Significant ice and snowstorm possible Saturday for Ontario and Quebec

Winter battled back in Montreal this week, with chilly temperatures and plenty of snow showers and squalls. Another round of winter weather is on the way for the upcoming weekend. This weather should not be a surprise to anybody who has lived in Montreal for more than 5 minutes. Late March and April have historically produced some big storms for the city. (Valley Weather Photo)

Special Weather Statement posted for Montreal and Ottawa for a significant late season winter storm this weekend.

High pressure is providing us with a sunny, cool Thursday, after a week of clouds and flurries. Some of the flurries were heavy at times, reducing visibility and glazing roads. With chilly overnight lows at or below freezing, there has been plenty of black ice, resulting in some serious accidents. 

After the sunshine of Thursday, we have a very complex weather scenario setting up for the weekend. Arctic high pressure lies to our north, along with an unseasonably strong Bermuda high to our south. The St. Lawrence Valley will become the battleground between the two airmasses. 

A front will lie just to our south, with low pressure riding along it late Friday and again on Sunday. Heavy precipitation will fall along and to the north of the front. This boundary will separate very warm air, over 21C (70F) surging north into southern New England from sub-zero temperatures, -2C (29F) here in Montreal. Northeast winds will keep surface temperatures below freezing in Montreal into Sunday.

There are lots of details to work out, including the exact location of the front. Some areas in southern Quebec and eastern Ontario can expect heavy snow, followed by a significant amount of freezing rain. Despite the angle of the warming March sun, the April 2023 ice storm taught us the significant damage can still be done from freezing rain in spring.

At this time in excess of 25mm (1 inch) of precipitation is possible for Montréal over the weekend. Some models are showing as much as 50mm. The storm will come at us in all forms from heavy snow Friday and Saturday, to freezing rain and eventually rain on Sunday and Monday.

Plan on difficult travel conditions as well as the potential for tree damage and power outages. Stay tuned for updated forecast and warnings over the next 24 hours. This story will be updated.