weather Service reported that the intense storm coming together over the Tennessee Valley on Saturday afternoon will hook up with a separate storm in the Mississippi Valley. By the time the doubled-up system reaches the Northeast after dark, it will tap into polar air over southern Quebec and a rich vein of moisture from the Gulf of Mexico and the Atlantic Ocean.
Mix, shake well and voila! At least 24 hours of snowfall ending Sunday evening, falling at the rate of a half-inch to an inch per hour.
Some spots could have more than 10 inches of snow by daybreak Sunday, with temperatures in the mid-teens to low 20s.
"The moisture with this system looks so impressive," forecaster Tom Wasula said, with liquid precipitation of 1.5 to 2 inches. That translates to about 15 to 24 inches of snow, depending on the fluff factor of the flakes.
After the storm crosses the Delmarva area of the mid-Atlantic region Sunday morning, it will park briefly just south of Long Island, N.Y., before intensifying even more and heading over Cape Cod and the Gulf of Maine.
On Sunday night and into Martin Luther King Day, winds will increase with some leftover light snow. But northwest winds increasing to 20 mph with gusts to 40 mph will cause blowing and drifting of the snow.
Brace for the polar express
Then comes the polar express, with lows early Monday of zero to minus 10, along with dangerous to life-threatening wind chills of minus 15 to minus 40. On Monday, with schools closed and many public-sector workers on a holiday, high temperatures barely will reach 5 above zero.
No break is expected until a slight "warmup" by midweek.
The extreme cold on our doorstep for early next week is arriving "courtesy" of the dreaded polar vortex — the swirling winds 60,000 feet in the stratosphere above the Arctic sky.
Weather scientists report that the vortex split into three parts this month, creating a severe and punishing winter weather pattern after a prolonged mild spell that ended a week ago.
According to Judah Cohen, a polar vortex researcher at Atmospheric and Environmental Research based in Lexington, near Boston, a split vortex causes prevailing winds that blow from west to east — transporting mild air from the Pacific Ocean over the continental United States — to shift to more north and south. Arctic air can more readily be drawn into North America and Europe, he said.
``The first-order impact [of a vortex split] is that you slow the west-to-east flow and add more of a north-south component,'' Cohen said. ``There's a much greater exchange of Arctic air that's moving south.''
Starting Sunday, temperatures should be up to 25 degrees colder than normal in the Berkshires, as well as points west.
Patriots to play in deep freeze
Temperatures might plunge below zero Sunday in Kansas City, Mo., where the AFC championship game between the Kansas City Chiefs and the New England Patriots will be played.
Computer models indicate that even more persistent and acute cold might develop from Jan. 25 to Jan. 30.
``This is more of a transition period,'' said Michael Ventrice, a meteorological scientist at the Weather Company, owned by IBM. ``We're kicking out the old regime when the Pacific jet was bringing a lot of warmth to the U.S.''
The signal for an extended period of cold and potentially stormy weather is very strong continuing well into February, long-range forecasters said. ``I think you can be very confident,'' Ventrice said.
Once this wintry pattern becomes entrenched, it might be difficult to dislodge.
"These impacts can last four to six, and maybe eight weeks,'' said Cohen, who expects the worst winter conditions in February. He predicted ``intense periods of winter weather becoming more frequent, including more episodes of arctic outbreaks.''
"I think it's going to be a complete 180 in the psyche for people living in the eastern U.S.,'' Ventrice said. ``In Boston, we want the snow now because we haven't had it. By the time this is over, we're going to be ready to be done.''
Information from The Washington Post was included in this report.
Clarence Fanto can be reached at email@example.com, on Twitter@BE_cfanto or at 413-637-2551.
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