Winter storm on the way for southern Quebec and Ontario

A poorly timed snow squall arrives along the western tip of the island of Montreal in Senneville late Tuesday afternoon. The squall lasted only 30 minutes, dropping a quick 2-3cm of snow and creating very poor road conditions slowing the evening commute right across the city of Montreal and beyond. (Valley Weather Photo)

Snowfall Warning in effect for Vaudreuil, Ile Perrot, Valleyfield, Cornwall, Ottawa

Special Weather Statement issued for Montreal

Winter Storm Warning for northern New York and Vermont

Wednesday morning is the calm before the storm in Montreal, with bright sunshine and cold temperatures. Widespread weather warnings and special weather statements are posted across all of southern Ontario, Quebec and neighbouring New York and New England in advance of a strong winter storm.

Strengthening low pressure will move from Kansas northeast across New York State on Thursday, followed quickly by a second area of low pressure Thursday evening. The combination of both storm systems will spread snow and freezing rain across southern Ontario today and into Montreal by midnight tonight.

Heavy snow falling just off Highway 40 in Senneville Tuesday afternoon.

After a sunny start to the day in southern Quebec, expect increasing clouds by afternoon. Highs will be chilly, around -5C (23F). The snowfall warning comes into effect this evening and overnight for southern Quebec. At this time it includes all regions from the St. Lawrence River south, but excludes the island of Montreal. Regardless of the warnings, look for snow overnight and Thursday, with the heaviest precipitation falling in the pre-dawn hours. Accumulations at this time are expected in the 10-20cm range for the Island of Montreal, 10-15cm north of the city and 15-25cm from the South Shore, including Vaudreuil and Valleyfield, south to the US border. Overnight lows will be cold, down to -12C (10F), combined with strong northeast winds up to 50km/h. The combination of wind and cold temperatures will allow for widespread blowing snow, especially off island.

Look for poor travel conditions overnight and Thursday morning. The snow may taper off early Thursday afternoon, before strengthening once again in the evening. The storm will finally move east on Friday, followed by frigid air into Saturday morning, with lows in the minus 20s. Temperatures will moderate on Sunday, but with additional snowfall expected.

I know March 1st is next week, in a perfect world the start of meteorological spring. However, keep in mind that historically in Montreal, late February and March usually produce our biggest snowstorms. The weather does look to remain active over the next ten days.