Strong thunderstorms produce flash flooding in parts of Montreal and South Shore

Flash flooding in Pierrefonds on Saturday afternoon. Strong thunderstorms have been moving over the same area for several hours now producing torrential rain, in some cases in excess of 100mm from Laval southeast across Montreal and onto the South Shore. (Photo: Luka Korda via West Island Community Page)

Severe Thunderstorm watches and warnings for southwestern Quebec including metro Montreal through this evening.

Strong thunderstorms have been moving southeast across portions of Laval, through Pierrefonds, Dorval and central portions of the Island of Montreal and onto the South Shore Saturday afternoon, producing widespread lightning and torrential rainfall. Radar estimates and reports form local weather stations are indicating anywhere from 30mm to as much as 100mm has fallen in the last several hours.

At Trudeau Airport, 32.1mm has fallen in the last few hours, with nothing at my weather station on Ile Perrot.

The storms are training over the same region. Flooding has been reported in Pierrefonds and well as on the South Shore in La Prairie and Saint Constant. Several roads have been inundated, while others have significant water accumulations.

Radar is showing more storms developing over the lower Laurentians moving into the Montreal region. Remain vigilant this evening especially after dark. Do not attempt to cross flooded roadways.

Hydro-Quebec is reporting outages to just over 9000 customers at 5:40PM

The showers and storms should weaken after sunset, but more are expected on Sunday. The culprit is strong low pressure over Atlantic Canada sending disturbances in the atmosphere pinwheeling into our region. Conditions should improve Sunday night. 

Radar shows a plume of thunderstorms extending from Laval onto the South Shore. They have been dumping torrential rainfall over the same sections of the city, with 30mm to as much as 100mm falling just in the last few hours.