|A blizzard warning is in effect for metro Montreal as strong low pressure moves from the lower Great Lakes into New York.|
A rarely-issued blizzard warning has been posted or tonight for southern Quebec, primarily the St. Lawrence Valley including Montreal. Environment Canada defines a blizzard as four or more hours of heavy falling or blowing snow, 40km/h winds or higher, cold temperatures of -10C (14F) or lower and visibility of less than 400 metres (0.4km). I can't recall a blizzard warning being issued for Montreal in recent years, and that includes some substantial storms. I don't think this system will be epic, but it will certainly be challenging for anybody traveling overnight from Quebec City into southern Ontario.
March certainly came in like a lion, with wild weather over the last 24 hours. After several hours of freezing rain Monday morning, a powerful arctic front raced through the city last night. The front was accompanied by thunder and lightning, as well as brief, heavy snow and 80km/h winds in Montreal. In its wake, we have a very cold but calm morning, with a temperature of -15C (5F).
Today will be fair, with increasing clouds and a high near -10C (14F). Tonight, snow will develop, becoming heavy after midnight, along with increasing northeast winds up to 70km/h and cold temperatures near -10C. Widespread blowing snow will reduce visibility to under 0.5km at times. Snow accumulations in the city should range from 10-20cm overnight, with storm totals near 30cm by the time precipitation ends early Wednesday afternoon. Low pressure will move from the Ohio Valley just south of Montreal and into Maine Wednesday. Winter storm warnings are also in effect down the St. Lawrence River towards Kingston and west into Toronto. Travel along the 401 corridor will be very difficult starting today through early Wednesday. Heavy snow is also expected north of Montreal. More than 30cm is forecast from the Ottawa Valley across the Laurentians.