|Flooding after Monday's severe thunderstorm under Cote-de-Liesse at Hickmore. Firefighters opened the manhole cover to release the flood waters. (CTV News)|
|Flood waters gather in the parking lot along the Trans Canada Highway at Cote-Vertu on Monday, July 31. (Valley Weather)|
Severe Thunderstorm Produces Flooding
On Monday afternoon, a strong isolated thunderstorm cell moved from Laval across north central Montreal towards Trudeau Airport between 4 and 5pm. The storm brought torrential rain, with between 33mm and 37mm falling in less than one hour in Saint Laurent and Dorval. The result was flooding of several basements and highways. Our parking garage and ramp here at The Suburban flooded rapidly from the torrential rain. Strong wind gusts in excess of 85km/h brought down several trees. Lightning and wind knocked out power to over 17,000 Hydro Quebec customers in metro Montreal. The thunderstorm also produced pea size hail. The storm rapidly dissipated as it swept southeast across the Island of Montreal. The isolated nature of this particular storm produced the heavy rain and flooding in a narrow swath through the city. I measured no rain at all on L'Ile Perrot, just 20 kilomteres to the southwest of Trudeau Airport.