As we’ve seen more than once this summer, last week’s upper low ended up being stronger than expected and as a result, it moved slower. The biggest difference in the last couple of upper lows is that instead of bringing clouds and steady rain, they are the focal point for thunderstorms. The rest of last week’s forecast played out pretty well; unfortunately, this week’s forecast is not as promising in the sunshine department.
The key words for this forecast period are “low pressure,” as a couple of slow-moving systems will impact our weather. It doesn’t look now like either of these lows will directly hit us, but they will be close enough to bring us clouds along with the chance of showers and thundershowers.
The first low will track across North and South Dakota on Wednesday and take until Friday to pull off into Ontario. The majority of the precipitation looks as if it will stay well to our south, but we will see cloudy to partly cloudy skies. The best chance for showers or thundershowers will be on Thursday and Friday, as the main upper-level support for this low moves across southern Manitoba. With the clouds, temperatures will be on the cool side, with daytime highs expected to be in the low 20s and overnight lows in the low to mid-teens.
We should see a return to sunshine over the weekend as high pressure builds in from the north. While it will feel warm under the sun, air temperatures are forecast to remain fairly cool, with highs remaining in the low 20s. By Sunday, a developing low to our northwest will help to create a southerly flow across our region. This will begin to boost our temperatures so that by Monday, highs will be back into the mid- to upper 20s. This low looks like it will stay well to our north, meaning sunny and warm conditions for at least the first half of next week.
Usual temperature range for this period: Highs, 21 to 30 C; lows, 10 to 16 C.