Coldest air of the season set to move into southern Quebec

We had more snow again this week in Montreal. So far this January, between 20 and 30cm of fresh snow has fallen across the metro region. We have had at least a trace of snow measured each day this month through January 16, with the exception of Friday, January 10. (Valley Weather Photo)

An arctic airmass will invade southern Quebec late this upcoming weekend, ushering in the coldest air so far this season, and likely colder than anything we experienced last winter.

Temperatures were very mild during the winter of 2023-2024, with no readings below -18C (0F) for the entire season in Montreal. So far this winter, I managed to just sneak below the -18C threshold at my home on Ile Perrot, down to -18.3C (-1F) on December 26. In general you need to go back to February 2023 for the last significant cold snap in the city. Montreal dropped to -29.3C (-21F) on February 4. That brief cold spell closed schools and strained Hydro resources for a day or two.

The upcoming arctic weather will not be that drastic, but will certainly feel much colder than most of us are accustomed to with the recent warmer-than-normal winters.

Before the cold air arrives, we are looking at yet another clipper system Thursday, that will be responsible for some nuisance snow, perhaps a dusting to 1cm. The flurries will end Thursday night, with partly cloudy skies expected on Friday. Expect very mild temperatures, with highs between 0C and -3C (27 to 32F) through Saturday and lows not falling far from those readings.

On Saturday, low pressure passing well north of Montreal will give us a shot of mild air on gusty south winds just in advance of a strong cold front. That front will cross the region late Saturday, accompanied by snow and gusty winds. Another front arrives late Sunday, with light snow and a reinforcing shot of cold air. By Monday, highs will struggle into the minus teens, with overnight lows through Wednesday morning colder than -20C (-4F) in Montreal. Windchill readings will drop into the minus 30s.

Arctic high pressure will settle over southern Quebec on Monday, with clear and frigid conditions forecast.

I will post further updates as the details become a little more clear. Plan for some very cold temperatures, dangerous windchills and more snow through the end of this month.

Critical fire weather remains across southern California

One of four Quebec Super Scoopers battling the flames in southern California over the past week. The CL-415 Aircraft is capable of scooping up 6000 litres of water in seconds. The battle from the air has been crucial in slowing the spread of the fires. The incredible photo was taken by @FIREPHOTOGIRL and posted on X.

Gusty Santa Ana winds continue to blow across southern California, along with critically low humidity readings. These conditions are expected to persist through Thursday before easing on Friday as winds turn more onshore bringing in a moist marine layer.

California is reeling from days of severe wildfires that have claimed at least 24 lives, resulted in evacuations of over 150,000 residents and destroyed over 15,000 dwellings. Many historic buildings have been lost, with entire neighbourhoods incinerated, including the picturesque Pacific Palisades.

According to Cal Fire, the Eaton Fire has consumed 14,000 acres and is 33 percent contained as of Tuesday morning. The Palisades Fire has scorched over 24,000 acres and is only 14 percent contained. The 2025 fire season is off to a fast start, well ahead of the 5-year average of 46 fires consuming 13 acres. To date there have been over 100 fires burning 39,000 acres.

Early estimates on damage are exceeding $250 billion, making the California Fires the costliest natural disaster in US history. Those amounts are only expected to rise.

The wildfires were the result of a perfect storm. Since October 1st, Los Angeles has recorded less than 1mm of rainfall, with only 4-7mm since May 1st. The tinder dry region was primed for a severe wildfire. Once started, they were driven by fierce Santa Ana winds that gusted over 120km/h. These winds are hot, dry winds the blow from the desert, howling through the mountain canyons to the Pacific Ocean. High pressure to the north, in this case over Idaho and low pressure to the south, squeezes the winds through the mountain passes, while drying out the atmosphere even more. The offshore winds easily spread any fire that may start. 

Investigators are still trying to determine the cause of the fire, which can range from electrical, such as in Maui, to lightning as is often the case here in Quebec, this was not the case in L.A., or by humans either in error or by arson. Once started, the powerful winds spread the fire quickly, at one point the Palisades fire was consuming as much as 5 football fields every minute. Embers can travel miles away igniting homes far from the fire source and creating new wildfires.

Canadian Help

Canada continues to help California, with aircraft from Quebec, Ontario, Alberta and British Colombia down south. This includes four CL-415 Super Scoopers from Quebec. One was damaged in a collision with a drone late last week, but landed safely. The plane remains grounded, but has been replaced along with additional crews. We have also sent at least 250 firefighters. Help has also arrived from 9 US States and Mexico.

More snow this week along with milder temperatures

Snow has fallen in Montreal on 12 of the 13 days so far this month. Amounts have not been all that impressive, with only 17.4cm falling at Trudeau Airport. Despite the light amounts, roads have often been icy and snow covered, with numerous accidents occurring across the region. You do not need a large accumulation of snow for dangerous travel conditions. Light amounts of snow often create very slippery roads and black ice. (Valley Weather Photo)

The active weather pattern will persist this week across southern Ontario and Quebec, with several weak systems impacting our weather. Monday morning features a clipper type low pressure moving across the region, accompanied by occasional light snow. The snow will make the roads greasy and messy as it did over the weekend, but will only amount to a couple of centimetres at best.

The one concern will be Monday afternoon along a trailing cold front. There is the chance for a few isolated snow squalls, that could produce brief heavy snow and gusty winds, reducing visibility. The best chance in the Montreal region will be between 3-6pm this afternoon. Along and behind the cold front, winds will back to the northwest and gust up to 40km/h.

Temperatures will be mild today, just below the freezing point in Montreal, and remain above normal for most of the upcoming week. Highs will be in the 0C to -4C (25 to 32F) range, with overnight lows around -8C (18F). If we manage any clearing overnight this week, with fresh snow cover, we may see some minus teens.

The week will remain unsettled, with several areas of weak low pressure moving rapidly from west to east. While precipitation amounts have been below normal so far in January, we have received at least a trace of snow everyday since the start of the month, with the exception of last Friday. As a result, 17.4cm of fresh snow has fallen at Trudeau Airport, with as much as 25cm in other parts of southern Quebec.

A stronger storm system is possible by next Saturday, followed by a significant push of arctic air. I will post more on that later, as well as an update on the devastating fires in southern California.

Cold snowy week for Montreal

Crews have been kept busy across southern Quebec, with snow falling each day so far this month. As of Wednesday morning, between 10 and 15cm has fallen across the Montreal region, with more east and southeast of the city. Another 5-10cm of likely over the next 24 hours, along with gusty west winds up to 50km/h and bitter windchills. (Valley Weather Photo)

Frigid air has settled over southern Quebec on Wednesday as stubborn low pressure northeast of the region draws down cold air. The upper low is also producing gusty northwest winds and occasional snow. Close to 5cm fell on the Montreal area on Tuesday, and another 5 to 10cm is likely over the next 24 hours. Blowing and drifting snow can be expected as well, due to the strong northwest winds.

The snow and very cold temperatures have left roads very slippery across the region. Winds have been gusting between 30 and 50km/h at Trudeau Airport, producing wind-chill values as cold as -25C (-13C) in Montreal. Temperatures will struggle to rise today and into the overnight period to around -10C (14F) by Thursday morning. Winds will remain gusty throughout the period, so conditions will be rather uncomfortable outdoors. Cloudy skies will persist on Thursday, along with few flurries. We may see a few peaks of sunshine on Friday, but temperatures will remain at or below normal for January for the foreseeable future.

FIRE & ICE

Winter weather has also been occurring across wide portions of the United States. A new storm this week will deliver snow and freezing rain across the deep south from Texas to the Carolinas. Meanwhile powerful Santa Ana winds have been driving fierce wildfires across the Los Angeles County region of southern California, pushing first responders to the limit. Nearly 1000 dwellings have been destroyed by the raging fires, that are being driven by winds in excess of 160km/h (100 mph). Two main fires, the Palisades and Hurst fires continue out of control on Wednesday. The Palisades alone fire has consumed over 3000 acres and is zero percent contained at this time.

Santa Ana winds have been howling across Southern California, driving fire storms that have destroyed entire neighbourhoods over the last 24 hours. Many fires are burning, stretching the limits of first responders. Fire conditions remain very dangerous Wednesday afternoon across LA County.

Chilly start to 2025 in Montreal

A major thaw resulted in all our snow melting away just prior to New Year's Day. Since then, we have had almost daily flurries and snow showers that have made roads slippery at times, and accumulated a general 5-10cm of snow across southern Quebec., More light snow and cold temperatures can be expected for the upcoming week. (Valley Weather Photo)

High pressure has been trying to nose into southern Quebec over the last few days, but a stubborn low pressure located well to the north of our region has been producing a cold northwest flow, along with occasional flurries and snow showers. The result has been cold blustery conditions of the last 48 hours, with nearly steady temperatures between -10C (14F) and -12C (10F). Winds have been between 20-40km/h, with a gust to 79km/h at Trudeau Airport on Thursday.

Most of the snow has been very light, but some isolated bands produced moderate snow briefly overnight into Sunday morning. Since January 1, between 5 and 10cm of snow has fallen across most of southern Quebec. Further west across the Great Lakes, very heavy lake effect snow fell in isolated bands, reducing visibility to zero at times, closing several highways immediately adjacent to the lakes in central and southern Ontario.

The same was true south of the border in western New York. Further south a strong winter storm was spreading snow and ice form the central plains, across the Ohio and Tennessee Valley and into the Middle Atlantic states. Freezing rain created havoc on roads across Kansas on Saturday, with hundreds of miles of interstates closed down after several multi-vehicle accidents.

In Montreal, we can expect cold temperatures to persist this week, but nothing exceptional, just January weather. Some light snow is possible on Monday evening into Tuesday morning, along with flurries through Thursday. We may briefly see the sun next Friday before another chance for snow arrives next weekend. At this time, none of the systems look particularly strong, with just a few centimetres expected.

Highs will range from -6C to -10C, with overnight lows between -10C and -17C. It is worth noting that if skies can manage to clear out and winds ease Sunday evening, some locations across the Montreal region may drop close to -20C (-4F). This would be the coldest night in the last two years. As I write, skies are clear in Montreal and the current temperature is -13C (7F).

Happy New Year!

With just a couple of hours to go in 2024, the year will end above freezing. The current temperature is 3.1C (38F) on Ile Perrot, we will not drop below 0C (32F) before midnight. A fitting end to what will likely be one of the warmest years on record for southern Quebec once the numbers are processed.

Precipitation is moving east across central Ontario currently and should arrive in the Montreal region during the pre-dawn hours New Years Day. Expect a messy mix of rain and snow throughout the day, along with dropping temperatures and increasing winds.

Have a very safe and happy new year, be kind to each other. Thank you for reading Valley Weather for the last 20 years...Stephen

Snow and cold return to Montreal to start 2025

While Christmas Eve was snowy and cold in Montreal, New Year's Eve looks more like early November. The record warmth of Monday has virtually eliminated all our snow in just a few hours. More snow is on the way however, as the weather pattern turns much colder and stormy to start 2025.

Happy New Year! 2025 will mark the 20th Anniversary of the Valley Weather Blog and the 46th year for Valley Weather. There was plenty of weather to talk about in 2024, none bigger than the billions of dollars in flood damage that occurred in Quebec from the remains of both hurricanes Beryl and Debby.

The year will end on a very mild note, we are currently 6C (43F) here on Ile Perrot, warm, but far from the 1875 record of 12.2C (54F). We did have a significant record high on Monday, reaching 11.4C (53F) at Trudeau Airport shattering the 2022 record of 8.6C (48F). Most of the snow cover has melted away, with the exception of a few patches here and there.

Winter will return however as we have a major pattern change on the way to begin 2025. It starts with deepening low pressure passing to our south across New England on New Year's Day, delivering steady precipitation across southern and eastern Ontario and Quebec. The storm will then head into Atlantic Canada.

The precipitation will start off as a messy mix of rain and snow, but as temperatures drop on Wednesday afternoon, all precipitation will change to snow. The snow will persist into Thursday morning, along with increasing winds out of the northwest and dropping temperatures. Accumulations will range from 5-10cm in valley locations to more than 15cm across the mountains of the Townships, Beauce, New York and New England. If you have travel plans on New Year's Day, expect highly changeable conditions with mixed precipitation and reduced visibility at times.

Look for windy, cold weather along with isolated flurries into the first weekend of the new year. Lows will drop into the minus teens, with daytimes highs struggling to rise above -10C (14F). The cold air will be with us well into the month of January.

Record warmth to end 2024 - winter will return this week

Before temperatures warmed Sunday evening, motorists were greeted with icy and foggy conditions late Saturday into Sunday morning. Since then however, temperatures have surged into the low teens in southern Quebec, and most of the snow on the ground has melted. Much colder weather returns by Thursday. (Valley Weather Photo)

A warm front finally lifted north of the St. Lawrence Valley early Monday morning, allowing very warm air to surge into southwestern Quebec. Granby reached 14C (58F), the warmest location in Canada, while Montreal settled in at 11C (52F), a new record high for the date, surpassing the previous of 8.6C (48F) set in 2022. Temperatures will slowly fall through the rest of the day Monday. Gusty winds are expected to develop, up to 50km/h at times.

After what was a very warm year, it is no surprise that we will end 2024 above freezing. While a cool front is on our doorstep this morning, temperatures are expected to remain well-above normal, right into New Year's Day. The weekend freezing rain and fog has dissipated, and now warm southwest winds and rain are eating away whatever snowpack was left in Montreal. Over the last few hours, we have recorded close to 10mm of rain.

This is a good time to remind everyone to stay away from area lakes and rivers. The ice is thin, unstable and dangerous, and the water is frigid and moving quickly.

As far as practical weather goes, we can expect showers to persist off and on through New Year's Eve, along with dropping temperatures. Temperatures should remain above freezing through Wednesday. By mid week, low pressure will develop along the east coast and draw in much colder air into Montreal, along with a swath of snow across our region. Depending on how fast we cool down here in the St. Lawrence Valley, we may be looking at 5-10cm of snow on the ground by Thursday morning.

The snow will be followed by an arctic blast that will plunge temperatures below freezing across much of eastern North America. The extended forecast for January across most of southern Ontario, Quebec and New England, is for cold and snowy conditions, perhaps a more typical Montreal January for a change.

Time will tell...