Saturday, November 20th 2021, 8:47 pm - Canada's reservoir of cold air in the Arctic took its time to really cool down, especially after a well-above average few weeks.
For a month serving as the lead-up to winter, November hasn't really featured the kind of cold we'd normally expect this time of year.
Certainly, there have been some chilly patches, but largely offset by relatively mild stretches in most places.
The reason for the late onset of true winter-like cold is that the Arctic, a major reservoir of cold air for the country, has been running something of a fever in recent weeks. Numerous communities were delayed in seeing their first zero-degree daytime high, and in fact, parts of Nunavut experienced a mean temperature anomaly nine degrees above normal for this time of the year.
However, that's soon about to change. The cold has, finally, been building, and now there's enough in that Arctic reservoir to spill down into the rest of Canada, as soon as this weekend.
The first fore will be into the Prairie provinces, though the cold air won't be evenly spread. Parts of western Alberta will still be able to get away with a few above-zero daytime highs, though none higher than the mid-single-digits.
Temperatures rapidly drop off as one moves into central Saskatchewan and parts of northern Manitoba. No one in either province has a realistic chance of seeing temperatures above zero, and in some areas, the wind chill will make it feel like -20.
Looking beyond, Wednesday will be another frigid one across the Prairies, and through the week, the worst of the cold will migrate eastward, blanketing Ontario and Quebec by Friday.
We should stress that it won't be as cold as the Prairie provinces, but it will be uncomfortably cold for many.
Another thing to consider: The Great Lakes remain largely unfrozen, so when that frigid air arrives, combined with cold winds, the result is likely to be rounds of lake-effect snow squalls, with the snow sticking around for longer than in previous episodes.