Extended winter storm for southern Quebec

Deepening low pressure is forecast to move across New England late Thursday and Friday, with 15 to 25cm of snow possible across southern Quebec. (AccuWeather.com)

Special Weather Statement in effect for Montreal.
Winter Storm Watch posted for Sherbrooke and the Townships.
Winter Storm Warning in effect for northern New York and Vermont.

Much colder air settled across the St. Lawrence Valley on Thursday after several days of above normal temperatures. The high on Thursday was -2C here on L'Ile Perrot, reached at midnight. The mercury has been falling all day to our current temperature of -9.6C. Temperatures should level off  by midnight as clouds thicken up in advance of our next winter storm.

Overnight an elongated warm front will lift northward towards southern Ontario and Quebec. Precipitation should begin overspreading the region by daybreak from the US border into Montreal. Snow will be steady during the morning hours with 5 to 10cm expected by late afternoon in Montreal. The snow will likely impact both the morning and evening commute in the region. Spotty freezing rain may mix in along the US border, but it should be light.

Strengthening low pressure will move from the southern US into New England on Friday with additional snowfall expected. Montreal will get a brief break in precipitation Thursday evening, before more snow, heavy at times arrives overnight into Friday morning. The second batch of snow will be intense at times, with an additional 10-15cm possible for Montreal. Storm totals may exceed 30cm over the Eastern Townships, and 40cm over northern New York and Vermont. Lesser amounts of 10-20cm are expected across eastern Ontario.

As the low pressure deepens and moves northeast into Atlantic Canada, wind speeds will increase across southern Quebec, up to 50km/h at times. Gusty winds will persist into Friday, with areas of blowing snow possible. Temperatures throughout this storm will remain below freezing in Montreal. The special weather statement currently in effect for Montreal may be upgraded to a weather warning by Thursday morning.