More snow followed by a much warmer weekend in Montreal

Heavy snow begins to fall during the morning commute in Montreal on Wednesday morning. (ValleyWX)

A rather strong snow squall moved across southern Quebec this morning, impacting the commute in Montreal. The squall put down a quick 5 to 10cm of snow across the region. Near whiteout conditions prevailed, right in the middle of the morning rush. The snow has eased for the moment, but more squalls are possible later this morning and into the afternoon. There is plenty of instability in the atmosphere, even a rumble of thunder is possible during the most intense squalls. Tonight, low pressure will deepen rapidly off the New England coast, pumping abundant moisture back into southern Quebec. A heavy snowfall warning has been posted for the region south of Montreal to the US border and the Townships. This includes Vaudreuil/Dorion and Valleyfield. Steady snow will develop this evening, and taper off Thursday morning. Total storm accumulations for the 24 hours will be in the 15 to 25cm range across southern Quebec by morning. Less snow is forecast to the north of Montreal, with more to the south of the city.

The high temperature will be either side of 0C (32F) through the storm. Overnight low temperatures will be between -6C (21F) and -10C (14F) in Montreal. On Friday, high pressure will begin to nudge into southern Quebec with clearing skies and milder temperatures forecast. By the weekend, we will see the mercury go above freezing, up to 2C (36F) Saturday, and 6C (43F) Sunday.