Frigid weekend － possible snowstorm Tuesday

Extreme cold warnings stretch from Manitoba to Labrador (red shading). Those warnings may be extended to southern Ontario and Quebec later today. Snow squall warnings are in effect around the southern Great Lakes.

A frigid polar air mass will engulf eastern Canada and the US over the upcoming weekend. Temperatures will drop into the -20s tonight and not recover much on Saturday. Combined with the cold will be strong northwest winds up to 50km/h in Montreal. Wind-chill values will drop to the low -30s across the region. Extreme cold warnings are in place across a huge area of eastern and central Canada from Manitoba to Labrador. Wind-chill warnings are in effect for most of the northeast US, as well as New England and the Ohio Valley. The extreme cold will be preceded by an arctic cold front today that will produce snow squalls along its path from late today into the overnight hours. A quick 5cm of snow may fall later this evening in Montreal. More snow is forecast along the north shore of Lake Ontario. If your travels take you down Highway 401, expect heavy snow west of Kingston.

Winds will lessen on Sunday, but it will remain cold with early morning lows of -25C (-13F) in Montreal, much colder away from the city. Sunday will be sunny but cold, with a high temperature no better than -15C (5F).

Potential Snowstorm
Looking ahead to next week, temperatures will moderate to near-normal, but there is a chance of snow by Tuesday. Low pressure is forecast to deepen and move from the mid-Mississippi Valley to New England by Wednesday. Depending on the exact track, Montreal may receive in excess of 15cm of snow. Computer forecast models have presented different scenarios ranging from a total miss to rain and temperatures above freezing. I will attempt to fine-tune the forecast over the weekend with updates daily.