Bill Danielson bids adieu to winter but has he called time-of-death too soon?
At 1:15 pm on March 20, Earth’s northern hemisphere skidded from winter into spring. And, amazingly, the southern hemisphere swam from summer into autumn at the very same instant! We had reached the vernal equinox, that point where the axis of our Spaceship Earth was aimed neither towards nor away from the sun. At that moment, six months of solar deprivation ended for us, and six months of solar excess set in. Yes, for the next six months, every day will grace us with more sunlight (ignoring clouds) than any day over the past half year.
Of course, we all know that late March and even April can produce wintry weather. In fact, average snowfall for Ingonish in April is about 35cm. But I have a column to write, so I’m saying that winter ended on its appointed date, and here is its obituary (if I’ve exaggerated its demise, I’ll issue a retraction next month):
It is with a feeling of deep indifference that we announce the passing of the winter of 2017-2018 in Cape Breton. The season began with promise, and did produce one or two spectacular moments, but it frittered away most of its time and energy on un-wintry enterprises. A last-minute attempt to assert itself came too late to recover opportunities lost in middle age.
The late winter’s portrait, shown here for Ingonish, illustrates a great deal about its character. Note its ragged profile. The temperature (jagged blue line) tracked an erratic path, zigging up and zagging down in great jumps. This indecision typified the winter’s overall personality.
Comparing the 2017-2018 temperatures (blue line) with long-term mean values (shown by the black curve), it’s evident that the past winter ran a slight fever throughout much of its 90-day existence. Only the first two weeks or so were colder than normal, and even that stretch was interrupted twice, on Christmas Eve and Jan. 5, by leaps far above the norm.
The winter’s most notable and most warmly remembered achievement occurred on Jan. 12 and 13, when temperatures soared to summertime values. At Bay St. Lawrence, the mercury peaked at 20.1C, apparently setting an unofficial all-time January temperature record for the Province of Nova Scotia. Other Victoria County sites were close behind: 18.4 at Cape North and Smelt Brook, and 17.0 at Ingonish, whose minimum temperature on the 12th was +8.6, more than nine degrees warmer than its normal daily January high!
The graph of snow depth for Ingonish (orange line) further depicts the winter’s indecisive temperament. A slow, but steady build-up ended abruptly with the January “heat wave”, but quickly recovered to 31cm on January 18. Thereafter, snow cover mainly declined due to recurrent rain events (shown as green “R”s on the portrait). February actually received more precipitation than the norm, over 100mm in the first week, but most of it came as rain. Ingonish had no snow cover for nearly three weeks in February and early March.
The past winter will also be remembered unfondly for its winds. Days when Cape Breton’s winds gusted over 80km/h are marked with “W”s on the portrait. That’s a lot of days! On March 13, gusts reached 150 at Henry Island, 146 at Grand Etang, and 122 at Bay St. Lawrence. (Thanks, Jonathan Buffet.) On many other days, the winds, if lighter, seemed relentless. For the first two weeks of March, raw easterly winds gusted to 60km/h or more nearly every day.
A proper obituary mentions the family of the deceased. Unfortunately, I can’t do that because I don’t know their names, but they are out there. We might see one of them next winter, or the one after that. I know this because rapid warming in the Arctic is producing weaker and loopier jet streams, which steer weather systems in quirky ways. This past winter, several northbound storms passed just to our west, while others crossed the Great Lakes bound for Quebec, in both cases pulling warm air and rain across Cape Breton. These are quite unusual patterns for winter! But I suspect they may be typical of other winters to come.
The winter of 2017-2018 in one compact diagram! Daily mean temperatures (jagged blue line), snow depth, rainy days (R) and windy days (w) at Ingonish. The smooth grey curve shows long-term mean daily temperatures. Data from Environment Canada.