As we quickly approach the final days of summer, the battle between seasons will be evident over parts of the Prairies this week. A large mesoscale cyclone will spill heavy rain over Alberta and Saskatchewan, while parts of Manitoba see temperatures soar into the 30s, including the city of Winnipeg, which will be about 10°C warmer than normal.
Visit our Complete Guide to Fall 2024 for an in-depth look at the Fall Forecast, tips to plan for it and much more!
There is lower confidence in exact rainfall totals and locations, but it looks as though 30-50+ mm will fall along the Alberta and Saskatchewan border.
This will be beneficial for northern sections of Saskatchewan still dealing with ongoing wildfires, but also heightens the threat for localized flooding in some of the harder-hit areas. Be sure to stay alert to the changing conditions and any warnings that are issued in your area.
Wednesday through Friday:
Some rain will begin along the foothills Wednesday evening, but the heaviest rain and impacts will be widely felt through Thursday. That’s as a slow moving low pressure system pushes north of the U.S. border, spilling heavy rain at times during Thursday and Friday.
The rainfall intensity will increase in several rounds.
By Thursday morning, heavy rain will spread across southern Alberta, including the city of Calgary.
Heavy rain, and possibly severe thunderstorms, will take aim at southern Saskatchewan Thursday afternoon, lifting north into Saskatoon by the evening hours.
In addition to heavy rain, strong winds and large hail are the main risks with any storms that develop.
While there’s still some uncertainty with exact rainfall totals and locations, a widespread 10-20 mm of rain is likely, with heavier amounts exceeding 30-50+ mm possible along the Alberta and Saskatchewan border. Higher rainfall totals are possible in embedded thunderstorms.
Summer vs. Fall: The temperatures say it all
A large temperature contrast will span the Prairies, as well, essentially bringing two different seasons to the region.
Much of Alberta will get an early taste of fall, remaining seasonably cool for most of this week. Calgary will sit about 7°C cooler than normal. Meanwhile, parts of Manitoba will certainly enjoy a late blast of summer heat as temperatures soar close to the 30-degree mark.
For more on exactly what to expect, be sure to check out our official 2024 Fall Forecast.