Once again, the weather models did a pretty good job over the last seven to 10 days. I think I should point out that when I say “weather models,” I am referring to the fact that I look at the different models and combine each, sometimes using what one model predicts, other times ignoring one model in favour of a different one.
It is a bit of a tough forecast for this period for a couple of reasons. First, the models have been consistent from run to run, but every day or two they do a radical jump in their forecasts, only to settle back to the original forecast. Overall, the models have been showing a quick flow across our region with relatively weak systems. This makes the timing of different features tough to get right. A small change early on becomes a large change further out.
The first half of this forecast period will be on the quiet side, with weak high pressure in place. This will give us sunny to partly cloudy skies with relatively light winds and daytime highs in the -5 C range, with overnight lows dropping to around -12 C (warmer in areas with little snow cover). To our west, an area of low pressure will be digging to the south, which will allow for an upper ridge to build over our region. This will help to boost temperatures to above freezing by the weekend (March 6-7). I would not be surprised to see daytime highs make it into the +5 to 7 C range.
This is where things get a little muddled. To start off the week of March 8, the weather models have been jumping back and forth between a dry but slightly cooler period and a significant storm system impacting our region.
Let’s examine the storm system prediction. The models predict that the area of low pressure, which was digging south over the weekend, will spin up a strong area of low pressure over Montana on Monday. This low will then track northeastward through southern Manitoba, exiting the region by late Tuesday. Should this pan out, we could see a messy mix of rain and snow with water-equivalent amounts coming in around 10 mm. Behind this low, we would see colder air being pulled down from the north, dropping temperatures back down to more seasonal values. Once again, I should point out that there is not a lot of confidence in this part of the forecast.
Usual temperature range for this period: Highs, 0 to -13 C; lows, -25 to -9 C.