Christmas storm to bring rain and wind to southern Quebec

Woodland Avenue in Verdun looking a little festive in the snow this past Sunday. The thin layer of snow in Montreal will melt away on Thursday as temperatures soar to 10C (50F). (ValleyWeather Photo)

Winter is here, officially arriving on Monday morning at 5:02. The good news is that the days will now slowly get longer. To celebrate winters arrival, we have a little light snow falling early Tuesday morning, but it remains very mild, near the freezing point in Montreal. December has certainly fooled many forecasters, while I personally expected mild weather, I also expected plenty of snow to go along with it. It just has not developed that way. The majority of systems have delivered rainy, mild weather or missed us completely to the south or west. So as we head towards Christmas, we have less than a 1cm of snow on the ground in Montreal, with only 10.8cm falling for the entire month of December. Toronto has actually had more snow this month.

Another warm storm is upon us, with heavy rain and strong winds expected beginning Thursday afternoon. An elongated arctic front will push east across Ontario on Thursday, with the front becoming the focus for deep Gulf of Mexico moisture. Heavy rain is forecast Thursday afternoon into Friday morning, with as much as 40mm possible. Low pressure is forecast to develop along the front and move north into eastern Ontario enhancing the rainfall. The low will also allow a surge of mild air in advance of the system, with high temperatures possibly above 10C (50F) in southern Quebec from Thursday into Christmas Day. Accompanying the rain will be very strong gusty southeast winds. Winds may approach 80km/h in some portions of our forecast region. Minor flooding is also possible, especially in any regions that do have snowpack.

Cold air will surge in behind the Christmas Day storm across southern Quebec, changing the rain to snow. Only minor snow accumulations are expected in Montreal. (AccuWeather.com)

As the front pulls across southern Quebec on Friday, very cold air will rush in behind it. Any leftover precipitation will changeover to a period of snow or flurries on strong northwest winds. The rain will change to snow from west to east across Ontario then Quebec. Temperatures will tumble from well-above the freezing point to -10C (14F) by Saturday morning. Any standing water will freeze over, so keep this in mind if you venture out on Friday.

There are still many details to fine tune over the next 48 hours, but I don't see this anything other than a very mild forecast for Montreal. Now quite normal for Montreal, this will be our third consecutive very green holiday season.