The first part of this forecast period is going to feel fairly fall-like, as our weather is dominated by a large and strong upper low. This low has sat over Hudson Bay for the last week or so and has been responsible for our cool weather of late. The weather models show this low will finally start breaking down and moving off to the East. Before it does, it is expected to drop southward, bringing cool conditions along with unsettled weather.
As this upper low drops southward it will bring with it plenty of cool air, especially in the upper atmosphere. This means daytime highs will struggle on most days to reach 20 C. Most days will see a mix of sun and cloud, with clouds increasing during the day as daytime heating sets off cloud formation. Along with the clouds there will be widely scattered showers and even the odd thundershower.
The upper low looks to finally move out of the region by Saturday. We’ll continue to be under a northwesterly flow over the weekend, but with a warmer upper atmosphere and surface high pressure we should see mainly sunny skies on both Saturday and Sunday. The sunshine should help to boost temperatures back into the mid-20s.
The sunny and warm conditions should continue into the first part of next week. By mid-week the weather models show a building ridge of high pressure to our southwest. This will begin to switch the airflow across our region to more southwesterly, meaning an increase in humidity along with the chance of thunderstorms — in other words, typical summer-like weather.
Usual temperature range for this period: Highs, 20 to 30 C; lows, 8 to 15 C.