What to expect as remnants of tropical storm Debby move across Canada

Remnants of tropical storm Debby were soaking a large swath of Eastern Canada Friday, expected to bring as much as 120 millimetres of rain in some areas as they merged with another low pressure system over the Great Lakes.

The storm system was moving across southern Ontario and Quebec, prompting Environment Canada to issue alerts and warnings for communities between Cornwall, Ont., and Quebec City about the risk of flash flooding.

• IN PICTURES: Tropical Storm Debby leaves path of destruction

By 10 a.m., between 60 and 80 millimetres had already fallen in Montreal with more expected later in the day.

"We are still expecting at least 40 (more millimetres), which could bring the total to over 100 millimetres of rain for the day," said Environment Canada meteorologist Michele Fleury.

Post-tropical Cyclone Debby is seen in an RGB image from the National Oceanic and Atmospheric Administration, captured at approximately 5:30 a.m. on Friday, Aug. 9, 2024.

Forecasts show the Montreal area receiving 80 to 120 millimetres by the end of the day -- with some locations in southwestern Quebec expected to receive as much as 140 millimetres.

The rain was expected to end in Quebec Friday night, with a few scattered showers remaining into Saturday, Fleury said.

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The heavy rain forced the closure of some attractions in the province, including Montreal's La Ronde amusement park and the Granby Zoo, east of Montreal. The opening events scheduled for the International de montgolfieres, a hot-air balloon festival in St-Jean-sur-Richelieu, southeast of Montreal, were postponed until Monday.

Montreal Pride announced it was postponing outdoor activities including community day in the Village and the Soiree 100 per cent Drag at Montreal's Olympic Park's esplanade, now taking place Saturday. "Tropical storm Debby won't stop us from celebrating our pride!" organizers wrote.

• Rainfall warnings issued in Eastern Ontario

One Montreal non-profit day shelter, Resilience Montreal, reported flooding at their offices. The organization's founder, Nakuset, took to social media to ask for help. The centre serves 1,000 meals a day.

"If you can come and help us, please do so," she wrote on the X social media platform.

Quebec's Transport Department warned of some flooding on highways and temporary road closures due to the torrential rain. Most of the incidents of localized flooding were in and around north-central Montreal. Provincial police said they were in touch with various partners regarding weather conditions, but did not report any major traffic accidents linked to the inclement weather.

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Environment Canada has warned that minor landslides are possible.

Ottawa was also forecast to be soaked, with 50 to 100 millimetres of rainfall expected through the day. In Toronto, between 25 and 50 millimetres of rain is expected to fall through the morning and early afternoon.

The remnants of Debby are expected to reach New Brunswick by evening and dump up to 40 millimetres of rain through Saturday morning.