Snowfall Warning posted for southern Quebec

A few centimetres of  fluffy light snow overnight made for a slick Wednesday morning commute in Montreal. Like a broken record this month to date, there were numerous accidents reported. Roads will be in even worse shape for the Wednesday evening drive home, as moderate snow is forecast for the Montreal region. (Valley Weather)

 An Alberta Clipper storm system will slide across the Great Lakes on Wednesday and down the St. Lawrence Valley. An area of steady snow is currently approaching the Montreal region, with as much as 10cm expected over the next few hours. The snow will become lighter overnight and taper off on Thursday, with another 5-10cm possible.

Widespread snowfall warnings are in effect from southern Ontario into southern Quebec. On the backside of the low pressure, winds will increase sharply on Thursday, gusting up to 60km/h. The temperature will fall as well from early morning highs near the freezing point to -10C (14F) by afternoon. The gusty winds will produce areas of blowing snow, along with significant windchill values, into the minus 20s.

Travel was already difficult on Wednesday morning, with numerous accidents reported in the region. One accident closed Highway 50 near Mirabel in both directions. Roads will continue to be in poor shape during the Wednesday afternoon commute in Montreal, with moderate snow and icy road surfaces. In eastern Ontario, moderate snow resulted in most regions canceling school bus service.

Conditions should improve Thursday afternoon, but the weather will remain breezy and cold.

Throwback cold and snowy winter underway in Montreal

Winter has started early in Montreal this year, with below normal temperatures and frequent snowfalls. While accumulations have been light for the most part, the frequency of the snow is keeping roads slick and icy and road crews busy. (Valley Weather Photo)

It has been years since Montreal had below normal temperatures to start December, but that is what we have in 2025. The temperatures on Monday morning was a chilly -18C (0F), this after Friday mornings low of -19C (-2F) on Ile Perrot. To date 8.2cm of snow has fallen at Trudeau Airport, on top of the 28cm that fell in November. The monthly mean for November was 1.1C below normal, the first time in months we have had a below normal average. 

The cold temperatures combined with Sunday's snowfall left roads icy during the Monday morning commute. Once again, there have been a rash of serious accidents across the Montreal region, as drivers fail to respond to the road conditions. Reduce your speed, clean your vehicle off and make certain you have snow tires on, the law since December 1st here in Quebec.

The long-term average high/low for early December in Montreal, is -1C/-9C respectively.  The high in Montreal on Monday will only be -13C (9F), with windchill values in the minus 20s. We will see a slight moderation in temperatures midweek as a series of clipper systems moves from western Canada across the Great Lakes and just south of Montreal.

Two Alberta Clippers over the weekend managed to accumulate 5-10cm of snow across most parts of southern Quebec. More clipper type systems are expected this week, along with continued cold temperatures. (Valley Weather Photo)

The first in the series of low pressure systems will arrive late Tuesday, with a few light snow showers possible for southern Quebec. A stronger system arrives on Wednesday, with a period of steadier snow, perhaps 5-10cm, followed by another surge of cold air. The high on Tuesday and Wednesday will be between -1C and -3C (27F to 30F), before dropping back into the -10C range by Friday.

More snow is possible to end the week as yet another area of low pressure approaches from the Great Lakes. The good news so far is that most of these storm systems are expected to be on the weaker side.

One thing is certain, expect below normal temperatures to persist through the holidays.

Arctic cold front and snow squalls for Montreal

Snow squalls are expected Thursday across portions of southern Ontario and Quebec. The most intense squalls will occur closer to the Great Lakes in Ontario, and briefly along an arctic boundary expected during the pre-dawn hours in Montreal. Frigid air will pour into the region Thursday afternoon, with windchill values approaching -20C. (OPP Photo)

A strong cold front will slide across the St Lawrence Valley in the pre-dawn hours on Thursday morning, bringing with it some intense but brief snow showers along with plunging temperatures. In Montreal the front should arrive before the morning commute. Roads may become snow covered and icy in southern Quebec.

First off we have milder southwest winds Wednesday evening, that will push the temperature briefly above the freezing point. Already the cold front can be seen on radar over central Ontario. During the overnight, flurries should develop, enhanced locally by moisture from Lake Ontario funneling down the St. Lawrence Valley. The burst of snow arrives in the wee hours, followed by a rapid drop in temperatures for Montreal. 

Thursday's high will be reached in the early morning hours, dropping all day into the minus teens by supper. Adding to the cold, will be gusty northwest winds of 40-60 km/h. Wind chill values will drop into the minus 20s for may locations.

Only a centimetre or two of fresh snow is possible at any one location, but it will be enough to make roads slick, along with reduced visibility at times. Skies will clear out late Thursday, making for frigid overnight lows near -18C (0F) in Montreal and even colder north and west of the city.

Temperatures will moderate during the day on Friday up to -7C (19F), but more cold air and snow is expected by Sunday and into next week as winter takes hold across southern Quebec and eastern Ontario.

Cold, snowy week ahead - Meteorological Winter has arrived in Montreal

A strong cold front has ushered out the foggy damp weather from last week in Montreal and announced the arrival of Meteorological Winter. A cold, snowy pattern will become established for at least the upcoming week if not longer. (Valley Weather)

December 1st in Montreal, the unofficial start of the Holiday Season, the winter tire deadline and the official start to Meteorological Winter. The equinox will not occur until December 21st, but trust me winter is here.

On Sunday a few centimetres of wet snow fell in Montreal, which promptly froze overnight as a cold front swept across the region. Temperatures fell from above freezing around midnight, to current readings in the -6C (21F) range in Montreal. Gusty northwest winds of up to 50km/h have dropped wind chill values into the minus teens for the first time this season. High pressure will briefly build in today, but it will remain cold with steady temperatures. Sunday's snow brought an end to what was a wintry month in the city, with 28cm of snow falling.

Heavy lake effect snow over the last week resulted in dangerous driving conditions along with hundreds of accidents for many parts of southern and eastern Ontario. More snow is expected this week as a strong arctic boundary sweeps across Ontario and Quebec by Thursday. (Ontario Storm Reports)

Overnight into Tuesday, a deepening winter storm will move from the Ohio Valley across southern New England and off the eastern seaboard. Montreal will remain on the northern edge of the heaviest precipitation, with light snow expected for the city. Gusty northeast winds will make it feel very cold, with daytime highs around -4C (25F). At this time, only a couple of centimetres are expected for Montreal, with less to the north of the city and between 5 and 10cm along the US border. 

On Wednesday and arctic boundary will be approaching the region from Ontario. This front will deliver a round of snow flurries and squalls late Wednesday into Thursday morning, along with a reenforcing shot of cold air. Temperatures will drop into the minus teens for lows and only to -8C (18F) for a high on Thursday.

More snowy weather along with cold temperatures are expected for next weekend as winter takes hold in Montreal. While no major storms are on the horizon at this time, a bunch of smaller events will still create slick driving conditions at times. Winter is here! Give yourself extra time, clean off your car and bring patience with you when you leave your home and make certain you have winter tires on. Stay safe.

Environment and Climate Change Canada announces new weather warning guidelines

The devastating and historic 1998 Ice Storm here in Montreal would be an example of a Red Weather Warning under the new ECCC guidelines. (Hydro-Quebec)

On a day when a strong Great Lakes storm, a November Witch, is unleashing heavy lake effect snow, strong winds and towering waves, Environment and Climate Change Canada (ECCC) announced it has established a new way of warning Canadiens about severe weather.

All weather warnings will now be accompanied by a colour code, Yellow, Orange or Red. Each level will describe the severity of the anticipated weather event as well as its impact on the general public. There is also a level of forecaster confidence attached to each colour as described in the public warning when issued by ECCC.

“We continue to experience more frequent and extreme weather in Canada, which makes it more important than ever for Canadians to have access to clear, accurate, and easy-to-understand weather alerts. By improving how severe weather is reported, we are helping Canadians better understand and prepare for potential impacts, so they can make informed decisions about how and when to protect themselves, their loved ones, and their property.”
according to The Honourable Julie Dabrusin, Minister of Environment and Climate Change.

A Yellow Warning is the most common type. Currently there are yellow warnings in effect for parts of central Ontario and Quebec for snow and blowing snow. Yellow warnings are used to describe severe weather events that are moderate in nature, localized and for a short-term. They would include most regular heavy snowfalls that occur here in the Montreal area, such as the 15-25cm events.

An Orange Warning will be less common and associated with a weather event that can be much more damaging or disruptive. They would include blizzards and severe thunderstorms or heavy lake effect snow events. Major widespread damage would be possible, along with disruptions lasting a few days. Orange warnings are in effect today for parts of the snow belt regions surrounding the Great Lakes.

Red Warnings will be rare. They will involve an elevated level in forecaster confidence for the event to produce life-threatening, extensive, prolonged and widespread damage. An example of this would be the 1998 Eastern Canadian Ice Storm or the Atmospheric River flooding in British Columbia in 2021.

Personally, I think any program that will provide more details to the general public regarding incoming severe weather, will be more than welcome.

The new guidelines came into effect on Wednesday, November 26, and is already being implemented for current forecasts.

Mild weather week followed by a significant pattern change for southern Quebec

Milder weather this past week has melted away most of the 25cm of snow that has fallen in Montreal this November. Much colder air along with more significant snow is possible by the first week of December. (Valley Weather)

We have a mild Monday morning in Montreal, but not without a few icy spots after Sunday's wet snow. On Sunday, another 1 to 2cm of snow fell on the city, bringing the monthly total to over 25cm. Last November we had none. The trend for snowy weather will return, but not until the first few days of December. Until then, we can expect a very mild week, with periods of light rain at times through Thursday. Skies will be mostly cloudy, but temperatures will be mild, with daytime highs between 3C and 7C (38F-45F) and overnight lows near the freezing point.

On Thursday, a strong cold front will will move across Ontario and Quebec, introducing the pattern change I mentioned in the title. Thursday will be very windy. Strong northwest winds behind the cold front may gust up to 70km/h across parts of Ontario and Quebec. That wind will deliver colder air to our region. Temperatures will drop to or below the freezing point. Those gusty winds will also turn on the Great Lakes snow machine, with winter storm watches already in effect for parts of central Ontario as well as western New York. They are being issued early in anticipation of the big travel period associated with the American Thanksgiving holiday.

For our region, only flurries are expected on Thursday and Friday, with perhaps a little more snow as you head down Highway 401 towards Brockville and Kington.

Much colder air and the chance for some significant snow are possible for the first week of December in Montreal, as a much more winter-like pattern begins to evolve. High temperatures are expected to be below freezing by the middle of next week and remain there for the foreseeable future.

Another snowy Monday morning commute in Montreal

Above the snowy construction zone on the approach to the new Iles-aux-Tourtes Bridge along Highway 40 in Senneville Monday morning. Roads are snow covered and extremely slipper, especially off island. The snow should taper off Monday morning after an additional 3-5cm. (Valley Weather)

Mother Nature seems to be dictating the terms this November, leaving meteorologists and us amateurs alike a little surprised at times. Over the weekend, more rain than freezing rain fell for most of us, despite expectations of up to 10mm of ice. In total, 8.6mm of liquid precipitation fell late Saturday into early Sunday, morning, followed by close to 5cm of snow for Montréal. Snowfall amounts were much higher east and northeast of the city, where 10 to 20cm fell.

The system in question is now located over Prince Edward Island, but the broad circulation around the deepening low pressure is driving cold northwest winds across the St. Lawrence Valley and Great Lakes, producing numerous snow showers. Some locations, especially around the Great Lakes and the upslope higher elevations of the Eastern Townships, Green Mountain and Adirondacks can expect in excess of 20cm of snow through Monday.

Here in Montreal, the snow has been steady early Monday morning, but should taper off quickly today, with perhaps another 3 to 5cm of snow expected for the city. Unless of course Mother Nature feels like adding more.

The result has been a very slick commute in the city, with numerous accidents reported once again. One accident on the South Shore along Highway 30, resulted in a terrible commute from Chateauguay and neighbouring communities. Roads have been snow covered, especially off island. Visibility is also reduced at times in blowing and drifting snow, as winds gust from the northwest 30-50km/h. The winds will remain gusty into this evening. Temperatures will hover around the freezing point all day.

The message is always the same if you must drive, clean your windows and slow down. Winter tires are essential now, and mandatory in Quebec as of December 1st.