The weather remains rather quiet and dismal across southern Quebec on Wednesday, with just a couple of weak systems impacting the region. The result has been plenty of cloud cover, some light precipitation at times in the form of drizzle or flurries, and little range in temperature. Temperatures remain well above normal for January, 1C for highs and -3C for lows. This trend will persist for a couple of more days, with changes arriving by the weekend.
An upper level low will move into the Great Lakes on Friday, pushing a frontal boundary towards southern Quebec. Precipitation is forecast to ramp up late Friday and persist into Saturday. A second area of low pressure is forecast to develop along the eastern seaboard, and move northeast towards Maine by Sunday. The combination of these weather systems will deliver precipitation across the region.
At this time, it may be marginally cold enough for wet snow in many parts of southern Quebec and eastern Ontario on Saturday. Precipitation will likely start as a rain/snow mix before changing over to snow in the afternoon and persisting into Saturday evening. It is too early to predict exact amounts, but this looks like a 5 to 15cm snowfall for most, with the lower amounts in and around metro Montreal and higher amount across the mountains.
Much colder air is expected by Sunday, with a return to more normal temperatures next week. Daytime highs will drop into the -7C range with overnight lows in the minus teens. It has been such a mild winter to date, that this will feel downright frigid, especially with gusty northwest winds behind the weekend storm system.
I will post more precise details as the event draws closer, but plan on messy road conditions this weekend.