A powerful storm that descended on Montreal, downing trees and blocking roads, has left thousands without power and many with damaged homes and cars.

Notre-Dame-de-Grâce and Saint-Henri were among the hardest hit areas, but there were reports of damage on the West Island and in Ahuntsic-Cartierville.

A marquee in the Fairview Mall parking lot was blown over by the wind, lightly injuring three people, trees fell in Ahuntsic and so did metal pole on Henri-Bourassa Boulevard near Highway 13 North.

A tent was toppled at Fairview Mall in Pointe-Claire as strong winds and heavy rain hit Montreal. (Submitted)

Amélie Bertrand of Environment Canada said it's unlikely Montreal was hit by a tornado. There were, however, winds upwards of 110 kilometres an hour.

I've never seen such a wind-force. The [trees] were parallel to the ground. - Wendy Thomas, NDG resident

​Bertrand said the storm was likely a microburst, which she said despite its name is no less intense than a tornado.

A microburst is a column of sinking air that can come down at speeds over 100 kilometres per hour. The damage it leaves behind is recognizable because it often appears to come from one direction.

A tree snapped in half and fell on a Lachine home's roof. (CBC)

Residents in NDG reported streets blocked by large trees that have snapped in two.

Wendy Thomas, who lives in NDG, said the weather changed suddenly around 3:30 p.m. when heavy rains gave way to violent winds that were bending trees in half.

"I've never seen such a wind-force. The [trees] were parallel to the ground," Thomas said.

She heard a loud crack and "raced to the front of the house," to find large branches had fallen onto the street and on cars on the corner of Hampton and Notre-Dame-de-Grâce avenues.

Cars were damaged in Saint-Henri's Saint-Philippe Street. (Derek Marinos/CBC)

Russell Copeman, borough mayor for Côte-des-Neiges–Notre-Dame-de-Grace, said the cleanup has started in the borough and that it could last a few days.

In a news conference with deputy director of the Montreal fire department Richard Liebmann, Copeman said Liebmann's "presence here would seem to indicate that this neighbourhood was one of the worse affected on the island of Montreal."

"I've never seen an electrical pole that sheered off at six-feet in this community, so it's a major incident," the mayor said.

Copeman added that crews were focused on making sure everyone was OK, and on clearing Monkland Avenue and making it accessible.

Liebmann said all the power in the area delineated by Coronation and Girouard streets between Sherbrooke Street and Côte Saint Luc Road had been turned off for safety reasons.

"Always consider downed wires as live wires," he said. "If you see a line down, don't go anywhere near it, don't hesitate to call 911 and we'll come check it out if we're not already aware of it."

Though the southwest of the city is the most damaged, there was some reported to the north in Ahuntsic.

Though much of the storms damage occurred in Montreal's southwest, there were some reports of snapped trees to the north, in the Ahuntsic-Cartierville borough, on Saint-Denis Street between Henri-Bourrassa Boulevard and Prieur Street. (Daniel Boily/Radio-Canada)

Serge Abergel, spokesperson for Hydro-Québec, said 63,000 customers are without power in Montreal, and 115,000 are without power across the province.

As of 10 p.m. Tuesday, its website said there were still 48,700 outages in the city and 73,000 across Quebec.

"It's knocked down wires, causing power outages in certain areas," Abergel said.

Hydro-Québec later updated its website, saying the main regions — other than Montreal — affected by outages are the Laurentions and the Richelieu regions.

A metal pole fell down onto Henri-Bourassa Boulevard at the height of Highway 13 North. (Submitted)

"The storm front is currently crossing the province from west to east," the statement said, adding that 212 of its crews were working on restoring power in those areas.

"Strong winds are expected in its wake, which will likely cause more outages."

Earlier Tuesday, the weather agency issued a severe thunderstorm watch for Montreal and some of the surrounding areas, including places in the Lanaudière region, Laurentians and Eastern Townships.

Clenaup crews were already at work cleaning fallen trees in Saint-Henri. (Derek Marinos/CBC)

Work crews were already in the streets of Saint-Henri, clearing trees off the roads.

The weather agency is advising people to take cover immediately if threatening weather approaches, adding that "severe thunderstorms can produce tornadoes."

Le marché Atwater après la tempête 😲 <a href="https://t.co/0mJivNlGdE">pic.twitter.com/0mJivNlGdE</a> —@le1518

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