The Canadian Imagination

What it means to be Canadian; examining and reworking Canada as a nation.

Thursday, December 04, 2008

The great white north

Knowing that her decision is only the prologue, Governor-General Michaƫlle Jean has chosen the cautious route, giving the existing government every possible chance to demonstrate that it can regain the confidence of the house within a reasonable amount of time. Parliament is now prorogued until January 26, and we have seven weeks of election-style campaigning and message-spinning ahead of us. The Conservative coffers are deep. Be prepared for a quick switch from Christmas and Boxing Day commercials to a heavy serving of partisan commercials.

So let's take a quick break and talk about the weather. Remember the weather? We used to talk about it all the time whenever we were not talking about hockey?

Environment Canada has issued its three-month forecast for the coming winter. If you read between the lines, it basically says: We don't have a clue ... but it can't possibly be as bad as last year?

Don't blame the weather forecasters for this one. In the absence of any major Pacific event, our knowledge of meteorological science is simply not good enough to determine which of several localised weather features will end up being the dominant one over this or that region of Canada. The meteorologists themselves point out that over the past month, every known predictor has swung wildly from one end of the scale to the other.

Yet I, being fearless (or foolish, or both), will venture one prediction.

We know that as of this particular decade, our global temperatures have been steadily rising. While the specific effects of this vary from region to region, in Canada we can fairly clearly link two observed phenomena: the permafrost is melting, we have an increasingly ice-free Northwest Passage and Great Lakes region. Even this year, where winter seems to have arrived in mid-autumn and nearly all of Canada is likely to be a six-months-of-snow nation in truth, the Northwest Passage is only starting to freeze over, and the Great Lakes have not yet closed for the season.

Areas to the lee of the Lakes have long known about the "snow machine", where the dominant northwest winds which bring decent (if cold) weather to most places instead draw up moisture from the Lakes while they remain unfrozen, and deposit it as amazing accumulations of snow in streamers. It is nothing, caught under such a streamer, to shovel out 25, 50, 75 centimetres of snow in a 24-hour period. Two weeks ago, Arkona managed 80 centimetres in a mere 12 hours. So long as the temperature is within a degree or two of freezing and the Lakes are unfrozen, the snow will come. There can be no break until the Lakes freeze over.

The warmer the temperature, the longer the Lakes remain unfrozen, and the longer the snow machine can remain stuck on the "on" position. For this decade at least, a mild winter is still one that averages around the freezing temperature: and thus the milder the winter, the longer the period during which the snow machine will be active.

A similar, larger-scale mechanism is at work in the far north, where early winter winds pick up moisture from the Arctic Ocean and Hudson Bay while they remain unfrozen ... but this is not usually an issue for the depths of winter. Windstorms last fall through spring, but the heavy snowstorms tend to be limited to late autumn and the early part of winter.

Therefore, for significant parts of Canada, winters which do not dip as far below the freezing mark as they used to will also increase the overall amount of snowfall in areas leeward to any large bodies of water.

Call it an investment in our continued cardiac health!


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