January 12, 2025

Intense Snow Squalls Return to Parts of Southern Ontario on Monday; Possible Deep Freeze for Late January

January 12, 2025/ Brennen Perry

***NOTE: YOU CAN CLICK ON THE MAP TO OPEN A ZOOMABLE IMAGE***

⬇️ ZOOMED IN MAP CAN BE FOUND FURTHER DOWN ⬇️

The first half of January is almost behind us, and in Southern Ontario, the weather has shifted significantly compared to December. Colder temperatures have dominated, leading to several bouts of snow squall activity off Lake Huron and Georgian Bay. These events have primarily impacted regions southeast of the lakes.

The threat of snow squalls is set to return this week, with the heaviest snow expected east of Lake Huron and Georgian Bay. A predominant westerly flow will target areas such as Parry Sound, Bracebridge, Gravenhurst, and parts of Grey and Bruce counties. This pattern is reminiscent of what we experienced in early December, with heavy snow focused in the snowbelt regions east of Georgian Bay.

Snow squalls are forecasted to develop Monday afternoon and further intensify into the evening and overnight hours. Rapid snowfall accumulation and near-zero visibility are likely, especially late Monday into early Tuesday.

By the time the squall activity tapers off on Tuesday afternoon, some localized areas in the Muskoka and Parry Sound regions could see totals between 25 and 50 cm.

A brief reprieve from lake-effect snow is expected after Tuesday as milder air moves into Southern Ontario. However, another Arctic plunge is anticipated by early next week, potentially bringing some of the coldest air of the season.

Wind chills could make it feel like -30°C or even -40°C, especially in Central and Eastern Ontario!

This upcoming cold snap could also reignite intense lake-effect snow activity, with several rounds of squalls likely to impact the snowbelt regions throughout the rest of January.

BREAKING DOWN THE TIMING OF THE SQUALLS

Before the snow squalls begin Monday, a weak clipper system is forecasted to move across Southern Ontario late Sunday into early Monday morning. While this system will lack significant moisture, it may bring light snowfall of 2 to 5 cm in most areas, with localized pockets potentially reaching up to 5 cm.

**HOURLY SNOWFALL RATE/intensity** - MAP FROM WEATHERBELL

In the wake of the clipper, lake-effect snow is expected to ramp up east of Georgian Bay on Monday afternoon. Initially, the snow may be disorganized, spreading moderate to heavy snowfall across Muskoka and parts of Grey and Bruce counties.

By Monday evening, forecast models indicate the formation of a more organized snow squall. This band is expected to stretch from the Bruce Peninsula across Georgian Bay and inland between MacTier and Parry Sound.

The squall could remain stationary overnight, leading to rapid snowfall accumulation at rates of 5 to 10 cm per hour.

Model projections differ slightly regarding the exact placement of the most intense squall. The American model places the heaviest snow over Parry Sound, Pointe au Baril, Sprucedale, and Burk’s Falls.

Meanwhile, the Canadian model suggests the squall may shift south after midnight, targeting areas such as Port Carling, Rosseau, Port Sydney, and Bracebridge for the heaviest snowfall.

Both models agree that the squall will gradually sink southward by late Tuesday morning, bringing heavy snow to northern Simcoe County, including Midland and Orillia.

However, there is uncertainty about the intensity and duration of the squall as it moves further south into Barrie.

While Georgian Bay will see the most intense squalls, Lake Huron is also expected to generate less intense snow bands Monday evening into Tuesday morning. These bands could impact Owen Sound, Kincardine, and Hanover, with bursts of heavy snow.

As the wind shifts southward, areas like Goderich and London may briefly experience lake-effect snow Tuesday morning into the afternoon.

WHO COULD GET BURIED IN SNOW

As is typical with lake-effect snow, snowfall totals will vary widely depending on where the narrow bands persist. The highest accumulations are expected in Parry Sound, Rosseau, Port Carling, Port Sydney, Bracebridge, and Gravenhurst, where 25 to 50 cm of snow is possible by Tuesday afternoon.

In some areas, totals could exceed 50 cm if the squall remains stationary for an extended period.

Surrounding areas such as Midland, Washago, Coboconk, Minden, Huntsville, and Sprucedale may see snowfall totals of 15 to 25 cm.

The Grey-Bruce region, including Kincardine, Port Elgin, Wiarton, Lion’s Head, Tobermory, Owen Sound, Chatsworth, Hanover, and Meaford, is expected to receive 15 to 25 cm, with localized totals of 30 to 40 cm if squalls intensify.

Elsewhere in Central and Southwestern Ontario, snowfall amounts will range from 5 to 15 cm, combining accumulation from the weak clipper system and lake-effect snow. Most areas will see closer to 5 cm, with lake-effect zones reaching 10 to 15 cm.

Less than 5 cm is expected for the rest of Southern Ontario.

SNOW SQUALL WATCH ISSUED BY ENVIRONMENT CANADA

CURRENT ENVIRONMENT CANADA ALERTS AS OF SUNDAY EVENING

Environment Canada has issued snow squall watches for areas around Lake Huron, Georgian Bay, and Lake Superior.

The highest totals in these watches match our forecast, with 20 to 40 cm expected for Parry Sound and Muskoka and 15 to 25 cm for the Grey-Bruce region.

Northern Ontario, including Sault Ste. Marie and Manitoulin Island could see localized snowfall of 10 to 20 cm from Monday evening into Tuesday morning.

LOOKING AHEAD TO THE REST OF JANUARY

The persistence of lake-effect snow this far into January may seem unusual, but the Great Lakes remain relatively ice-free and warmer than usual due to a mild fall and warm start to winter. This provides ample moisture for snow squalls when Arctic air moves in.

**ICE COVERAGE MAP AS OF JANUARY 11, 2025** - source: NOAA

Colder weather in recent weeks has helped cool the lakes and increased ice coverage, particularly in shallower areas like Lake Erie and the shorelines of Lake Huron and Georgian Bay.

Ice coverage has risen from 1% at the start of January to over 10% as of January 11.

**TEMPERATURE ANOMALY** - MAP FROM WEATHERBELL

Looking ahead, a significant Arctic blast is expected during the January 20–24 period, with temperatures 10 to 20 degrees below seasonal norms across much of Southern Canada and the northern U.S.

Southern Ontario could experience lows well below -20°C, potentially nearing -30°C in some areas. Wind chills could make it feel as cold as -35°C to -40°C, particularly in Central and Eastern Ontario.

This intense cold will likely bring additional snow squalls and accelerate ice formation on the Great Lakes. If current trends continue, lake-effect snow activity could diminish significantly by the end of the month as ice coverage increases, shutting off the moisture source for squalls.

For snowbelt residents weary of lake-effect snow, relief may finally be on the horizon!

January 10, 2025

Looking Back on Canada's Costliest Winter Disaster: The Ice Storm of January 1998

January 10, 2025/ Alannah Campbell

*A downed hydro pylon in Quebec following the ice storm in January 1998, courtesy of* *CBC News*.

As Canadians rang in the New Year in January 1998, millions were unaware that in only a few days, they’d be caught in the middle of the costliest natural disaster in Canadian history. This is a record that stood for over 18 years, until the Fort McMurray fire of 2016. Nevertheless, it remains the most expensive winter disaster Canada has ever seen.

A 40,000km² area that covered Eastern Ontario and Upstate New York, up the St Lawrence Valley through Montreal, into the Eastern Townships of Quebec and across Maine into New Brunswick was coated in up to 100mm of ice that fell as freezing rain from the 5th until the 10th of January 1998. Light freezing rain was even experienced in Waterloo Region, to the west of Toronto and extended as far east as Western Nova Scotia. It’s important to note that this wasn’t a single storm, but rather a series of three smaller storms that produced freezing rain and ice pellets over an almost week-long period.

The Christmas Break in December 1997 was cold and snowy across much of Southern Ontario and Quebec so it was refreshing when New Year’s Day brought mild temperatures and sunshine to the region. However, a concerning weather pattern was shaping up.

*The surface chart from January 7th, 1998 showing the positions of the high and low pressure, areas of precipitations (shaded in darker grey) and the temperatures in degrees Fahrenheit, courtesy of* *the National Weather Service*.

In the coming days, a strong high pressure area settled over Northern Quebec, which forced cold Arctic air southwards, while multiple low pressure systems from the south funnelled warm, moist air northwards. When the two air masses collided, the warm air rose above the cold air and then when the rain fell from the warm air mass, it froze on contact with surfaces at ground-level where the air was much colder.

This is what typically occurs in freezing rain events, but what made this different was the persistent flow of warm, moist air straight from the Gulf of Mexico continuing over several days, turning this into a prolonged event.

Temperature Profiles and the formation of different precipitation types.

The moist Gulf air arrived first, on January 4th, and brought mild temperatures and light rain to most of the impacted region. The next day, the Arctic air moved in and settled below the warmer air mass, bringing surface temperatures back below freezing and resulting in the transition from rain to freezing rain.

The high pressure continued to build over Northern Quebec throughout the following days, which maintained the flow of Arctic air, while the moist Gulf air surged northward in three distinct rounds of precipitation. According to Environment Canada, these three waves were: from 6:00pm on January 5th to 8:00am on January 6th, from 6:00pm on January 7th to 8:00am on January 8th, and from the morning of January 8th until the morning of January 9th.

Overall, an average of 50-70mm of freezing rain fell across the entire region. However, an area later called the “Triangle of Darkness”, between the towns of Saint-Hyacinthe, Granby, and Saint-Jean-sur-Richelieu, was hit the hardest, with more than 100mm of ice accretion.

*Total Ice Accretion amounts from the January 1998 Ice Storm, courtesy of* *the National Weather Service*.

*Map of the total Ice Accretion from the January 1998 Ice Storm, with a Focus on Eastern Ontario and Southern Quebec, Courtesy of* *Hydro Quebec*.

It didn’t take long for the effects of the ice buildup to be felt. Transportation quickly came to a halt as roads and sidewalks became skating rinks and vehicles were completely encased in ice.

After 10-20mm of freezing rain from the first round of precipitation, tree branches were already bending under the weight of the ice and as more freezing rain fell, the branches broke and entire trees toppled. Residents reported that the continuous sounds of ice-covered trees and branches breaking and falling was akin to gunshots. No definitive number was ever established, but it is estimated that millions of trees fell as a result of this storm.

It was also early on in the event that the strain on the power grid was felt and it only got worse as the freezing rain continued. Transmission lines sagged with the extra weight and short circuits caused by ground wires sagging and touching live wires tripped switches. Fasteners responsible for holding these lines were unable to handle the extra weight from all of the ice and snapped, while entire hydro poles and large towers eventually collapsed.

On top of all of this, transformers were damaged and caught fire, leading to further destruction of the hydro distribution system. Overall, 1,000 hydro pylons crumpled and at least 30,000 hydro poles were destroyed, plunging over 4 million people in Ontario, Quebec, and New Brunswick into darkness.

*A montreal street covered in ice from the January 1998 ice storm, courtesy of* *Hydro Quebec*.

While most people who were impacted by the ice storm were in urban areas, two groups in particular were significantly impacted in rural regions.

The stretch of the country hit by the ice storm was home to roughly 25% of all dairy cows in Canada and farmers encountered considerable challenges with the loss of power. Many cows got sick when it became difficult to feed them, milk them, and keep them warm.

With the lack of power at processing plants, over 10 million litres of milk, worth roughly $5 million, had to be dumped. Hydro Quebec reports that it was able to provide generators to many cattle farmers in the province, but unfortunately an estimated 300,000 farm animals across the entire region died in the cold.

Quebec’s maple syrup industry also took a massive hit with the ice storm. More than 20% of syrup-producing trees were damaged or destroyed as branches fell or large pieces of the trees splintered off, and equipment collapsed under the weight of the ice. Some syrup producers had their entire sugar bushes destroyed and while trees and the industry have mostly recovered, some scars still remain.

*A convoy of troops deployed from Petawawa en Route to aid victims of the ice storm, taken January 9th, 1998, Courtesy of* *Veterans Affairs Canada*.

On January 7th, at the peak of the ice storm, the Provincial Governments of Ontario, Quebec, and New Brunswick appealed to the Federal Government for assistance. The next day, 15,000 members of the Canadian Armed Forces were deployed from 200 different units from across the country as part of Operation Recuperation, making this this largest peacetime deployment of troops in Canadian history.

Troops worked with hydro companies to help restore power, cleared tree limbs and other debris, evacuated residents, and provided shelter, food and medical care to victims. The Operation eventually concluded on February 28th, 1998.

Due to the sheer level of damage across such a large area, the cleanup of debris and restoration of power was not something that was going to occur overnight. Temperatures plummeted following the ice storm to -20°C, so staying warm was the number one concern in the aftermath.

Many people were able to stay with family and friends who still had power, but emergency shelters were set up and available for those with nowhere else to go. Approximately 600,000 people were temporarily displaced from their homes while crews worked to restore power.

Thankfully, hydro crews from across the country and the United States came to the aid of those in the disaster area. The power was restored to many people in urban areas after a few days, but efforts took longer in rural communities, with roughly 700,000 people still without power three weeks after the storm.

The ice storm was a real testament to the sense of community as well as the welcoming and giving nature of Canadians. Many people came together to help clean up and provide food and shelter to those in need. Despite all this, the storm resulted in 945 injuries and 35 people sadly lost their lives.

On top of the human cost, the storm had a very large financial cost. The incredible amount of damage caused by this storm was estimated to have cost insurers $1.38 billion. Furthermore, entire cities were shut down and 2.6 million people in Ontario and Quebec, consisting of close to a fifth of the Canadian workforce, unable to get to work. The loss of productivity was over $1 billion and when added to insured damages and the over $2 billion it cost to repair utilities, the overall financial cost of the storm is estimated at $5.4 billion.

Further Reading:

https://canadiangeographic.ca/articles/lessons-learned-from-the-ice-storm-of-1998/

https://www.cbc.ca/news/canada/montreal/ice-storm-1998-1.4469977

https://www.hydroquebec.com/ice-storm-1998/

https://www.thecanadianencyclopedia.ca/en/article/ice-storm-1998

https://www.veterans.gc.ca/en/remembrance/wars-and-conflicts/caf-operations/service-in-canada/ice-storm

https://www.weather.gov/btv/25th-Anniversary-of-the-Devastating-1998-Ice-Storm-in-the-Northeast

January 03, 2025

Snow Squall Blast Continues This Weekend as Parts of Southern Ontario Could See an Additional 25-50cm of Snow

January 03, 2025/ Brennen Perry

The New Year has certainly started on a snowy note for parts of Ontario's snowbelt regions. A multi-day snow squall event is underway around Lake Huron and Georgian Bay, with some areas already receiving over 50 cm of snow. Locations east of Lake Huron, Simcoe County, and parts of Kawartha Lakes have been among the hardest hit so far.

While the activity off Georgian Bay weakened somewhat on Friday evening, it's expected to ramp up again by Saturday afternoon and continue through Sunday. Snow squalls will also persist east of Lake Huron Friday night into Sunday, though the bands will shift around multiple times during this period.

By the end of the weekend, some areas could see an additional 25 to 50 cm of snow, with localized totals reaching as high as 75 cm. Combined with the snow that has already fallen, totals in the hardest-hit regions could exceed one meter (100 cm). This includes parts of Simcoe County, where 50 to 75 cm of snow has already accumulated over the past two days.

As of Friday evening, multiple discrete squalls off Lake Huron are bringing heavy snow to areas stretching from Bayfield to Kincardine and as far inland as Woodstock, Kitchener, and Guelph. This activity is expected to continue through the night, with southern squalls gradually merging northward by early Saturday morning.

The New Year has certainly started on a snowy note for parts of Ontario's snowbelt regions. A multi-day snow squall event is underway around Lake Huron and Georgian Bay, with some areas already receiving over 50 cm of snow. Locations east of Lake Huron, Simcoe County, and parts of Kawartha Lakes have been among the hardest hit so far.

While the activity off Georgian Bay weakened somewhat on Friday evening, it's expected to ramp up again by Saturday afternoon and continue through Sunday. Snow squalls will also persist east of Lake Huron Friday night into Sunday, though the bands will shift around multiple times during this period.

By the end of the weekend, some areas could see an additional 25 to 50 cm of snow, with localized totals reaching as high as 75 cm. Combined with the snow that has already fallen, totals in the hardest-hit regions could exceed one meter (100 cm). This includes parts of Simcoe County, where 50 to 75 cm of snow has already accumulated over the past two days.

As of Friday evening, multiple discrete squalls off Lake Huron are bringing heavy snow to areas stretching from Bayfield to Kincardine and as far inland as Woodstock, Kitchener, and Guelph. This activity is expected to continue through the night, with southern squalls gradually merging northward by early Saturday morning.

By Saturday morning, an intense squall is expected to form between Sauble Beach and Kincardine, extending inland to areas such as Hanover, Dundalk, and Orangeville. This band may stretch as far east as the western GTA, including Mississauga and Brampton.

While overall accumulations in the GTA should remain around 5 cm or less, these squalls could still lead to near-zero visibility and hazardous travel conditions due to blowing snow.

For Georgian Bay, lingering lake-effect activity will continue Friday night into Saturday morning, though no significant squalls are expected until later in the day.

By mid to late Saturday afternoon, the Lake Huron squall is expected to shift northward as wind directions change. This will allow it to cross over the southern Bruce Peninsula and connect with Georgian Bay, bringing heavy snowfall to Simcoe County, particularly in the Barrie-Orillia corridor.

This squall may also extend into parts of northern York and Durham regions, as well as the Kawartha Lakes region.

As seen earlier in this event, the squall is expected to lock in place, leading to intense snowfall rates of 5 to 10 cm per hour late Saturday through Sunday. Driving conditions will deteriorate rapidly, and non-essential travel should be avoided due to the potential for road and highway closures.

By late Sunday morning, the Georgian Bay squall is expected to sink southward, bringing an end to the snow for areas southeast of the bay. Moderate to heavy lake-effect snow may persist in parts of Grey and Bruce counties throughout Sunday, with activity finally tapering off overnight into Monday morning.

The heaviest snowfall totals are expected in areas such as Wiarton, Owen Sound, Kincardine, Hanover, Meaford, Collingwood, Wasaga Beach, Midland, Barrie, Orillia, and Beaverton. These regions could see an additional 25 to 50 cm of snow by the end of the weekend, depending on the squall locations.

Surrounding areas, including Goderich, Woodstock, Stratford, Kitchener, Guelph, Angus, Bradford, Lindsay, and Port Perry, may also see significant snowfall if the squalls align. These areas could receive 15 to 25 cm of snow, though amounts will vary widely due to the localized nature of snow squalls. Our forecast is intentionally broad to account for potential shifts in squall placement.

Snowfall amounts will drop off quickly outside the snowbelt regions. However, parts of the northern and western GTA could see 5 to 10 cm, with isolated amounts up to 15 cm. Even Toronto might get a few centimeters of brief, heavy snow as the bands shift inland.

Eastern and Deep Southwestern Ontario are not expected to see any significant snowfall from this event.

January 01, 2025

Snowy Start to 2025 in Ontario’s Snowbelt; Squalls Could Deliver Up to 50cm of Snow by End of Week

January 01, 2025/ Brennen Perry

As we kick off the New Year across Ontario, we’re starting off with a blast of cold Arctic air that moved into the region over the past 24 hours. With this chilly air comes the inevitable return of lake-effect snow in the traditional snowbelt areas surrounding Lake Huron, Georgian Bay, and Lake Superior.

Strong snow squalls are anticipated to develop Wednesday evening and are likely to persist through Thursday and into Friday. These squalls are expected to bring intense snowfall rates of 5-10 cm per hour, along with near-zero visibility that will make travel nearly impossible in the hardest-hit areas.

The main focus for this lake effect activity will be in parts of Huron, Perth, Grey, Bruce, and Simcoe counties. Depending on where these narrow snow bands establish, localized accumulations could approach or exceed 50 cm by week’s end, with additional snowfall possible through the weekend as the lake effect machine remains active.

Disorganized squalls are expected to begin forming off Lake Huron and Georgian Bay late Wednesday evening or around midnight. According to the latest data, multiple bands could develop off Lake Huron, with one possibly targeting areas south of Owen Sound.

Another band may stretch from Goderich inland towards Stratford and St. Marys, just north of London. However, there remains some uncertainty about where exactly these squalls will set up, which will determine the heaviest snowfall locations.

For Georgian Bay, models show differing timelines. One suggests squall activity could begin just after midnight, while another predicts development near sunrise on Thursday. If squalls form, areas like Wasaga Beach and Barrie could be affected overnight.

Overnight, the bands that do form may shift around and dissipate periodically, spreading snowfall over a broader area. If a squall locks into place unexpectedly, snowfall can accumulate rapidly in a short time.

The event is expected to intensify by mid to late Thursday morning as the northern squall off Lake Huron drifts northward, potentially crossing the Bruce Peninsula and reconnecting over Georgian Bay. This setup could lead to a rare "multi-lake connection," allowing the squall to draw moisture from a long stretch of open water.

The result would be heavy snowfall affecting areas such as Owen Sound, Collingwood, Wasaga Beach, and Barrie, with possible extensions into Durham Region and southern Kawartha Lakes.

Another squall off Lake Huron could extend inland into Huron and Perth counties, with potential impacts as far as Kitchener-Waterloo. While intense snowfall could occur, squalls are notoriously narrow, and not all areas will be directly affected.

By late Thursday afternoon, snow squalls off Lake Huron may weaken as the wind shifts more westerly, reducing the available lake surface from which the squalls can pull moisture. The Georgian Bay squall, however, could continue intensifying and shift northward, potentially impacting areas like Midland and Orillia while giving Barrie a break.

There remains uncertainty regarding the squall's position, with some models suggesting it may remain south of Orillia. If the squall locks in place overnight, areas such as Simcoe County and southern Kawartha Lakes could see prolonged periods of heavy snow, leading to extremely poor travel conditions, potential road closures, and significant snowfall accumulations.

By late Friday morning, shifting winds are expected to push the Georgian Bay squall southward, potentially dissipating it by midday. However, lake effect activity off Lake Huron may persist southeast of the lake into areas like Kitchener and London through Friday afternoon and evening.

The hardest-hit regions from this event will likely include Grey-Bruce and southern and central Simcoe County, including Wasaga Beach and Barrie. Snowfall totals in these areas could range from 25 to 50 cm by Friday night.

Some localized spots, particularly between Barrie and Orillia, may see totals exceeding 50 cm, with the potential for as much as 75 to 100 cm. However, model disagreement prevents us from confidently forecasting such extreme totals.

It’s important to note that snow squalls are highly localized phenomena, often only a few kilometres wide. While our forecasts aim to highlight the most likely zones, the reality is that squalls can shift unexpectedly, meaning not every location in a forecasted zone will see the same impacts.

Surrounding areas, including Orillia, Lindsay, Fenelon Falls, and Port Perry, could see localized snowfall of 15-25 cm from the Georgian Bay squall, with totals tapering quickly outside of this zone. Peterborough and areas along the Lake Ontario shoreline between Oshawa and Brighton may see 5-15 cm.

For regions east of Lake Huron, a narrow band from Goderich to Wingham and Listowel could see 25-50 cm of snow, with some extension into Kitchener, where totals may approach 15-20 cm. However, the exact setup will depend on the squall’s inland reach.

Elsewhere, the Golden Horseshoe could see a few centimeters of snow from brief, heavy bursts of lake effect activity, but no significant accumulations are expected. Areas north of Bracebridge, east of Peterborough, and south of Woodstock are likely to see little to no snow.

As always, lake effect snow forecasts carry inherent uncertainty. While many areas may receive less snow than forecasted, those directly in the path of these intense squalls could see the full brunt of the snowfall. Be prepared for rapidly changing conditions, and avoid non-essential travel in the hardest-hit zones.

Snow squalls are also expected to affect regions east and southeast of Lake Superior in Northern Ontario starting Wednesday evening. These squalls will continue to persist throughout the day on Thursday before shifting south of the border.

The Sault Ste. Marie region appears to be in the bullseye and could see localized snowfall totals between 25 to 50cm by the time the snow tapers off late Thursday.

December 31, 2024

Heavy Snow Could Impact New Year’s Eve Celebrations in Southern Ontario With Up to 10-20cm of Snow

December 31, 2024/ Brennen Perry

After a brief return to milder weather accompanied by heavy rain to cap off the final weekend of the year, a snowy blast is on the horizon to kick off the first few days of 2025.

A system is expected to move into Southern Ontario starting Tuesday afternoon, bringing a mix of precipitation that will gradually transition to snow as we ring in the New Year at midnight. For those heading out to celebrate New Year’s Eve, road conditions may become hazardous, particularly later in the evening as temperatures drop below freezing.

Snowfall is expected to continue throughout New Year’s Day on Wednesday, with the heaviest accumulation focused on parts of Central and Eastern Ontario. By the time the snow tapers off late Wednesday, some areas could see snowfall totals nearing 10 to 20 cm in the hardest-hit regions.

In the wake of this system, frigid Arctic air is set to return, dominating the weather pattern for at least the first week of 2025. With the Great Lakes still largely unfrozen, the lake-effect snow machine is expected to roar back to life, potentially resulting in a multi-day snow squall event.

Starting Thursday and continuing into the weekend, some areas in the traditional snowbelt regions near Lake Huron and Georgian Bay could see significant snowfall, with totals approaching 50 cm by the end of the weekend.

**PRECIPITATION TYPE** - MAP FROM WEATHERBELL

The New Year’s Eve system is forecast to bring the first scattered bands of precipitation into the region from the south and west during the early to mid-afternoon hours on Tuesday. Areas in Deep Southwestern Ontario and near the Lake Erie shoreline will be affected first, with the precipitation gradually spreading across Southern Ontario by the dinner hour.

At this time, most regions are expected to hover near or just above the freezing mark, particularly in the Golden Horseshoe, where temperatures are likely to range between 3 and 5°C. As a result, the precipitation will likely begin as scattered rain or drizzle in many areas.

However, higher elevations northwest of the Greater Toronto Area (GTA) and into Central Ontario may see a mix of rain, ice pellets, and wet snow as temperatures there will be closer to freezing.

By the evening, the heaviest precipitation is expected to be concentrated east of Lake Huron, extending into Central Ontario. This will increasingly fall as wet snow as temperatures cool. Meanwhile, regions near the shores of Lake Ontario and Lake Erie will see less sustained precipitation, with rain continuing to dominate, especially near the lakeshore.

As the clock strikes midnight to welcome the New Year, heavy snow will continue in Central & Southwestern Ontario, while moderate to heavy rain will likely persist along the Lake Ontario and Lake Erie shorelines, dampening New Year’s Eve celebrations in the GTA and Niagara region.

Overnight, the precipitation is expected to transition to heavy, wet snow across most areas as colder air moves in behind the system. However, areas close to the Lake Ontario shoreline, including Hamilton, Toronto, and Kingston, may continue to experience rain into the early hours of Wednesday. Wet snow may mix in later in the morning, but periodic rain is likely as temperatures hover near freezing throughout Wednesday afternoon.

Moderate to heavy snow is forecast to persist through Wednesday in Eastern and Central Ontario, tapering off in Southwestern Ontario by the evening. In Eastern Ontario, steady snow could continue past midnight, finally ending early Thursday morning. Some lake-effect snow may develop off Lake Huron and Georgian Bay as early as Thursday morning.

Snowfall totals are challenging to predict for this system due to temperatures hovering close to freezing, which could significantly impact snow accumulation. A slight shift in temperatures could cause the system to overperform or underperform expectations.

The highest snowfall totals are expected in higher elevations of Central and Eastern Ontario, including Sundridge, Huntsville, Algonquin Park, North Bay, Deep River, and Bancroft. These areas could see between 10 and 20 cm of fresh snow by Thursday morning.

A wide swath of Southern Ontario, including much of Eastern Ontario, the Lake Simcoe region, and parts of Southwestern Ontario, is forecast to receive between 5 and 10 cm of snow. Localized areas may exceed 10 cm and approach 15 cm.

Around 2 to 5 cm of snow is expected for Ottawa, Brockville, Kingston, Belleville, and the northern GTA (away from the shoreline), where mixing will reduce overall snowfall amounts.

Limited accumulation is expected near the shorelines of Lake Ontario and Lake Erie, as well as in Deep Southwestern Ontario, including Windsor and Chatham, where temperatures will likely remain too mild for significant snow accumulation.

After the system snow, attention will shift to the risk of snow squalls beginning Thursday and lasting several days into the weekend. Snow squalls are highly localized events, often producing intense snowfall within narrow bands only a few kilometres wide which can make it hard to pinpoint exactly who will see the worst conditions.

Current models suggest a dominant northwesterly wind direction for much of this period, historically favouring heavy snowfall in parts of Grey and Bruce counties off Lake Huron. Squalls off Georgian Bay are expected to target Simcoe County (Midland, Orillia, Barrie), Muskoka (Bracebridge, Gravenhurst), and the Kawartha Lakes region.

Locations such as Orillia, Midland, Wasaga Beach, Wingham, Mildmay, Hanover, Chatsworth, Owen Sound, and Flesherton could see up to 50 cm of snow by the end of the weekend. However, not all areas will experience these extreme totals due to the localized nature of snow squalls.

Stay tuned for updates as higher-resolution models provide more precise forecasts. For now, be aware that travel in snowbelt regions could be significantly impacted starting Thursday, with the potential for rapid snowfall accumulation and blowing snow leading to near-zero visibility and possible road closures.

December 22, 2024

A Nightmare Before Christmas as Snowstorm Targets Southern Ontario on Monday With Up to 10-20cm of Snow

December 22, 2024/ Brennen Perry

Are you dreaming of a White Christmas? Well, it looks like luck is on your side as a snowy system is poised to sweep across Southern Ontario just days before Christmas. However, this snowfall won’t come without consequences, as it is expected to bring a significant amount of snow to some areas and could disrupt holiday travel plans right before Christmas.

Snow is anticipated to start early Monday and persist throughout the day, bringing moderate to heavy snowfall across a wide area of the region. Central and Eastern Ontario are likely to bear the brunt of this storm, with total snowfall amounts ranging from 10 to 20cm expected by early Tuesday morning.

In contrast, Deep Southwestern Ontario and areas along the Lake Ontario shoreline, including the Greater Toronto Area GTA, are expected to experience lesser impacts from this system. This is primarily due to the majority of the precipitation staying further north, and any moisture reaching the south being met with slightly warmer air, resulting in wetter snow and reduced accumulation.

According to the latest data, initial bands of snow are projected to move into the Bruce Peninsula and Georgian Bay areas by mid to late morning on Monday. The snow will then spread eastward, encompassing Eastern Ontario and all regions by early afternoon.

The heaviest snowfall is likely to be concentrated east of Georgian Bay, possibly enhanced by minor lake effects. By late afternoon, snowfall will also begin in Southwestern Ontario, with a chance of some mixing, including ice pellets and wet snow, particularly in Deep Southwestern Ontario around Windsor.

The most challenging conditions are expected during the afternoon and evening hours, as steady snow covers much of Southern Ontario. Occasional moderate wind gusts up to 40 km/h may lead to blowing snow and reduced visibility. If travel is necessary during this time, exercise extreme caution, and consider postponing travel until Tuesday when conditions are expected to improve significantly.

Temperatures are forecasted to gradually warm up during the evening, approaching the freezing mark around Lake Ontario and Lake Erie. This may cause existing snow to transition to a mix of wet snow and rain, potentially resulting in lower snowfall totals in these areas.

Light snow will continue past midnight into early Tuesday morning but will diminish in intensity as the night progresses. Western regions should see snow taper off shortly after midnight, while Eastern Ontario may experience lingering snow until late morning.

Overnight, there is concern about rain mixing in along the Golden Horseshoe as temperatures rise further, potentially melting any earlier snow and jeopardizing the chances of a White Christmas in those areas. We will closely monitor this development as it unfolds.

Snowfall accumulation is expected to range from 10-20cm across Central and Eastern Ontario, including areas like Grey-Bruce, Barrie, Orillia, Huntsville, North Bay, and the Ottawa Valley. Some localized spots, particularly east of Georgian Bay and into the Ottawa Valley, could see up to 25cm of snow.

Further south and west, 5-10cm of snow is anticipated east of Lake Huron, extending into the Golden Horseshoe away from the shoreline, including cities like London, Woodstock, Kitchener, Guelph, Mississauga, and Orangeville.

Toronto, Oakville, Burlington, Hamilton, the Niagara region, and Deep Southwestern Ontario, such as Chatham, Sarnia, and Windsor, are expected to receive less than 5cm of snow. Windsor may see minimal snow if the transition to rain occurs earlier than anticipated. There remains a possibility for the GTA to exceed forecasted amounts if cold air persists and prevents mixing.

December 19, 2024

Snow Squall May Disrupt Friday Morning Commute in the GTA; Locally 10-20cm of Snow Possible

December 19, 2024/ Brennen Perry

Southern Ontario has enjoyed a relatively calm week of weather, offering a welcome break for those still recovering from the heavy snow squalls that hammered parts of the snowbelt earlier this month. However, as the saying goes, all good things must come to an end, and this tranquil pattern is set to change as we approach the end of the week.

For a twist, the snowbelt won’t be the epicenter of the heaviest snowfall this time. Instead, the Greater Toronto Area (GTA), which has largely avoided winter’s worst so far, will be in the spotlight.

A weak system is forecast to sweep across Southern Ontario late Thursday into Friday, but the real story lies in a rare phenomenon: lake-enhanced snowfall and localized snow squalls along the western shoreline of Lake Ontario. These conditions could deliver a sudden 10-15 cm of snow, with localized totals nearing 20 cm in parts of the western GTA between Thursday night and early Friday morning.

Most other areas in Southern Ontario will see much less snow, with accumulations generally staying under 5 cm. As you move into Central and Eastern Ontario, snowfall will likely be limited to trace amounts. After the snow, attention will shift to an impending blast of Arctic air this weekend, bringing wind chills as cold as -30°C on Sunday and Monday.

The snowfall is expected to begin in Deep Southwestern Ontario on Thursday evening, with light to moderate bands moving eastward. While initial impacts will likely be minimal, drivers should still exercise caution as roads may become slushy with reduced visibility. By midnight, the snow will have reached the Golden Horseshoe, blanketing the region with light to moderate snowfall through the early hours of Friday.

A key feature of this system will be a concentrated band of heavy snow forming off Lake Ontario, likely impacting areas between Toronto and Burlington early Friday morning. This narrow band could initially affect Toronto and Mississauga before shifting southward into Oakville, Burlington, and eventually Hamilton. If this snow squall becomes stationary for an extended period, it could deliver intense snowfall rates of 2-4 cm per hour, rapidly accumulating 10-15 cm or more in a short time.

This timing is particularly concerning as the squall is expected to peak during Friday’s morning rush hour. Commuters in the western GTA should prepare for challenging conditions, including near-zero visibility and rapidly deteriorating roads. By early Friday afternoon, the lake effect activity should taper off as the system exits the province, though some lingering lake effect flurries may persist near Lake Ontario and along Georgian Bay's southern shoreline into Friday evening.

Given the highly localized nature of snow squalls, snowfall totals will vary significantly over short distances. Areas between Toronto and Burlington are most likely to see accumulations of 10-15 cm, with a slim chance of localized amounts reaching 20-25 cm if conditions align perfectly. That said, such higher totals are likely overestimations, though similar events in the past have exceeded expectations.

Beyond the GTA, snowfall amounts of 5-10 cm are expected in Hamilton, parts of the Niagara Region, and areas like the Dundalk Highlands and Georgian Bay’s southern shoreline, where some enhancement to the system is likely.

Elsewhere in Southwestern Ontario and regions around Lake Simcoe, 2-5 cm is expected, although there is some uncertainty about the system's moisture content, which could lead to slightly higher totals. Windsor, Central Ontario, and Eastern Ontario are expected to receive trace amounts of snow.

Looking ahead to the weekend, a surge of Arctic air will settle over Southern Ontario starting Saturday, with Sunday morning lows dipping well below -20°C across much of the region. In addition to the bitter cold, lake-effect snow is expected to return south of Lake Huron as early as Friday evening, potentially impacting areas like Sarnia, Petrolia, Port Franks, and Grand Bend.

These regions could see localized snowfall totals of 15-30 cm by Saturday. More details on this development will be provided in an upcoming forecast.

December 08, 2024

Prolonged Freezing Rain Threatens Icy Start to Week for Parts of Southern Ontario on Monday

December 08, 2024/ Brennen Perry

December has kicked off with a cold and snowy start across Southern Ontario, as a significant lake-effect snow squall outbreak blanketed parts of the snowbelt over the past week. This wintry weather was accompanied by the season's first blast of Arctic air, bringing wind chills as low as -20°C.

However, a shift in the weather pattern is underway, with milder conditions already spreading into Southwestern Ontario, where Sunday saw daytime highs climbing into the mid to upper single digits.

A weather system is expected to arrive early Monday, bringing warmer air aloft, while near-surface temperatures hover around freezing. This setup creates ideal conditions for freezing rain across parts of Central and Eastern Ontario, which, according to the latest data, could last for an extended period.

Freezing rain is expected to begin in the morning hours on Monday, persisting through the afternoon and into the evening. This prolonged event could result in a thin but hazardous layer of ice forming on untreated surfaces such as roads, sidewalks, trees, and power lines, with localized power outages a possibility.

The initial bands of precipitation will move into Deep Southwestern Ontario, including Windsor and London, during the pre-dawn hours on Monday. Temperatures in this region will remain several degrees above freezing throughout the day, so precipitation here is expected to fall as rain.

As the system progresses north and east during the morning, it will encounter below-freezing temperatures near the surface in areas like the Dundalk Highlands (including Orangeville and Shelburne) and parts of the Greater Toronto Area (GTA).

This will result in the development of freezing rain, creating a zone stretching from Orangeville eastward through York Region, along the higher elevations of the Oak Ridges Moraine, and into southern portions of Central and Eastern Ontario.

This band of freezing rain is expected to persist into the early afternoon, with locations such as Barrie, Orillia, Kawartha Lakes, Peterborough, and Belleville likely experiencing the heaviest impacts.

Further north, areas like Muskoka, Bancroft, and the Ottawa Valley are expected to see a mix of wet snow, ice pellets, and freezing rain beginning early Monday afternoon. While significant snowfall accumulation is not expected for Southern Ontario, enough snow could fall to create slushy and slippery road conditions in these areas.

Freezing rain will begin to taper off in the south later in the afternoon, though freezing drizzle may linger into the early evening. Temperatures are forecast to rise slowly above freezing later in the evening and overnight, which should help melt any accumulated ice, albeit gradually.

In more northern portions of Central and Eastern Ontario, heavier freezing rain will persist into Monday evening before ending overnight. However, freezing drizzle may continue in the Ottawa Valley into early Tuesday morning, potentially causing icy conditions for the Tuesday morning commute.

The most significant freezing rain impacts are expected in a narrow corridor extending around Lake Simcoe and eastward along the Lake Ontario shoreline.

Ice accretion of 2 to 5mm is possible in areas such as Orangeville, Newmarket, Collingwood, Barrie, Orillia, Midland, Bracebridge, Lindsay, Peterborough, Oshawa, Belleville, and Kingston.

For the rest of Central and Eastern Ontario, including the Ottawa Valley, up to 2mm of ice accretion is expected, accompanied by ice pellets and a few centimeters of wet snow.

In the GTA, the greatest impacts from freezing rain will likely occur in the northern and eastern portions of the region. Toronto may experience brief freezing rain during the morning hours, but it is expected to transition quickly to rain, especially closer to the lakeshore.

December 02, 2024

'A Conveyor Belt of Snow’; How Lake Effect Snow Can Bury Entire Towns in a Matter of Days

December 02, 2024/ Alannah Campbell

*satellite image of lake effect snow over the Great Lakes, courtesy of the* *national weather service.*

Following the incredible snowfall seen in Sault Ste. Marie and across parts of Muskoka over the weekend, we figured this would be the perfect opportunity to discuss lake effect snow. It’s something that many of us in Ontario have come to expect in the late fall and early winter, especially since we’re surrounded by the Great Lakes.

Certain ingredients are required for lake effect snow to occur, but most importantly, there needs to be an unfrozen body of water and a very cold air mass from the Arctic.

In order for lake effect snow to even start to form, there needs to be a temperature difference of at least 13°C between the warm surface of the lake and the 850mb pressure level of the atmosphere (this is typically found at around 1500 metres). The greater the temperature difference, the more unstable the atmosphere becomes and this is often when we see strong convection and the phenomenon known as thundersnow. Without this difference in temperature, lake effect snow simply can not occur. Once this threshold is reached, however, it’s like a switch being flipped and the lake effect snow machine starts.

Another key component in lake effect snow development is moisture. Ideally, the relative humidity at the surface needs to be at least 80% for lake effect snow to form and levels below 70% could actually inhibit development. It can usually be assumed that the lake itself can provide enough moisture, but this is not always true. There also needs to be limited wind shear with height between the surface and the 700mb pressure level so that the moisture is more focused, sort of like a hose. The strongest, most organized bands of lake effect snow develop when the wind shear is less than 30°.

Finally is the concept known as “fetch”. Yes, millennials, we’re trying to make fetch happen. Fetch is the distance that the air mass travels over the lake. Fetch needs to be at least 100km in order for lake effect snow to develop and the greater the fetch, the more snow is produced. When considering prevailing wind directions, the traditional snowbelts are found in areas that are downwind of the greatest possible fetch over the Great Lakes, i.e. Buffalo and the entire length of Lake Erie.

The creation of lake Effect Snow. Courtesy of Environment Canada.

When all of these conditions are met, we can see how lake effect snow actually develops.

As the cold air mass travels over the much warmer surface of the lake, the warmth and moisture from the surface is transferred into the lower atmosphere. The warmer, moister air rises and it eventually cools and condenses, forming narrow bands of clouds. These clouds continue to travel over the open lake, gathering even more moisture, until they eventually reach land and the snow starts to fall at rates that can easily exceed 5cm per hour and could even be as high as 20cm per hour! It’s important to note that the hardest hit areas are actually not found immediately at the shoreline, but rather 30-50km inland from the lake.

The direction of the winds dictates which areas are hit by the lake effect snow so as long as the ideal conditions continue, so too will the development and subsequent falling of lake effect snow. This could lead to several days of heavy snow hitting the same area while there are sunny skies less than 20km away. A slight shift in wind direction can quickly change which area gets hit and that makes lake effect snow notoriously tough to forecast.

November 29, 2024

UPDATE: Squalls on Track to Bury Parts of Ontario’s Snowbelt in Up to 100cm of Snow by Saturday

November 29, 2024/ Brennen Perry

Confidence remains high for a very impactful snow squall event, which began east of Georgian Bay and Lake Huron Thursday evening. By the end of Saturday, some parts of the snowbelt region could be digging out of up to 50 to 100cm of snow!

Intense snow squall activity is expected to persist throughout Friday, with two primary squalls forming off Georgian Bay. The southern squall looks to settle between Honey Harbour and MacTier, extending inland toward the Highway 11 corridor from Washago to Bracebridge. This squall may reach as far inland as Haliburton and potentially Bancroft at times.

The second squall is projected to stretch across the northern tip of the Bruce Peninsula, coming onshore near Parry Sound. Unlike the southern squall, this one may not push as far inland, meaning Huntsville could see lighter impacts compared to areas like Bracebridge and Gravenhurst.

Snow squalls will also persist east of Lake Huron, with the most significant activity setting up just south of Hanover. Higher totals inland can be attributed to colder temperatures in elevated areas, where snow will accumulate more efficiently, compared to the slightly above-freezing conditions closer to the shoreline.

As Friday progresses, models suggest a brief wind shift by the evening, potentially driving the Georgian Bay squall south of Muskoka and into parts of northern Simcoe County.

There is some uncertainty about how far south this squall will drift, but most models suggest it will impact Midland, areas just north of Orillia, and into Rama. Within Orillia, accumulation could vary significantly, with lower totals in the south and much higher amounts in the north, reflecting the sharp gradient shown on our map.

By Saturday morning, the squall is expected to shift back north, realigning across the Parry Sound and Muskoka region. However, this time, it may consolidate into a singular band stretching from Parry Sound into northern Muskoka. This could spare Gravenhurst and Bracebridge from heavy snowfall on a second day, while Huntsville might see more snow as the squall locks into place for much of Saturday.

IMPORTANT

To provide the most accurate information, we are now breaking the snowfall totals into two separate forecasts. This forecast covers Friday and Saturday, while a second forecast will address Sunday and Monday and will be released on Saturday.

Our earlier forecast covered the entire four-day period and was intentionally broad to account for a wide range of possibilities. If the snowfall totals for your area are lower than what we initially predicted, it’s likely because your snow will fall later on Sunday or Monday.

As we’ve emphasized in previous updates, snow squalls are notoriously difficult to predict, with sharp gradients between areas of light snow and those with extreme accumulations.

In terms of snowfall totals, localized amounts are likely to exceed 50 cm and may even approach 100 cm by the end of Saturday in areas like Parry Sound, Bracebridge, and Gravenhurst. Similar totals are possible for Tobermory and Hanover.

Owen Sound and Collingwood could also experience heavy snow from a Lake Huron streamer, with higher elevations aiding accumulation. These areas could see snowfall ranging from 25 to 50 cm in the most affected zones.

Given the tight gradients, snowfall totals will decrease quickly as you move away from the primary snow squalls. Expect 15 to 30 cm across much of Grey-Bruce counties, northern Simcoe County, northern Kawartha Lakes, and Haliburton (excluding the heaviest-hit areas mentioned earlier).

For the rest of Southern Ontario, less than 5 cm is expected by the end of Saturday. However, regions like Barrie, Kitchener-Waterloo, and London could see some snowfall accumulation on Sunday and Monday as the winds shift late Saturday. So, if you’re hoping for snow in those areas, don’t give up yet!

Stay tuned for more updates, including our next detailed forecast on Saturday!

November 20, 2024

Season’s First Snowfall Possible for Wide Swath of Southern Ontario Starting Late Wednesday

November 20, 2024/ Brennen Perry

Over the past week, calm conditions have dominated the weather story across Southern Ontario. This pattern has also brought a return to more seasonal temperatures typical for this time of year, a noticeable shift from the unseasonably warm weather that lingered into early November.

One notable absence so far this season is snow—a staple of November in Southern Ontario. While some regions, especially higher elevations in Central Ontario, the Ottawa Valley, and the Dundalk Highlands, experienced their first flurries as early as September and October, much of Southern Ontario has yet to see its first snowfall.

That, however, could soon change with the arrival of multiple weather systems in the coming days, bringing colder air and the potential for wet flurries as early as Wednesday evening and into Thursday and Friday.

The good news for those not yet ready to embrace winter is that significant accumulation isn’t expected with this initial blast of wintry weather. Temperatures are forecast to hover just above freezing, which will likely limit accumulation as any snow melts upon contact with the wet and relatively warm ground left behind by earlier rainfall.

In addition to the season’s first flurries, a slow-moving system will stall over the Great Lakes region, pulling in moisture from another system over New England. This setup will lead to ample precipitation, with heavy rain expected to persist into the start of the weekend. Eastern Ontario is poised to bear the brunt of this rainfall, with totals ranging from 25 to 50 mm between Wednesday and Saturday.

**SIMULATED RADAR** - MAP FROM WEATHERBELL

The rain is expected to begin on Wednesday afternoon, with the initial band of heavy rain arriving in Deep Southwestern Ontario and areas near the Lake Erie shoreline by dinnertime.

This line of precipitation may also bring embedded, non-severe thunderstorms and wind gusts of 70-80 km/h. While most gusts are expected to remain below the severe threshold, isolated gusts near 90 km/h are possible, particularly over the Niagara region during the early evening hours.

As this line of rain races across Southwestern Ontario and into the Golden Horseshoe, colder air will begin rushing in from the west. However, there is some disagreement among models regarding how quickly temperatures will drop and how rapidly the precipitation will move. Some projections suggest a sharp cooldown, with temperatures in Southwestern Ontario nearing freezing by Wednesday evening.

If this happens, rain could transition to wet snow in areas such as Sarnia, London, Goderich, Kitchener, Guelph, and Orangeville. However, with earlier rainfall and temperatures still above freezing, any snow is likely to melt on contact. Elevated areas northwest of the GTA, particularly the Dundalk Highlands, may see light accumulation of up to 2-4 cm overnight into Thursday morning.

By Thursday morning, most of the moisture will shift into Central and Eastern Ontario, with the centre of the low-pressure system stalled over Lake Huron. Meanwhile, a secondary system over New England will provide additional moisture, enhancing precipitation over Eastern Ontario throughout the day.

Temperatures in parts of Eastern Ontario, particularly southwest of Ottawa and in higher elevations, will hover near the freezing mark, creating a chance for wet flurries. Closer to the international border extending into the Ottawa region, heavy rain will likely continue.

Precipitation is expected to persist overnight Thursday and linger into Friday, with the heaviest rain focused on Eastern Ontario. In Central and Southwestern Ontario, lingering showers are possible Friday morning and afternoon, though they won’t be as intense as in the east.

For rainfall totals, Eastern Ontario, including Kingston and Ottawa, can expect 25 to 50 mm by Saturday. The rest of Southern Ontario will likely see 10 to 25 mm, though isolated pockets could receive closer to 30-40 mm during thunderstorm activity.

Higher elevations in Eastern Ontario, particularly near Bancroft, may see persistent snow showers that could result in minor accumulation of up to 2-5 cm by Friday morning. However, with temperatures so close to freezing, it’s uncertain how much snow will stick.

Looking ahead to the weekend, there’s good news for those not ready for snow. Earlier model predictions suggested a significant cooldown that could trigger lake-effect snow. However, the latest data indicates the cooldown won’t be as intense as initially thought.

While some lake-effect showers are still possible along the Lake Huron shoreline and southeast of Georgian Bay on Saturday, it likely won’t be cold enough for those showers to fall as snow.

November 05, 2024

What's in a Name? Choosing the Right Tires to Drive you Through Canadian Winters

November 05, 2024/ Alannah Campbell

*Tread patterns of summer, all season and winter tires. Image courtesy of* *discount tire*.

Now that it’s the first week of November, many Canadians are starting to think about putting winter tires on their vehicles. There have been pockets of unseasonable warmth across the country in October and the start of November, the inevitable chill of winter is in the air, and many have already seen snow fall.

While winter tires are recommended throughout the country, they are mandatory in Quebec from December 1st to March 15th, and from October 1st to April 30th on certain British Columbia highways. Additionally, studded tires are allowed almost nationwide, with the exception of residents of Southern Ontario.

Insurance companies across the country offer discounts for installing winter tires as an incentive to encourage drivers to reduce the risk of accidents. So what makes winter tires that much better in the cold and snow than summer tires and where do all season and all weather tires fit into the mix?

*With the right tools, it can be pretty easy to change your own tires!*

Summer Tires

Summer tires are designed to handle both wet and dry road conditions with their wide tread and soft rubber. These tires also usually have deeper grooves that improve traction on wet roads and reduce hydroplaning, making them ideal for the wet spring and summer months.

Winter Tires

Like their name suggests, winter tires have been designed for winter roads. They are made with rubber that stays flexible at temperatures below 7°C (45°F), the magic number at which other tires become stiff and lose traction, greatly reducing their performance. Furthermore, winter tires have different tread patterns that are meant to divert water and slush to the sides, as well as little slits called sipes that increase the overall grip of the tires and helping them maintain contact with icy road surfaces. Over the past several years, tire manufacturers have started to include additional small particles, like crushed glass or walnut shells, that act as little studs on the surface of the tire for extra grip.

All Season & All Weather Tires

Some people argue that winter tires aren’t necessary if they have all season tires on their vehicle. Unfortunately, this is a slight misnomer because while these tires can handle a bit of cold and snow, they fail to handle heavier snowfalls that are common in Canadian winters. All season tires, unfortunately, sacrifice traction in wet conditions that would be found in summer tires and some of the flexibility and grip seen with winter tires in order for the tread to last longer. Realistically, these should be called 3 season tires as opposed to all season. So while they’re not the best option for winter driving in Canada, all season tires are definitely a better choice than regular summer tires.

All weather tires, not to be confused with all season tires, are a true year-round tire designed to handle Canadian winters. Unlike all season tires, these tires remain soft and flexible well below 7°C. The tread pattern on all weather tires is a combination of all season and winter tires, making them better suited for driving through heavier snow than all season tires. While they still don’t match the performance of a true winter tire, all weather tires are the best option for those who don’t want the hassle of swapping out their tires twice per year or simply do not have the space to store an extra set. Their versatility truly makes all weather tires a middle of the road tire (pun intended) for Canadian drivers.

*The three-peak mountain snowflake symbol found on winter and all weather tires. Image courtesy of* *Canadian tire*.

When looking for tires to get you through the winter, it is recommended to chose either a proper winter tire or an all weather tire, so long as it has the three-peak mountain and snowflake symbol on the sidewall. This is an industry standard symbol which indicates that the tire meets strict regulations for winter performance; becoming mandatory on all winter tires beginning in 2018, transitioning away from just using the M+S (Mud and Snow) designation.

Further Reading

https://www.canadiantire.ca/en/how-to/automotive/how-to-choose-winter-tires.html

https://www.continental-tires.com/ca/en/tire-knowledge/winter-tire-laws-in-canada/

https://www.continental-tires.com/ca/en/tire-knowledge/winter-tire-markings/

https://www.discounttire.com/learn/tires-below-45

https://www.discounttire.com/learn/winter-summer-allseason

Note: The author formerly received payments from “Big Tire” however, this article was not funded.

October 26, 2024

Spooky Snow May Make an Appearance in Parts of Ontario to Kick Off Halloween Week

October 26, 2024/ Brennen Perry

The month of October has mostly brought calm and mild conditions to Ontario, with temperatures occasionally climbing above seasonal averages and minimal precipitation. But as we approach the final days leading up to Halloween, colder air is making a return, setting the stage for a possible wintry “trick” in parts of the region.

This past week, temperatures in some areas reached the upper teens and even low 20s, but now a noticeable chill has settled in. Many spots across Southern and Northern Ontario are already experiencing single-digit highs as the warm air retreats.

As the weekend progresses, the cold will only deepen, with Sunday morning expected to bring temperatures near or just below freezing across the province. Afternoon highs will provide little relief, as most places in Central and Eastern Ontario will likely struggle to rise out of the single digits.

A Weak Weather System and a Chance of Snow

**PRECIPITATION TYPE FOR SUNDAY EVENING** - MAP FROM WEATHERBELL

On Sunday, a weak weather system will begin to make its way into Northeastern Ontario and eventually move toward Central Ontario by the afternoon. This will likely bring some light rain showers to areas like Sault Ste. Marie, Sudbury, North Bay, and Muskoka. As colder air continues to push southward after sunset, temperatures will drop quickly, setting the stage for a possible transition from rain to wet snow in the evening.

While surface temperatures are expected to stay just above freezing until after midnight, colder air moving in aloft may allow the rain to change to snow as the night progresses. Precipitation will gradually spread southeastward, reaching Bancroft, Kingston, and possibly the Ottawa area.

There is some uncertainty about whether Ottawa itself will see any snowflakes, as models suggest that a dry air pocket may limit snowfall, keeping the bulk of moisture just to the south.

Potential for Accumulation and a Hard Freeze

**ESTIMATED MINIMUM TEMPERATURE ON MONDAY MORNING** - MAP FROM WEATHERBELL

Temperatures will continue to drop overnight, leading to what is referred to as a “hard freeze” in areas like Sudbury, North Bay, Algonquin Park, and the Ottawa Valley. During a hard freeze, temperatures remain several degrees below freezing for extended periods, which could kill sensitive plants.

The drop in temperature may also allow for some light snow accumulation, with a dusting of 2-3 cm possible by Monday morning in some areas. Though not a significant amount, it could be enough to create slippery conditions on roads, making for a potentially slow and hazardous Monday morning commute.

Light flurries may linger across parts of Central and Eastern Ontario into late Monday morning, gradually tapering off around noon. With temperatures hovering close to the freezing mark throughout the day, any snow that does manage to accumulate will likely melt slowly. Motorists should remain cautious, as wet or slushy conditions could persist longer than usual.

Midweek Warm-Up on the Horizon

**ESTIMATED DAYTIME HIGH TEMPERATURE ON WEDNESDAY** - MAP FROM WEATHERBELL

For those hoping for a break from the cold, a warm-up is expected by midweek. By Tuesday, daytime highs in parts of Southwestern Ontario could rebound into the low to mid-20s, with the warmer air spreading to Central and Eastern Ontario by Wednesday.

However, the return of milder weather may be accompanied by some wet conditions. A fast-moving weather system is forecast to pass through Southern Ontario on Tuesday, bringing the potential for 15-30 mm of rainfall across Central and Eastern Ontario between late Tuesday and Wednesday.

While the exact track remains uncertain, some models suggest the rain may shift further north, potentially impacting the area differently than initially expected.

What’s in Store for Halloween?

**ESTIMATED TEMPERATURE FOR HALLOWEEN AT 8 PM** - MAP FROM WEATHERBELL

With Halloween fast approaching, many Ontarians are wondering what the weather will be like for Trick-or-Treating. As of now, forecasts indicate a chance of widespread rain across much of Southern Ontario during the afternoon, possibly lingering into the evening. Afternoon temperatures are expected to start in the mid to upper teens, but a cooling trend may bring them down to the low teens or even upper single digits by the time Trick-or-Treaters hit the streets.

There is still some disagreement among models regarding the exact timing of the rain. While it seems the heaviest precipitation may fall earlier in the day, there is a chance that skies could clear in time for the evening festivities, especially in Southwestern Ontario. Meanwhile, Eastern Ontario may be among the last regions to see any potential clearing.

Stay tuned as more details emerge in the days leading up to Halloween, and be prepared for whatever weather “tricks” or “treats” may come your way!

September 06, 2024

Snowy Surprise: Parts of Ontario & Quebec Could See Season’s First Snowflakes This Weekend

September 06, 2024/ Brennen Perry

As we enter the first full weekend of meteorological fall, Mother Nature is set to deliver a taste of autumn across Ontario and Quebec. A brief blast of cold air will cause temperatures to drop near the freezing mark during the pre-dawn hours on Saturday and Sunday.

Precipitation currently affecting Southern Ontario is expected to linger throughout the weekend. The heaviest rainfall totals are expected overnight Friday into early Saturday in Eastern Ontario, with localized amounts of 20-40 mm of rain possible.

The bigger story is when that precipitation wraps around into Western Quebec and Northeastern Ontario later on Saturday, continuing into the early morning hours of Sunday. With temperatures cooling into the low single digits and even colder air aloft, some of that precipitation may fall as wet snow.

It appears that locations like Timmins, Cochrane, Kirkland Lake, Temiskaming Shores, Deep River, and Algonquin Park in Ontario could see their first snowflakes of the season. In Quebec, areas such as Ville-Marie, Rouyn-Noranda, Amos, and Val-d'Or may also experience wet snow.

While it's unlikely that snow will accumulate, as it will be mixed with rain and ground surfaces are still too warm, there's a chance that colder-than-expected conditions could lead to a few slushy centimetres in some areas. Any accumulation will melt quickly after sunrise on Sunday as temperatures gradually rise.

Speaking of Sunday morning, this is when the coldest air of this brief "cold snap" is expected across Ontario and Quebec. Morning lows will likely drop into the single digits across much of Northern and Southern Ontario and Quebec. In Northeastern Ontario and the Algonquin Park region, temperatures could dip to near freezing during the pre-dawn hours, increasing the risk of frost in addition to the potential for wet snow.

Further south, the coldest temperatures in Southern Ontario will be in the higher elevations of Central Ontario, east of Muskoka, where temperatures may plunge to around 2-5°C. It will be moderately warmer in Southwestern Ontario, the Golden Horseshoe, and Eastern Ontario, with morning lows ranging from 5-10°C. Those along the shorelines of Lake Ontario, Lake Erie, Lake Huron, and Georgian Bay will benefit from the warmer lake waters, keeping temperatures above 10°C.

In Quebec, expect low to mid-single-digit temperatures in the western portion of the province near the Ontario border on Sunday morning. Eastern Quebec, including Montréal and Québec City, will see lows in the upper single digits, ranging from 6-12°C.

WATERSPOUT RISK FOR GREAT LAKES ON SATURDAY MORNING (SORUCE: ICWR)

This cold air will also contribute to a potential waterspout outbreak over the Great Lakes this weekend. The highest risk is on Saturday, especially in the morning and afternoon, with a focus on Southern Lake Huron and Western Lake Erie. Waterspouts are also possible over Southern Georgian Bay, Western Lake Ontario, and even Lake Simcoe.

While waterspouts rarely threaten land, they can be hazardous for those on the water. In rare cases, waterspouts can come ashore, causing minor damage along the immediate shoreline.

The waterspout risk will persist into Sunday, with a focus on Eastern Lake Ontario.

Looking ahead to next week, warmer weather is expected to return to Ontario and Quebec. By late in the week, temperatures could climb back near the 30°C mark in Southern Ontario. So, while this brief taste of fall may be shocking, it looks like summer isn't quite finished yet.

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