Coldest air of the season this weekend - snow?

The coldest air of the season to date will pour into southern Quebec and Ontario this weekend.

Snow this weekend? There are hints of the four letter word creeping into the forecast. Don't panic just yet. Cold air will pour into Ontario and Quebec behind a cold front late Friday. Temperatures will fall to near 0C (32F) by Saturday morning, and even colder -2C (28F) by Sunday here in Montreal. It will be much colder north of the city in the Laurentians, dropping to as cold as -10C (14F). I expect a widespread frost and freeze bringing the growing season or what is left of it to an end.

Snow
As far as any snowfall goes, there will be moisture available behind the front Friday, but it will be fairly limited in the valleys with perhaps a flake or two in Montreal. However, if you are travelling northwest of Montreal towards Val-d'or, where it is snowing this morning, or south across the Adirondacks of New York or Green Mountains of Vermont, there could be quite a bit more. Computer models are hinting at perhaps 5-10cm (2-4 inches) of new snow by Sunday morning across areas above 1500 feet. Even 15cm (6 inches) is forecast at Jay Peak. If you are taking Interstate 89 or 87 south, you may encounter snowfall Saturday night. Be aware of this.

It will turn warmer next week after the brief cold spell. However, you should be thinking about winter tires. It looks like there could be several opportunities for an early season snow in November over southern Quebec. Just a heads up.