Update 11:00AM, Thursday, February 13: The arctic cold front has passed though Ottawa, and the temperature has fallen quickly from -3C (27F) at 9am to -9C (16F) at 11am. Extreme cold warnings are now in effect for all of southern and eastern Ontario for windchill readings as cold as -35C (-30F). The front will move through Montreal early this afternoon, with rapidly dropping temperatures for the rest of the day. Roads may become slick as the temperature falls.
8:15 Post: So far the snow has been rather light and unimpressive in Montreal. Radar is showing very light, scattered snow showers across the region. Perhaps Environment Canada was correct on the lower amounts for Montreal. We will see how the day plays out. For now, roads are in good shape and precipitation is light with less than 1cm accumulation so far. The forecast is for 2-4cm for the city and 5 to 10cm south of Montreal to the US border.
Previous Post: Another shot of snow is on the way for southern Quebec, adding to the 45 to 55cm that has fallen since last Thursday. Low pressure over the Ohio Valley will rapidly move across central New England on Thursday and out into the Atlantic. The storm will be quickly followed by a surge of arctic air late in the day.
Snow will spread into Montreal before the morning commute Thursday, and taper off to flurries in the afternoon. Environment Canada is aiming low for Montreal, calling for 2-4cm total accumulation. I feel it will be more in the order of 5 to 10cm in southern Quebec and eastern Ontario, with up to 15cm along the US border. The snow may be enhanced briefly during the morning hours as an arctic cold front cuts across the region. Winds will increase out of the northwest up to 40km/h and temperatures will plummet in the afternoon and evening hours. The high Thursday will be reached early in the morning in Montreal, at -1C (30F). The temperature will fall to around -20C (-4F) by Friday morning across metro Montreal. Most of central Quebec is under extreme cold warnings, for windchill readings near -40C. Montreal can expect windchill values well into the -20s Thursday night.
Friday will be blustery and cold, with daytime highs struggling to reach -12C (10F). The weekend will be milder once again, but unsettled with plenty of clouds and flurries around. As we head into next week, another winter storm may impact Montreal by Tuesday with measurable snow.