The shelf cloud as seen from the Bonsecours market area in Old Montreal. ((Submitted by Denis Sobolj))

Environment Canada says funnel clouds that rolled through the greater Montreal region Monday afternoon were in fact tornadoes.


The funnel was visible in Kirkland, on Montreal's West Island. ((Submitted by Karim Jeraj))

The federal weather bureau said two tornadoes were registered in the island region: one in Sainte-Anne-de-Bellevue, on Montreal's West Island, at 3:30 p.m., and one in Mascouche, east of the city, just before 5 p.m.

Both tornadoes were rated as F0, the lowest intensity on the Fujita scale. Winds up to 90 kilometres per hour were recorded in both areas, said Environment Canada meteorologist René Héroux.

The storm knocked out power in some areas of Montreal, and blew branches off trees.

The large, low-lying black mass seen in Montreal's sky was a shelf cloud, Héroux added.

Shelf clouds are created when a squall line encounters unstable air pockets and very strong winds.

The weather system has moved on and temperatures should be cool until the weekend, Héroux said.

Quebec gets an average of six F0 tornadoes per year.


  • An earlier version of this story reported the tornado was registered in Ste-Anne-de-Beaupré. In fact, it was registered in Sainte-Anne-de-Bellevue.
    Jun 29, 2010 2:22 PM ET