A Winter to Remember
In the Northeast, February 2015 was a month like no other in our lifetime; January through March Harshest since 1717?
No one who has lived in many parts of the Northeast into Canada experienced a six-week and calendar month as extreme for the combination of cold and snow as we have this late winter. From this writer’s viewpoint in southern New Hampshire, February 2015 was the coldest month ever recorded in nearby Nashua with an average temperature of 12.2 degrees Fahrenheit. It beat out January 1888, which had averaged 12.9F. A record 18 days had low temperatures at or below zero (as cold as 14F below). 25 days remained freezing or below, also a record.
Not far away in Boston, where temperature records began in 1872, February 2015 was exceeded only by February 1934, which brought Boston its all-time record of -18F. Temperatures never rose out of the 30s this year in February in Boston, though it topped 40 four times in 1934.
The cold in February 2015 was not confined to the Boston-Nashua area. It was the coldest month ever in Worcester, Hartford and Portland. It was the coldest February in Chicago and Cleveland, third coldest in New York City and fifth coldest ever in Detroit and Baltimore, both with records back into the early 1870s.
Boston set a record for monthly snow with 64.6 inches in February and 100.4 inches in the 39 days following January 24th. The 110.6 inches for the entire season exceeded the 107.6 inch record from 1995/96. The snow that year was spread out over six months with thaws, not concentrated so much in less than six weeks. The snow blitz and the intense cold is why the snow piles were so high this year. College students were shown on local television jumping out second story windows onto huge snowbanks in their bathing suit.
ONLY 1717 BEAT THIS?
Looking back through accounts of big snows in New England by the late weather historian David Ludlum, it appears for the eastern areas this winter’s snow blitz may have delivered the most snow since perhaps 1717.
That year, snows had reached five feet in December with drifts of 25 feet in January before one great last assault in late February into early March of 40 to 60 more inches. The snow was so deep that people could only leave their houses from the second floor, implying actual snow depths of as much as eight feet or more. The New England Historical Society’s account indicated New Hampshire, Massachusetts and Connecticut were hardest hit, a lot like 2015 in what was known as the year of the great snows.
“Entire houses were covered over, identifiable only by a thin curl of smoke coming out of a hole in the snow. In Hampton, N.H., search parties went out after the storms hunting for elderly people at risk of freezing to death… Sometimes they were found burning their furniture because they couldn’t get to the woodshed. People maintained tunnels and paths through the snow from house to house.”
You may hear or read that increased snow is consistent with global warming because warmer air holds more moisture. In actual fact, 93% of the years with more than 60 inches of snow in Boston were colder than normal.
During the 40 days of snowy weather this winter, we averaged over 11F below normal, and moisture content of the air in the snow region was well below the long-term average. Cooling, not warming, increases snowfall. Indeed, winter temperatures have cooled over the last two decades in the Northeast and the 10-year running mean of Boston area snowfall has skyrocketed to the highest level since snow records were first kept.
The cold continued in March here in New England. The month averaged 5.1F below in Boston and 5.8F below normal in Nashua. There were only four 50F days in March after no 40F days in February in Boston. This compares with seventeen 50F days, eleven 60F days, seven 70F days and one 80F day in March 2012.
JANUARY TO MARCH RECORD COLD
January to March average temperatures were the coldest in the entire record in Worcester, Providence, Hartford and Nashua and third coldest in Boston behind only 1885 and 1895.
In fact, it was the coldest January through March on average in the entire Northeast (the 10 Northeast states and the District of Colombia) in NOAA’s climate record, which started in 1895.
Note how from January to March temperatures in the Northeast have declined for 20 years at a rate of 1.5F/decade.
This season, most areas of central New England had the snowiest mid to late winter and many spots the snowiest winter season on record. In 2013/14, Chicago had its coldest December to March back to 1872 and third snowiest while Detroit had its snowiest back to 1880.
The Great Lakes ice in the two years was the greatest in the record back to 1973, when measurements began edging out the late 1970s, when the world was worrying about a new ice age.
The Adirondacks into southeast Canada in these years usually gets the worst of the Arctic cold. Saranac Lake in February 2015 was 13.6F below normal with 23 sub-zero days, no day reaching freezing and four record lows. March had 15 days zero or below with 10 record lows. Last March (2014), Saranac Lake was 11.4F below normal with 10 sub-zero days and seven record lows.
All of eastern Canada set all-time records for cold, and in Maritime Canada, in many locations, this winter produced more snow than any winter season on record. Charlottetown on Prince Edward Island had a record, incredible 18.1 feet of snow. These were two amazing late winters.
WHAT IS BEHIND THE EXTREMES?
I learned early in my career from the some of the giants in the field like Jerome Namias how ocean temperature pools that develop in conjunction with strong El Niño and La Niña events meander with the ocean currents determine how the jet stream sets up and how strong and persistent it is. This determines how and where extreme winters and summers are for both temperature and precipitation.
A super La Niña in 2010/11 (second strongest in 120 years by some measures) set up warm water in the central Pacific and cold water near the West Coast of North America, which lead to that record warm and droughty 2011/12 central and eastern winter, spring and summer. That warm water came east first to off of Alaska last year leading to the historic winter near the western Lakes and north-central areas (highlighted January’s so-called ‘polar vortex’). Then in 2014 the warm water was carried by the currents southeast to the entire West Coast, forcing the cold to take aim more on the eastern Lakes and Northeast that was at its worst in February.
Similar changes occurred in the Atlantic. Starting in 2007, a warm North Atlantic helped build high pressure in the polar regions and drive Siberian air west to Europe where, in December 2010, the UK had its second coldest December since 1659 in the Little Ice Age.
Though scientists had warned snow was a thing of the past, the UK and much of northern Europe had all–time record snows and cold in five of six years. The North Atlantic turned cold last year and more so this year and Europe turned milder. But a cold North Atlantic means colder and snowier winters in eastern Canada, the Great Lakes and Northeast. The Atlantic thus helped exaggerate the Pacific-driven central U.S. and Northeast cold the last two winters.
At Weatherbell.com, where we use the oceans and sun in our statistical models for long-range prediction, we successfully predicted many months in advance these historic winters. Unless we see major changes in the eastern Pacific, we expect we may make this a threepeat about the time the administration signs a treaty in Paris with other nations at the UN to disassemble our current energy policies to supposedly save the planet from the ravages of warming, which we will show you in the next story is not happening globally and hasn’t for over 18 years.
Joe D'Aleo is a certified Consulting Meteorologist, Fellow of the American Meteorological Society (AMS), former chair AMS Committee on Weather Analysis and Forecasting, co-founder and first Director of Meteorology at The Weather Channel and a former college professor of Meteorology and Climatology.