Heightened thunderstorm risk across Alberta, Saskatchewan and Manitoba
A notable uptick in thunderstorm activity has developed across the Prairie provinces, marking the first “Slight” severe weather risk of the 2025 season. As of Monday, May 12, conditions have evolved quickly, with storms already forming in parts of Southern and Central Alberta, and severe development likely to continue into Tuesday morning across Saskatchewan and Manitoba.
Alberta: Early rain shifting to thunderstorm potential
Heavy rain has been observed throughout the day across Central and Southern Alberta, with thunderstorm activity ramping up through the afternoon. The key risks include strong wind gusts and heavy downpours. Of particular concern is the increased potential for landspout tornadoes, especially in areas around Calgary and just east of the city. These are typically non-supercell tornadoes, often forming in conditions like those currently observed in the region.
Saskatchewan and Manitoba: Main severe threat this evening
The focus for severe weather shifts eastward into Southern and Central Saskatchewan and Southern Manitoba, where isolated supercells may begin forming as early as 5–6 p.m. local time. Forecast models suggest a favourable environment for rotating thunderstorms, particularly during the early evening hours.
Later in the night, between 7–8 p.m., a multicellular storm line is forecast to develop in Southwest Saskatchewan, with the system tracking northeastward across the province and reaching Central Manitoba by early Tuesday morning. Simultaneously, additional isolated storms may form over Southwest Manitoba just before sunrise.
Key hazards: Hail, winds, downpours, and isolated tornado risk
Communities across the affected regions should prepare for:
– Large hail, which may damage vehicles and crops
– Damaging wind gusts, capable of knocking down trees and power lines
– Torrential rainfall, leading to localized flooding
– A low, but non-zero tornado risk, especially in isolated rotating storms
Even though the tornado threat remains limited, one or two brief touchdowns cannot be ruled out given the unstable atmospheric setup.
Stay alert for real-time weather updates, especially if travelling or residing in Southern Alberta, Saskatchewan, or Manitoba tonight and into the early hours of Tuesday, May 13.
