Arctic cold front and snow squalls for Montreal

Snow squalls are expected Thursday across portions of southern Ontario and Quebec. The most intense squalls will occur closer to the Great Lakes in Ontario, and briefly along an arctic boundary expected during the pre-dawn hours in Montreal. Frigid air will pour into the region Thursday afternoon, with windchill values approaching -20C. (OPP Photo)

A strong cold front will slide across the St Lawrence Valley in the pre-dawn hours on Thursday morning, bringing with it some intense but brief snow showers along with plunging temperatures. In Montreal the front should arrive before the morning commute. Roads may become snow covered and icy in southern Quebec.

First off we have milder southwest winds Wednesday evening, that will push the temperature briefly above the freezing point. Already the cold front can be seen on radar over central Ontario. During the overnight, flurries should develop, enhanced locally by moisture from Lake Ontario funneling down the St. Lawrence Valley. The burst of snow arrives in the wee hours, followed by a rapid drop in temperatures for Montreal. 

Thursday's high will be reached in the early morning hours, dropping all day into the minus teens by supper. Adding to the cold, will be gusty northwest winds of 40-60 km/h. Wind chill values will drop into the minus 20s for may locations.

Only a centimetre or two of fresh snow is possible at any one location, but it will be enough to make roads slick, along with reduced visibility at times. Skies will clear out late Thursday, making for frigid overnight lows near -18C (0F) in Montreal and even colder north and west of the city.

Temperatures will moderate during the day on Friday up to -7C (19F), but more cold air and snow is expected by Sunday and into next week as winter takes hold across southern Quebec and eastern Ontario.