Environment Canada Issues Heavy Rain Warnings Across Quebec and Ontario

Heavy moisture-laden air has triggered widespread severe weather alerts across the region. Environment Canada issued weather warnings for an extensive stretch of Quebec running from Saint-Sauveur to Saguenay, encompassing Trois-Rivières, Saint-Michel-des-Saints, Mont-Tremblant, Parent, and La Tuque. According to the federal agency’s written alert, between 50 and 80 millimetres of rain are expected to accumulate by Thursday morning, while localized thunderstorms could push totals past 100 millimetres in hardest-hit areas.

Torrential Downpours and Urban Flooding Risks

The storms have already delivered significant volumes of precipitation. In Montérégie, local accumulations reached nearly 60 millimetres, causing reduced visibility for drivers and leaving roads on the southern crown of the metropolitan area difficult to access. Environment Canada warned that pooled water on roadways could wash out vehicles, trigger landslides, or compromise infrastructure.

Do not drive on flooded roads. Environment Canada

Temperature highs across the affected zones vary. The greater metropolis, Saint-Jérôme, Lanaudière, and the Laurentides expect 15 to 20 millimetres from afternoon showers, with temperatures reaching 20 to 22 °C and humidex values hitting 27 to 29. Meanwhile, Estrie, Beauce, Mauricie, and Quebec City face similar forecasts with slightly warmer temperatures between 23 and 26 °C and humidex readings up to 32.

Tornado Confirmations in Saint-Donat and Harrington

The current deluge follows severe convective activity earlier in the week that spawned confirmed tornadoes in the Laurentides and Lanaudière regions. Researchers from the Northern Tornadoes Project (NTP), affiliated with Western University in Ontario, examined satellite and drone imagery to confirm a second tornado struck Saint-Donat in Lanaudière on Tuesday.

That event occurred around 18:40, roughly an hour after an initial EF1 tornado swept through Harrington with maximum winds reaching 175 km/h. The Saint-Donat twister was classified as weaker at EF0, packing winds up to 115 km/h and leaving damage concentrated over a short distance of less than a kilometre near Lake Beauchamp, though no injuries were reported.

Ottawa and Outaouais Recovery Following July Storms

Across the provincial border, the Outaouais and Eastern Ontario are also bracing for 50 to 100 millimetres of rain through Wednesday morning. These incoming storms compound recovery efforts in Ottawa, which continues to address damage from a severe storm on July 1. According to Radio Canada’s reporting on Environnement Canada data, 118 millimetres fell in four hours at the Ottawa international airport during Canada Day festivities, triggering widespread flooding and downed trees.

Total precipitation in Ottawa for the month has already reached 222.3 millimetres, far exceeding the three-decade July average of 88.5 millimetres. With rain forecast to persist across much of Quebec into Thursday, local authorities urge residents to maintain caution near waterways and avoid flooded infrastructure.