Tropical Storm Debby hammers Montreal with historic rainfall

The service roads and ramps off Highway 40 at Cote-Vertu were once again closed this morning due to major flooding. The roads were closed during the evening commute as well, as more heavy rain hit the city. In all between 100-175mm of rain fell in Montreal Friday, an historic amount of rain for one day. (Photo: Oliver Sutton)

A spectacular rainbow has just appeared in the eastern sky here on Ile Perrot after an historic weather day. Tropical Storm Debby dumped two months worth of rain on the region in just a few hours. At my home on Ile Perrot, 175.8mm (6.9 inches) of rain since the pre-dawn hours. This is the most rain I have ever recorded at any location I have lived in in the 48 years I have been observing the weather.

A remarkable 105mm of that total fell between 4pm and 8pm. Normal rainfall for August is just over 94mm. The rainfall today crushed both the daily record of 76.2mm set in 1917 and the monthly record for August set on the 29th back in 1893.

Highway 40 was once again closed Friday evening due to flooding. (Transport Quebec)

The result was as expected, numerous highways and ramps were closed during the morning commute creating gridlock, once again focused around our office at Cote Vertu. Our building flooded again, as it did back in July during Hurricane Beryl. Many drivers were once again stranded as their vehicles became inundated with water. Some of the same roads have been closed by Transport Québec again this evening due to significant water accumulation.

The rain that hit the city late Friday was even heavier, with more highway closures, including the Decarie Expressway.

On top of the heavy rainfall, winds gusted close to 80km/h at Trudeau Airport as the final heavy rain pulled across the region. The result has been widespread power outages to over 120,000 Quebec homes and businesses.

The good news is the rain is now over for Ile Perrot, with the back edge pulling across the city as I write. If the rain has not ended in your location, it will soon. Saturday should be sunny and dry, allowing many to assess the damage and begin the cleanup process. Once again insurance adjusters will be busy.