Sunday, February 8, 2015

Counterintutive, But, Is New England Extreme Winter Weather Linked To Climate Change?

Dwight Johnson of Worcester, Mass clears
his roof on Friday for the second time this winter in anticipation
of the next big snowstorm now arriving in the region.
Photo by Paul Kapteyn, Worcester Telegram and Gazette.  
New England remains on tap for continued extreme winter weather for at least this week and probably beyond.

As I hint at in the headline, there might be a weird connection to climate change. I'll get to that in a minute.

But first, I'll get into what's going on today and for the next week, since that's the immediate concern.

Forecasts haven't changed a whole lot since yesterday.

Once again, northeastern Massachusetts and the areas around Worcester, Mass are in the bullseye for the deepest snow with the winter storm that is starting in fits and starts but will gain momentum tonight and Monday.

With an Arctic front stalled to the south of New England, and relatively modest storm systems rippling along the front, the snow will just keep on going. The most substantial of the storms will come along tonight and Monday, hence the heaviest snows in southern New England.

With strong east winds coming off the ocean north of the storm and the front in Massachusetts, the snow will really come down near and just north of Boston, and on toward Worcester. Those areas are the ones that really seem to keep getting the most snow in this persistent, very weird weather pattern.

The National Weather Service in Taunton, Mass. near Boston is referring to that blast of wet, cold east wind as a "moist, cold conveyor belt.... which will serve as a fire hose transporting copious moisture into the cold airmass over southern New England."

That's why the expect to get so much snow.

 There's about two feet of snow on the ground, locally more in the area due to get the heaviest snow. (They've had five feet or more of accumulation since the third week of January, but snow tends to settle.)

The snow banks are huge, and I have no idea where they're going to put the snow.

In the Capitol District around Albany, N.Y and much of eastern New York for that matter, the winter storm warning calls for generally 9 to 18 inches of new snow by Monday night.

The southern halves of Vermont and New Hampshire will get into the act with the heavy snow, with ten to fourteen additional inches forecast through Tuesday morning.

When I say "heavy snow" I don't mean it will snow super hard. The storm is just lasting a long time, so light to moderate snow going on for more than 48 hours will really pile up.

Areas closer to the Canadian border in New York, Vermont and New Hampshire are still expecting maybe six to ten inches of additional snow.

Areas of Maine hardest hit by the recent snows will fare OK with this one. They're expected three to six inches of snow.

ANOTHER STORM?

We're still looking at another storm that would dive down from Canada midweek. Like many of the past storms, this one has the potential to blow up into something pretty big along the coast, which could dump a LOT more snow on eastern New England.

Oh, boy, I bet they're excited around Boston!

There's still a lot of questions as to whether that storm will get big and snowy, or whether New England will get a reprieve of sorts and only get light snow.

There's more certainty that behind that storm, perhaps the coldest air of the year, and perhaps the coldest air in decades could plunge into New England

Some runs of the American computer forecasting models are ridiculous, hinting at temperatures in the upper 20s to low 50s (not a typo) below zero in northern New England and teens and 20s below in southern New England

Before you start panicking the American model always overdoes cold waves this far in advance, so it won't be nearly as bad as they're suggesting.

But, there's a chance thing could be brutal over Valentines weekend, rivaling epic, historic cold waves in 1994 and 1979. Make plans now to cuddle up with your lover. Or get a lover --FAST!

If predictions pans out, it would mean lows in the 25 to 40 below range in much of northern New England, and single number and teens below zero in southern New England. High tempertures wouldn't get above zero in much of the region in this scenario.

Just for comparison's sake, the all time record low for any winter day is 18 below in Boston, Mass., 26 below in Hartford, Ct., 17 below in Providence, Rhode Island, 24 below in Worcester, Mass, and 30 below in Burlington, Vermont.

The coldest readings on record in New England are -50 at Big Black River Maine on Jan. 16, 2009, and another -50 at Bloomfield, Vermont on Dec. 30, 1933.

I don't think it will get that cold in any of these places this coming weekend, but it could get within a few degrees of those readings. Plus, sometimes all the computer models back down as we get closer to the event, and we just end up with frigid air, but not record breaking readings. We'll just have to wait and see.

This incredible weather pattern that has been in place since late January and will continue for most of February. I would rate it as unprecedented in southern New England, and extreme, but maybe not unprecedented in northern New England.

COUNTERINTUTIVE, BUT CLIMATE CHANGE CONTRIBUTING TO WINTER BLITZ? 

I know, Duh!. Extremes snows and record cold doesn't exactly make you think you're in the throes of global warming, but hear me out.

There have always been extreme weather events, of course. Records are made to be broken.  But the frequency of previously unheard of storms and temperature extremes does make us think about climate change

Is climate change making the jet stream contort into
big ridges and dips, like shown here? If so, extreme weather,
like the current New England winter blitz,
big storms and big heat waves might be increasing.  
I've mentioned this before, but climate scientists, digging into the gory details of climate change, have noted that the jet stream has tended more and more to develop bigger ridges poking way to the north, and bigger dips diving way to the south. And these patterns seem to be getting "stuck" in place more often.

Extreme jet stream bulges to the north cause record warmth, and extreme dips to the south cause record cold, even if the world overall is gradually warming.

And if the jet stream gets stuck in place, storms take the same path over and over again, hitting the same spots, causing record rainfall and snowfall.

New England has been the victim of recent weeks of an extreme southward dip in the jet stream that has become stuck, which is why the snowstorms keep targeting New England, areas near Boston in particular.

There's been an unusually flurry of stuck weather patterns, stuck jet streams in recent years. The California drought, which has dragged on for three years now (and is only getting partial relief from heavy rains this weekend) is the child of what has become known as the "ridiculously resilient ridge" that has more less stayed put over the West Coast for three years.

Super Storm Sandy came ashore in New Jersey with its devastation in 2012 due to an extremely odd and serpentine jet stream configuration that sent the storm smahing into the East Coast instead of roaring harmlessly northeastward into the open Atlantic, which is normally what happens.

Given how we're shivering, a lot of us might not remember the incredible heat wave of March, 2012, where dozens of cities in the Midwest, East Coast and southeastern Canada had all time high readings for March in the 80s over the course of a week due to an incredibly large northward bulge in the jet stream.

I want to caution that the "global warming is screwing with the jet stream" theory is intriguing, but not yet proven.  The science is settled on the fact global warming is occurring, but not totally settled yet on what effect the warming might be having on the jet stream and weather patterns.

Plus, there are always natural phenomenon at play which also periodically affect weather patterns. These natural cycles also influence extreme weather events and storms.

Of course, few winter weary New Englanders are worried about the jet stream at this particular moment. Who can blame them? The immediate crisis is just finding a place to put all this snow as they struggle to remove it from their driveways.

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