The warm weather moved in as expected during the latter half of last week, but a strongly stratified atmosphere kept the really warm air from mixing down to the surface. Combine this with some low-level moisture and you end up with plenty of clouds and fog that helped to keep temperatures cooler than predicted. Temperatures were still warm enough that our fairly light snowpack took a bit of a beating and the forecast is not that promising for any significant snow before Christmas.
This forecast period will begin with an area of high pressure dominating our weather. This high is from the Arctic, but has already been modified, which means temperatures won’t be that cold. We should expect to see high temperatures in the -8 to -10 C range with overnight lows around -18 C. This high looks like it will move fairly slowly to the southeast over the week, which means that skies should be mostly clear and winds on the light side.
A weak disturbance will try to move through our region over the weekend, but I think at best we’ll only see a mix of sun and clouds with only a few light flurries possible. A second area of high pressure will then move in behind this system, bringing more clear skies and temperatures continuing to be right in the middle of the usual temperature range for this time of the year.
We’ll then have to watch a developing storm system that is expected to move in off the Pacific and track across the northern Prairies next Tuesday and Wednesday. Confidence in this part of the forecast is low, but it currently looks like most of the energy from this system will stay well to our north. We could see some light snow on Christmas Eve with this system, along with some fairly strong southwesterly winds ahead of the system and then northerly winds once the system moves by, dragging a cold front through our region on Christmas.
Usual temperature range for this period: Highs, -18 to -2 C; lows, -28 to -11 C.