This extreme phenomenon would have unsuspected consequences in Quebec

Snow squalls

When the cold circulates above the Great Lakes and the atmospheric conditions are favorable, an extreme phenomenon risks occurring: coastal snow squalls. Heavy accumulations can bury an area within a few hours. It is precisely this scenario that awaits certain sectors by Wednesday when 10 to 50 cm could fall.

Cloudy overflow

Part of this instability should spill over into Quebec overnight from Monday to Tuesday. While certain sectors of Ontario could receive heavy accumulations of snow, the south of La Belle Province would mainly suffer from overflowing clouds, dotted with a few flakes in places. Moreover, a beneficial effect would be felt. Since the polar vortex is acting up and the mercury is taking a dizzying plunge during the night, the presence of these clouds should slow down the descent.

Absorbing clouds

The clouds would be beneficial given the extreme cold currently reigning in Quebec. In the south of the province, the night from Monday to Tuesday was expected to be particularly frosty, but a cloud cover will help retain some of the heat by returning it to the surface. Conversely, a perfectly clear sky lets it escape towards the upper atmosphere. This is what is expected in Abitibi, where the mercury could reach -40°C in places.

freezing night

Montreal has not experienced a minimum of -20°C since February 2023. According to models, the mercury could reach this threshold and even plunge even lower. Moreover, due to this overflow of clouds caused by the instability above the Great Lakes, everything is not yet decided for the metropolis.

With the collaboration of Kevin Cloutier, meteorologist.