Despite not a lot of confidence in last issue’s forecast, the weather models actually did a pretty darned good job. We saw the mild temperatures early in the period followed by the slight cool-down. The models were then showing milder temperatures moving in for the first half of this week, with the chance of a storm system ejecting out of the U.S. southwest.
This is where we begin this forecast, and unfortunately, as I write this, there is a lot of uncertainty about this mid-week storm system. Weather models have been all over the place this past week with this storm system, sometimes weakening it and pushing it to our north, while at other times indicating it will stay strong but pass by well to our south. As with any early-winter storm systems, we will need to keep an eye on this, but it looks like most of the energy and snow will stay to our south and east.
Once this system moves off, the weather models show a second area of low pressure over the Yukon dropping southeastward and bringing with it another chance of snow by Friday. Usually we would see a good push of cold air behind a system like this, but the weather models point toward a building ridge of high pressure moving in over the weekend. This ridge has the potential to push temperatures above the freezing mark, especially if any areas remain snow free.
To start December, the weather models show an area of high pressure edging by to our north, bringing sunny skies and slightly cooler temperatures. Daytime highs are forecast to be in the -5 C range, with overnight lows dropping to around -15 C. This little cool-down is not expected to last long as it looks like another upper ridge will quickly rebuild, bringing a return to daytime highs around the freezing mark by the second half of the week — which, by the way, is at or even slightly above the usual temperature range for this time of the year.
Usual temperature range for this period: Highs, -12 to +1 C; lows, -21 to -7 C.