Southern Quebec is bracing for a cold snap that could cause temperatures to drop by more than 15C below normal for some regions.

By Sunday afternoon, Environment Canada said the island of Montreal could see winds of up to 90 kilometres per hour.

The situation should improve by Monday when temperatures plummet.

The Quebec City region should expect to see up to 30 centimetres of snow and strong winds as an Alberta clipper – a fast-moving low-pressure system traveling through mid-central Canada – swarms the region.

Environment Canada warns the Abitibi region could reach a frigid –40C Sunday afternoon and night.

Montrealers will also have to bundle up this week, as temperatures drop to approximately –30C with wind chill.

The cold snap is expected to last until the weekend.

Whiteout stalls drivers

The snow squall and wind warnings Environment Canada had issued earlier Sunday have now ended.

Many drivers were affected by poor visibility on the roads for a large part of the day.

Ontario police closed off a large section of Highway 417 from the east end of Ottawa to the Quebec border due to whiteout conditions.

Strong winds may still affect driving conditions. Wind speeds could reach as high as 90 kilometres per hour along the Saint-Lawrence River.

Visibility was changing dramatically, as documented by this series of pictures taken within an hour. (Erin Anderson)

500 clients without power

Shortly before 3 p.m., 500 homes and businesses were still without power on the island of Montreal.

Hydro-Québec said a thunderstorm caused some of the outages on Sunday morning but ongoing winter precipitation and high winds have also impacted the system.

Blowing debris

Wind gusts of up to 65 kilometres per hour were the cause of several issues in downtown Montreal.

A crane on the corner of Stanley Street and René Levesque Boulevard broke several windows of a building around 8:15 a.m.

Francis Leduc, chief of operations for the Montreal fire department, said the 150-metre crane had to be retracted.

"We right away secured the area because we didn't want any accidents to happen," he said. "Nobody was injured."

He said glass debris from broken windows could be found on Peel Street, which runs parallel to Stanley. Leduc estimates that the building is about 40-storeys tall.

Nearby streets reopened around 11:30 a.m.