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 09, 2025

Widespread Snowfall to End the Week Across Southern Ontario on Friday; Up to 5-10cm Possible

January 09, 2025/ Brennen Perry

While 2025 began with heavy snow across parts of Southern Ontario, most of the activity so far has been confined to traditional snowbelt regions. That’s about to change, as a new system is set to bring the first widespread snowfall of the year to much of Southern Ontario starting Friday.

Most of Southwestern, Central, and Eastern Ontario can expect snowfall totals of 5 to 10 cm between Friday afternoon and Saturday morning. However, areas along the Lake Huron shoreline and into the Bruce Peninsula may see enhanced snowfall, with totals reaching 10 to 20 cm due to lake-effect activity and embedded snow squalls.

As the system moves out, additional snowfall is likely over the weekend. Lake-effect snow squalls developing southeast of Lake Huron and Georgian Bay could bring localized accumulations of 20 to 30 cm from Saturday afternoon into Sunday.

SNOWFALL TIMING

**PRECIPITATION TYPE** - MAP FROM WEATHERBELL

The system-related snowfall will begin spreading into Southwestern Ontario late Friday afternoon, with regions near Lake Huron, including Deep Southwestern Ontario, seeing snow first.

Through the dinner hours, the snow will advance northeast, gradually reaching the Golden Horseshoe and portions of Central Ontario by Friday evening. By midnight, snow will cover most of Southern Ontario, extending into Eastern Ontario.

The most intense period of snowfall is expected overnight Friday into early Saturday morning. While the snow will generally be light, it could lead to several hours of steady accumulation, potentially impacting travel.

Exercise caution if you plan to drive during this time, and remember to adjust your speed to match road conditions.

For areas along the Lake Huron shoreline and into the Bruce Peninsula, lake-enhanced snowfall could intensify during the evening and overnight hours on Friday, resulting in heavier accumulations compared to surrounding areas.

Snowfall from this system will taper off from west to east starting early Saturday morning in Southwestern Ontario, with Eastern Ontario holding onto snow until late morning.

Flurries may linger into Saturday afternoon, especially in some regions.

As the system exits, lake-effect snow squalls may develop off Lake Huron and Georgian Bay by Saturday afternoon. Forecast models currently show some uncertainty about how organized these squalls will be and whether they will lock into specific areas for prolonged periods.

Higher-resolution models are just coming into range, so a detailed forecast for snow squall activity will be issued on Friday.

HOW MUCH SNOW TO EXPECT

In terms of totals, most of Southern Ontario will see 4 to 8 cm of snowfall, with slightly higher amounts of up to 10 cm possible in localized areas. This includes the east end of the Greater Toronto Area (GTA), such as Oshawa, and parts of Southwestern Ontario due to minor lake enhancement from Lake Ontario and Lake Huron.

The Golden Horseshoe and Ottawa Valley are expected to see slightly lower snowfall amounts, closer to 3 to 6 cm.

A zone along the Lake Huron shoreline—including Grand Bend, Goderich, Kincardine, and the Bruce Peninsula—could see locally higher accumulations by Sunday afternoon. Current estimates suggest 10 to 15 cm for these areas, with up to 20 cm possible for the Bruce Peninsula.

WEEKEND SNOW SQUALL PREVIEW

Environment Canada has identified areas near Barrie, Goderich, and London as hotspots for the most intense snow squalls over the weekend.

Here’s Environment Canada’s weekend outlook:

Saturday, January 11, 2025: “Lake effect snow squalls off Lake Huron and Georgian Bay are expected to develop Saturday afternoon. Local snowfall amounts of 10 to 15 cm are possible along with reduced visibility in heavy snow.”
Sunday, January 12, 2025: “Lake effect snow squalls off Lake Huron and Georgian Bay are expected to continue on Sunday. Local snowfall amounts of 10 to 15 cm are possible along with reduced visibility in heavy snow.”

As always, stay tuned for updates, especially if you’re in areas likely to experience lake-effect snow. Stay safe, and plan ahead for winter driving conditions!

January 07, 2025

Retrograding Storm Returns to the Maritimes, Bringing Up to an Additional 30cm of Snow

January 07, 2025/ Alannah Campbell

It seems as though the storm from the weekend isn’t quite finished with the Maritimes. There have been scattered flurries across the region throughout the day Tuesday, but more organized bands of snow are on their way.

The snow will move into Northern New Brunswick from the north early Wednesday morning and spread southward into the region. By sunrise, the snow will reach Prince County, PEI and then Northern Nova Scotia by the early afternoon. This band of snow will last for up to 12 hours, but the snow will be light and come in bursts, resulting in up to 5cm of accumulation.

In the late afternoon and early evening, a second band of snow will push southward into Northern New Brunswick and following the same path as the first. This round will bring another 12 hours of steady snow across the region before starting to dissipate early Thursday morning. There will be pockets of heavier snow in this second wave, which will drive snowfall totals above 10cm in some parts of the Maritimes.

The snow will taper off throughout Thursday morning, but in the late morning to early afternoon, one final round of precipitation will move in. This third and final round will arrive after temperatures climb above freezing, resulting in mostly rain falling, but a bit of snow mixed in, across the Maritimes Thursday afternoon and into early Friday morning.

From these three rounds of precipitation, we’re looking at widespread snowfall totals of 5-20cm across the Maritimes. There will be areas where the snow will persist into late Thursday morning from the second round of snow, particularly the Annapolis Valley and at higher elevations in Northern New Brunswick. There will also be areas where more snow than rain will fall in the third round, namely the Northumerland Shore and the Cape Breton Highlands. The Highlands will see the most snow, up to 30cm, due to steady and often heavy snowfall over the duration of this event.

January 07, 2025

Mid-Week Squalls Could Dump Up to 25-50cm of Snow to Parts of Southwestern Ontario by Thursday

January 07, 2025/ Brennen Perry

The New Year has certainly started on a frigid note across Ontario, as Arctic air has firmly settled over the region in recent days. These cold temperatures, combined with open lakes, have created the perfect conditions for lake-effect snow. Late last week and into the weekend, parts of the province experienced significant snowfall, with totals southeast of Georgian Bay reaching or exceeding 50 cm.

Over the past 24 hours, the lake-effect machine has largely taken a break, aside from some minor activity south of Lake Huron and Georgian Bay. However, that respite will be short-lived. Beginning Tuesday evening, snow squalls are expected to return with a vengeance as wind directions realign and even colder air moves into the region. These squalls are anticipated to persist through Wednesday and into early Thursday before tapering off.

This round of lake-effect snow will likely target areas that were largely spared during the last event. The focus this time will be on regions southeast of Lake Huron and along the southern shoreline of Georgian Bay. Some of the hardest-hit areas could include London and Collingwood, with snowfall totals potentially ranging from 25 to 50 cm over the next 48 hours.

As for the timing, models differ slightly on the intensity and precise placement of the squalls. The latest data suggests snow squalls could begin organizing as early as Tuesday evening. The squall off Georgian Bay is expected to impact the Collingwood and Blue Mountain area, stretching inland toward Creemore, Alliston, and Shelburne. It may also affect the Highway 400 corridor just south of Barrie.

Meanwhile, activity off Lake Huron could produce multiple squalls developing between Kincardine and Grand Bend, with bands extending inland in a southeasterly direction. This puts portions of Huron, Perth, and Middlesex counties in the crosshairs.

The Georgian Bay squall appears to be somewhat weaker than its Lake Huron counterpart, likely due to the smaller lake surface area supplying moisture. That said, it is expected to remain relatively stationary through the overnight hours into Wednesday, resulting in steady snowfall accumulation and reduced visibility.

Travel in this area will likely be challenging from Tuesday night into Wednesday, with little improvement expected until the activity begins to subside overnight.

Lake Huron squalls, on the other hand, are expected to shift around more frequently, spreading out snowfall accumulations. By Wednesday morning, the primary squall is forecasted to come ashore around Grand Bend, extending inland toward Lucan, Strathroy, and London.

There is still some uncertainty about whether the squall will directly impact the City of London or remain just northwest. Western parts of the city are likely to see the heaviest snowfall, while eastern areas may receive lighter accumulations.

Scattered snow squalls east of Lake Huron are expected to continue affecting Huron and Perth counties throughout Wednesday. These squalls may vary in intensity, and if one becomes particularly organized and stalls over an area, rapid snowfall accumulation could occur.

The most intense conditions are expected during the day on Wednesday, extending into the evening and overnight hours.

By midnight, the lake-effect activity is expected to become more localized. The Georgian Bay squall will likely retreat closer to the shoreline, while the Lake Huron squalls may consolidate into a narrower band near Grand Bend, extending into the London area.

While this will reduce the overall impact, areas caught under these more focused squalls could experience increased snowfall rates for several hours overnight into early Thursday morning.

By pre-dawn Thursday, the lake-effect activity is anticipated to taper off, with the Georgian Bay squall dissipating before sunrise and the Lake Huron squall following a few hours later.

Snowfall totals from this round of snow squalls will vary widely, as is typical with these events. This forecast is particularly tricky due to discrepancies in model data regarding the intensity of the snow bands, which will significantly affect accumulation.

Based on the current environment and dynamics, there is potential for 25 to 50 cm of snow in areas such as London, Lucan, Grand Bend, Clinton, and Collingwood. However, these totals are not guaranteed, as exact amounts will depend on where the bands set up.

For London, in particular, snowfall accumulations will likely be heavier in the northwest, while eastern areas may only see totals between 10 and 25 cm.

Surrounding areas like Goderich, Point Clark, Mitchell, Strathroy, and St. Thomas could see localized accumulations of 15 to 25 cm, depending on the positioning of the bands. Similarly, areas southwest of Barrie, including Angus, Alliston, and Beeton, may receive 10 to 20 cm as the Georgian Bay squall extends inland.

Outside these regions, significant snowfall is not expected due to the highly localized nature of lake-effect activity. However, portions of Eastern Ontario near the U.S. border and areas east of Ottawa may see 5 to 10 cm of accumulation on Wednesday due to a separate system lingering over Quebec.

January 04, 2025

First Major Winter Storm of the Year is Taking Aim at Cape Breton Island With Over 50cm of Snow Possible

January 04, 2025/ Alannah Campbell

The new year is starting off with a bang in parts of the Maritimes with the arrival of a major winter storm. While Newfoundland will feel the brunt of the storm, Eastern Nova Scotia and Prince Edward Island can expect a significant amount of snow and strong winds throughout the day Sunday and into Monday. The rest of the Maritimes, meanwhile, will experience little to no impacts from the storm.

The storm has been rapidly intensifying during its approach towards Atlantic Canada throughout the day Saturday, meeting the criteria of a bomb cyclone (a drop in internal pressure of at least 24mb in 24 hours).

The western edge of the storm will briefly skim along the far eastern coast of Cape Breton Island early Sunday morning as the storm surges north towards Newfoundland, bringing snow and wind gusts of 70-90km/h. The storm will continue to grow in size as it gains latitude, which will push the snowfall and intense winds deeper into Cape Breton as the morning progresses.

By the mid-morning, the storm is expected to shift and start moving along a more northwesterly track, which will bring the snow and strong winds into Eastern Mainland Nova Scotia, across Prince Edward Island, and briefly to the eastern tip of the Acadian Peninsula. Blowing snow will greatly reduce visibility across the area throughout the day and could even lead to blizzard conditions.

The storm will gradually lose momentum later in the afternoon before completely stalling for several hours in the late evening and overnight. This will result in the impacted areas of PEI and Nova Scotia seeing snow quickly accumulate and the strong winds continuing while also limiting how far westward into the rest of the Maritimes that the snow spreads.

***Model run showing Snow (Blue) and Rain (green) at 11pM on Sunday, January 5th***

At around sunrise on Monday morning, the storm will start to fall apart, with the snow tapering off and the winds dying down across PEI and Mainland Nova Scotia throughout the morning. By the early afternoon, the only snow falling will be in the Cape Breton Highlands, where it will continue until the late evening.

The Cape Breton Highlands will be the hardest hit area and heavy snow is expected to fall for 24 hours at up to 5cm/hr, leading to over 50cm of accumulation here. This area will also see the strongest wind gusts from the storm, up to 100km/h, making travel very treacherous and possibly resulting in power outages.

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 03, 2025

A Brief Skiff of Snow Expected Across Parts of Southern Alberta & Saskatchewan for the First Weekend of the New Year

January 03, 2025/ Alannah Campbell

It’s been fairly quiet across the Prairies for the past few weeks and that trend has continued so far in the beginning of the new year. As we approach the first weekend of the year, there’s enough snow expected for parts of Southern Alberta and Saskatchewan over the next 24 hours to warrant a forecast.

The snow will begin to fall along the American border in Alberta early this evening and it will gradually spread north and eastward overnight and early Saturday morning. It is only going to reach as far north as Calgary and into Southwest Saskatchewan before the system starts to fall apart before sunrise Saturday morning. The snow will gradually taper off throughout the morning and into the early afternoon.

The snow is expected to be light throughout the duration of the event, leading to most of the area receiving 5-10cm of accumulation. As the system falls apart Saturday morning, the snow is expected to linger over parts of Southeast Alberta and Southwest Saskatchewan, resulting in over 10cm of snowfall here.

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.

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 23, 2024

One Last Pre-Holiday Blast of Winter Could Make Travel Difficult in the Maritimes with up to 30cm of Snow

December 23, 2024/ Alannah Campbell

There’s more snow on the way for the Maritimes following the storm over the weekend. The next system that will hit tomorrow, Christmas Eve, and continue into Christmas morning, will once again negatively impact the holiday travel plans for many across the region.

New Brunswick

The snow will start to push into Western New Brunswick around midnight tonight and spread eastward across the province before sunrise tomorrow. By that point, the snow will already have tapered of in the Northwest, leading to less than 5cm of accumulation in this area. As we progress through the morning, the snow will start to gradually diminish across western parts of Northern and Central New Brunswick as the system tracks southeastward.

Meanwhile, a bit of intensification is expected, leading to much of the province receiving over 10cm of snow by the end of the day. Pockets of particularly heavy snow are likely through the afternoon along the Fundy Coast, with the snow falling at up to 5cm/hr. This is expected to bring snowfall totals to over 20cm for this area, including Saint John, and over 30cm locally in areas of higher elevation.

The system will continue tracking southeastward across the province throughout the afternoon and early evening, at which time the entire system starts to fall apart. This will lead to scattered flurries lingering overnight and the early morning in Southeast New Brunswick.

Prince Edward Island

The snow will start in PEI a couple of hours before sunrise in Prince County, spreading across the rest of the Island throughout the morning and into the early afternoon. By the time the snow reaches the eastern edge of Kings County in the mid to late afternoon, this area will see snowfall for only a few hours before the system starts to break down. As a result, this area can expect less than 5cm of snow while the rest of the Island will receive upwards of 10cm.

There could be some lingering flurries for PEI overnight and into Christmas morning, but these will only add on another centimetre or two to the final snowfall totals.

***Model run showing Snow (Blue) and Rain (green) at 4pM on Tuesday December 24th***

Nova Scotia

The snow will make its way into both Northern and Western Nova Scotia from the northwest starting in the early morning before sunrise. It will push deeper across the province through the morning and early afternoon, but it is not expected to cross very far into Cape Breton, if at all. Isolated flurries can’t be completely ruled out here so our forecast is for up to 2cm of snow for this area.

The temperatures will rise throughout the day with the arrival of the storm and will climb above freezing in parts of Western Nova Scotia. Those living inland will see temperatures of 1°C, resulting in the buildup of heavier, wet snow. On the other hand, coastal communities in Yarmouth, Shelburne, and Queens Counties are expected to get up to 3°C and the snow will transition to rain, limiting overall snowfall totals to 5-10cm.

In the evening, the system will fall apart, leading to pockets of precipitation occurring across the Mainland for a few hours. Later into the evening and overnight, the snow is expected to persist over Western Nova Scotia and with temperatures remaining a degree or two above freezing, the snow that falls will be very wet and mixed with some rain. This will bring snowfall totals closer to 20cm and locally higher for parts of the Annapolis Valley.

This system is unfortunately very ill-timed and will really impact the plans that many people have to travel and visit family over the next couple of days. Thankfully, most of the snow will be finished by Christmas morning so day-of holiday travel shouldn’t be too tough.

Wind gusts should top out at about 50km/h on Tuesday, with the strongest gusts expected in Southern New Brunswick and Western Nova Scotia so visibility could be limited at times with brief whiteouts, but we won’t be at risk for full blizzard-like conditions.

Since the chances for a White Christmas across the Maritimes seem fairly obvious at this point, with Guysborough County and Southern Cape Breton just hitting the 2cm threshold along with the arrival of even more snow on Christmas Eve, we will not be updating our preliminary White Christmas Forecast. Enjoy your White Christmas everyone!

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 20, 2024

Pre-Christmas Squalls Could Bring Up to 25-50cm of Snow on Saturday to Parts of Southwestern Ontario

December 20, 2024/ Brennen Perry

As we approach the final weekend before Christmas, Southern Ontario is gearing up for the coldest air of the season so far. With the lakes still unfrozen after the unseasonably mild fall, conditions are setting up perfectly for the lake effect snow machine to roar back to life, particularly off Lake Huron.

Lake effect snow squalls are expected to develop as early as Friday evening along the southern shoreline of Lake Huron and persist through much of Saturday. Current indications suggest the heaviest snowfall will target the corridor between Sarnia and Strathroy. By the time the squalls taper off late Saturday, some areas could be buried under 25 to 50 cm of fresh snow.

This snowfall is promising news for those hoping for a White Christmas. With below-freezing temperatures expected to last through Tuesday, the snow should be deep enough to hold on despite a brief warm-up on Christmas Eve into Christmas Day when temperatures may climb above freezing.

Based on the latest data, a fairly intense snow squall is anticipated to form around midnight, likely affecting areas between Petrolia and Strathroy. However, the exact location of this band remains uncertain and will determine which areas see the most significant snow. The best bet at this time places the heaviest snow over Port Franks, Lambton Shores, and Kettle Point.

The squall is expected to persist through the overnight hours into early Saturday morning, bringing dangerous travel conditions in the affected regions. Rapidly accumulating snow combined with near-zero visibility will likely lead to road and highway closures. There’s also potential for the squall to extend further inland, possibly reaching areas northeast of Chatham along the Lake Erie shoreline.

Meanwhile, locations along the eastern shoreline of Lake Huron, from Kincardine to Grand Bend, may experience occasional bursts of heavy snow as the squall shifts and clips the shoreline.

By late Saturday morning and into the afternoon, the lake effect activity south of Lake Huron is expected to weaken as the band becomes more spread out and less organized. The squall should gradually diminish and retreat closer to the shoreline by Saturday evening, eventually fizzling out overnight into early Sunday morning.

In addition to the Lake Huron squalls, minor lake effect activity is possible south of Georgian Bay, including areas like Owen Sound, Meaford, and Collingwood. However, this activity is not expected to be as intense, with light to moderate snowfall likely throughout the day on Saturday.

When it comes to snowfall accumulation, variability is the nature of lake effect events. Narrow squalls can lock into a region and dump significant snow over a small area while sparing nearby locations.

We currently expect areas including Warwick, Watford, Forest, and Lambton Shores to receive between 25 to 50 cm of snow by the end of Saturday, with localized totals possibly exceeding 50 cm in some spots, although this is likely an overestimate.

The gradient will be sharp, with Petrolia and Grand Bend potentially seeing 15 to 25 cm. Sarnia and Strathroy, on the outskirts of the main activity, are likely to receive just 2 to 5 cm, although even a slight shift in the squall’s position could put these areas into the heavier snow zone.

Further up the eastern Lake Huron shoreline, locations from Kincardine to Grand Bend could see 5 to 15 cm of snow, with most areas leaning toward the lower end of that range.

South of Georgian Bay, including Owen Sound, Meaford, and Collingwood, snowfall is expected to range between 2 to 5 cm, with localized amounts up to 10 cm possible if the activity becomes more organized.

Elsewhere, the Niagara Region could pick up 2 to 5 cm of snow overnight into early Saturday morning as lingering precipitation from a previous system continues.

For the rest of Southern Ontario, no significant snowfall is expected this weekend. However, we are closely monitoring a potential snowmaker early next week between Monday and Tuesday, which has been trending stronger in recent model data. This system could bring heavy snow to parts of Southern Ontario, maybe sealing the deal on a White Christmas for many. We’ll provide more details on that in a separate forecast.

December 20, 2024

Nor'easter With Intense Snow Will Hinder Pre-Holiday Travel and Almost Promise a White Christmas in the Maritimes

December 20, 2024/ Alannah Campbell

It is going to start to look like Christmas across the Maritimes this weekend. The Nor’easter mentioned in yesterday’s preliminary forecast is making its way towards the Maritimes and will reach our shores this evening. While the low pressure center will pass south of Nova Scotia, the storm will bring 20-30cm of snow across some or all of the three Maritimes provinces.

Nova Scotia

Light snow will begin in Western Nova Scotia this evening, around 7-9pm, and spread eastward across the province throughout the remainder of the evening and overnight. The snowfall will quickly intensify, falling at close to 5cm/hr in some areas and continuing for several hours. This period of intense snow will result in widespread snowfall accumulations 20-30cm and possibly even higher locally before sunrise for most of mainland Nova Scotia.

In Guysborough County and into southern parts of Cape Breton Island, the snow will transition to ice pellets for a couple of hours, starting at around 3am as some of the warmer air from the storm pushes northward. This will limit snowfall totals in the area to 10-20cm.

Model run showing Snow (Blue), Rain (green), and Ice Pellets (Orange) at 4AM

The eastern half of the province will see a break in the precipitation before dawn, but the heavy snow will taper to light snow in the west which will continue through the morning. By noon, that snow will start to push eastward, possibly with a bit of light rain preceding it. The snow will start to taper off in Western Nova Scotia in the mid-afternoon and should end for most of the province by the evening. Some stray flurries will linger overnight and into Sunday morning, by they will provide very little additional accumulation.

New Brunswick

The entirety of New Brunswick can expect snow from this Nor’easter, but given its offshore track, the heaviest snow will be in the southeast and totals will decrease going northwest.

The snow will reach the Fundy Coast around midnight tonight and spread northward during the early morning hours. Southeastern New Brunswick can expect some heavy snow for a couple of hours that will quickly drive up accumulations. The snow will begin to taper off after sunrise, starting in the northwest and gradually through to the southeast by Saturday evening. This will bring snowfall totals in the southeast corner of the province above 20cm by the end of the day.

Prince Edward Island

The leading edge of the Nor’easter will cross into PEI shortly after midnight tonight. The snow will be continuous and last straight through to late Saturday evening. The snow will be heavy at times across the Island, falling at up to 2cm/hr and while not as heavy as expected in Nova Scotia, this will be enough to result in over 20cm of snow for the entire province.

Given that this is one of the busiest weekends of the year for travel, this storm will likely result in many headaches across the Maritimes. Heavy snow is already a pain to drive in, but widespread wind gusts up to 60km/h, and locally as high as 80km/h, will lead to blowing snow throughout the day Saturday. Not only will the roads be treacherous, but airports will likely have a handful of delays and cancellations due to the storm. Please give yourselves plenty of extra time if going out on Saturday and if possible, consider postponing any travel until Sunday.

For those who look at this storm as the chance for a White Christmas in over a decade in some places, there’s good news! Temperatures are not expected to climb above freezing until later next week so the snow will stick around.

December 19, 2024

Dreaming of a White Christmas? Incoming Storm Will Almost Guarantee One for the Maritimes!

December 19, 2024/ Alannah Campbell

It hasn’t really looked like the holiday season across the Maritimes lately, with grass still visible throughout the region. There’s been very little snowfall in Nova Scotia and PEI and the existing snowpack in New Brunswick melted just last week. A skiff of snow fell across New Brunswick overnight and this morning, but that’s the extent of the snow on the ground for pretty much the entire region. For those in the Christmas spirit though, that’s all about to change.

Starting Friday evening, a Nor’easter will move into the region that is expected to bring considerable heavy snow across most of Nova Scotia and into PEI and Southeastern New Brunswick. Weather models are currently projecting widespread snowfall accumulations of 20-30cm for that particular area and lower totals for the remainder of New Brunswick by Saturday evening.

The amount of snow expected in Guysborough County and much of Cape Breton Island is lower because some mixed precipitation is expected. Where, and how much of, this mixed precipitation falls will be entirely dependent on the track of the storm and there is still a bit of remaining uncertainty in that regard.

While some may be celebrating the likelihood of a White Christmas, the snow will certainly have negative impacts on early holiday travel this weekend. Not only will the heavy snow be a chore to drive in, widespread wind gusts up to 60km/h, and locally as high as 80km/h, will create even more hazardous conditions due to blowing snow. On top of that, there is the possibility of some isolated power outages with the strong winds.

This is only our preliminary look at the storm so check back tomorrow for a more in-depth forecast once the track of the storm becomes a bit clearer.

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 17, 2024

Winter Storm Could Dump Over 20cm of Snow on Parts of the Prairies Starting Wednesday

December 17, 2024/ Alannah Campbell

The latest winter storm set to impact the Prairies will bring heavy snow across a wide stretch of the region, from Grande Prairie into Southwestern Manitoba, over the next two days. The storm will also bring strong wind gusts, particularly in Southern Alberta, and the threat of mixed precipitation in Southwestern Saskatchewan.

Alberta

The storm will cross into Alberta through the Rockies early Wednesday morning. The snow will chart a continuous path as it pushes through the Rockies in the north, however to the south it will start to develop further east of the Mountains and while a few centimetres may fall, it will essentially skip over parts of Southern Alberta, including Calgary.

By around sunrise, the snow will spread across Central Alberta and into the Southeast corner of the province, where it will sit throughout the afternoon. The snow will be heavy at times, falling at up to 2cm per hour, which will lead to a widespread 10-20cm of snow falling by the end of the day from Grande Prairie, southeastward through Edmonton, and beyond the Saskatchewan border.

The snow will start to taper off from west to east in the late afternoon as the storm continues to track eastward and eventually ending in the evening, aside from some lingering scattered flurries.

There will be some strong wind gusts associated with this storm, up to 100km/h, but they are expected to be mostly isolated to the Southern Rockies and the Foothills, away from the heavy snow. Gusts of 40-60km/h are likely across the rest of Southern Alberta so blowing snow may be a concern, especially closer to the Saskatchewan border.

Saskatchewan

The leading edge of the snow will push its way into Southwestern Saskatchewan before sunrise Wednesday and it will spread eastward into the province through the morning and early afternoon. At that point, the band of snow will remain relatively stationary for several hours. It will also intensify over parts of Southern and Central Saskatchewan, leading to snowfall rates up 3cm per hour that will result in an area from Kindersley to Estevan seeing over 20cm of snow. Outside of this swath of the heaviest snow, much of the southern half of Saskatchewan can expect at least 5cm of fresh snow.

In the early afternoon, as the backside of the band of snow crosses into the province, some warm air will push in from the south. Temperatures on the ground will remain below freezing, but it will be warm enough aloft to result in freezing rain and/or ice pellets in Southwest Saskatchewan through the afternoon and into the evening.

The wind will also be a concern across Southern Saskatchewan and could result in reduced visibility due to blowing snow in the evening as gusts approach 80km/h. These conditions could very likely lead to highway closures across the region so keep that in mind when travelling in the area. The snow will start to make its way out of Saskatchewan in the evening and gradually diminishing across the province overnight and into the morning.

Manitoba

The storm will reach Manitoba by Wednesday evening, with snow starting in the Westman Region and extending deeper into the province through the rest of the evening and overnight.

Given the storm’s overall southeastward trajectory, the Southwestern portion of Manitoba can expect to be the most impacted. The snow will remain steady across this area overnight and into the morning, resulting in 5-20cm of snowfall. The greatest snowfall is expected in the southwest corner of the province and includes Boissevain, Killarney, and Virden. During the morning, the snow will start to spread further eastward towards the Ontario border, briefly bringing some light snow into the Winnipeg area before the storm completely exists the region by the lunch hour.

December 11, 2024

Return of Squalls to Ontario’s Snowbelt This Week With Blizzard Conditions & Over 50cm of Snow Possible

December 11, 2024/ Brennen Perry

While the brief break from lake-effect snow earlier this month brought milder air and rain to the snowbelt regions, the respite appears to be short-lived.

Snow squall activity is expected to make a comeback as we approach the end of the week. With multiple days of snow squalls anticipated, we could once again see impressive snowfall totals, rivaling those from earlier this month.

Colder air will begin to filter into Southern Ontario from the northwest late Wednesday afternoon, dropping temperatures below freezing through the evening. This influx of cold air will trigger the development of lake-effect snow bands, with ideal conditions persisting through Thursday and into Friday.

Current projections suggest two primary zones will bear the brunt of the snow squalls: one east of Lake Huron and the other southeast of Georgian Bay. The Lake Huron squall is expected to impact southern portions of Grey and Bruce counties, including Owen Sound, Chatsworth, and Meaford. Meanwhile, the Georgian Bay squall will likely target central Simcoe County, extending northward into southern Muskoka.

Snowfall totals in the hardest-hit areas could exceed 50 cm, with the possibility of approaching the staggering 100 cm seen in Bracebridge and Gravenhurst earlier this month. Whether such totals materialize depends on whether any of the snow squall bands remain stationary for extended periods.

To make matters worse, strong winds are expected to develop late Wednesday and persist into Thursday morning. Gusts could reach 60–80 km/h, particularly in Grey-Bruce and Simcoe County, significantly reducing visibility and creating hazardous travel conditions.

Blizzard conditions may develop, and travel is strongly discouraged during this timeframe. School bus cancellations are almost certain along the Lake Huron and Georgian Bay shorelines on Thursday.

The lake-effect snow is expected to begin late Wednesday afternoon, with the first band forming off Lake Huron. Initially driven by northwesterly winds, this band will target areas near Goderich before shifting northward as winds veer to a more westerly direction by evening.

By midnight, the main Lake Huron squall is expected to become stationary, affecting areas from Wiarton southward to Port Elgin, Owen Sound, and Meaford. Simultaneously, snow bands will begin forming off Georgian Bay, initially targeting Wasaga Beach, Midland, and Orillia. These may briefly lift northward Thursday morning, potentially reaching Gravenhurst and Bracebridge.

The most intense conditions are forecast for late Thursday morning into the afternoon. Two main corridors of concern are expected: Owen Sound to Collingwood off Lake Huron, and Wasaga Beach to Orillia off Georgian Bay. Snowfall rates will be exceptionally high, and the squalls could remain locked in place for 6–12 hours, leading to rapid accumulation.

Strong wind gusts during this period could result in blizzard conditions, with near-zero visibility on roads. Road and highway closures are likely in the hardest-hit areas, especially on Thursday.

By late Thursday night, the snow squalls may shift into the Bruce Peninsula and Muskoka regions. While the bands are expected to weaken by Friday morning, lingering activity could still produce scattered flurries before tapering off completely by the afternoon.

As with previous lake-effect events, it’s important to remember that these snow squalls are highly localized. Narrow bands of snow, often only a few kilometres wide, can result in dramatically different conditions over short distances. One location might see over 50 cm of snow while areas just a few kilometres away remain relatively unscathed.

We currently have high confidence in two zones being hardest hit: southern portions of the Bruce Peninsula, including Owen Sound, Chatsworth, Meaford, and Flesherton, and areas west of Orillia, including Midland and Coldwater. Accumulations in these regions could exceed 50 cm, with totals potentially nearing 100 cm if squalls remain stationary long enough. A more conservative estimate is 50–75 cm.

A wider swath of Grey-Bruce, including Kincardine, Port Elgin, Hanover, Lion’s Head, and Tobermory, as well as much of Simcoe County and northern portions of Kawartha Lakes, Gravenhurst, and Beaverton, could see 25–50 cm. Not all areas in this zone will hit these totals, as much depends on the placement and movement of the snow bands.

Further south and away from the snowbelt, accumulation decreases rapidly. Barrie itself may largely miss the snow, although it could see up to 25 cm if the bands shift slightly. The Georgian Bay squall may extend inland at times, bringing heavy snow to Lindsay and Peterborough, with 10–20 cm possible in these areas.

For regions in other parts of the snowbelt, including Muskoka, Parry Sound, Haliburton, and parts of Dufferin, Wellington, Perth, and Huron counties, totals are expected to range from 10–20 cm. The Golden Horseshoe, including London, Kitchener, and Guelph, will likely see only light flurries, with less than 5 cm expected.

December 07, 2024

The Second Storm of the Week Should Finally Bring Nova Scotia's First Decent Snowfall of the Season

December 07, 2024/ Alannah Campbell

For the second time in a week, more snow is on the way for the Maritimes, with another short-lived Alberta Clipper moving in to finish the weekend. Nova Scotians can once again expect rain with this system, but that won’t happen until after some snow accumulates, making this the first decent amount of snow across most of the province this season.

New Brunswick

The snow from the Clipper will arrive along the International border before sunrise Sunday morning and cross the province throughout the morning hours. The snow will be light to moderate, leading to a widespread 5-10cm across New Brunswick. Some light rain may mix with the snow along the Fundy Coast so snowfall totals could be limited here. Heavier snow is likely around Miramichi and into the Acadian Peninsula in the early afternoon, with snowfall rates reaching 2cm/hr and resulting in accumulations above 10cm in this area. By the early afternoon, the snow will start to taper off from west to east and ending in the evening.

Nova Scotia

The leading edge of the Clipper will push into Western Nova Scotia at around sunrise on Sunday. The western portions of the Annapolis Valley and South Shore will see this snow switch over to rain after only an hour or two, but as the system pushes further into the province through the morning, the snow will persist longer.

As we progress into the afternoon, the temperatures will rise to above freezing in mainland Nova Scotia, starting along the coasts and moving inland, causing the snow to transition to rain after only a few hours. As a result, snowfall totals will be higher, just above 5cm, in inland portions of the mainland and lesser along coastal areas. This snowfall won’t last and will quickly start to melt with the warmer temperatures and rain following it. The transition from rain to snow won’t occur until the evening in Cape Breton and the impacts of this will be limited overall. As usual, the higher elevations of the Highlands will remain cool, preventing a switch over to rain and resulting in snowfall accumulations above 10cm.

The system will start to make its way out of Nova Scotia starting in the late afternoon, with precipitation ending from west to east until finally exiting the province after midnight early Monday morning.

Prince Edward Island

The snow will reach Prince Edward Island around the lunch hour on Sunday and is expected to last throughout the afternoon before tapering off in the early evening. The snow is expected to be light, resulting in an almost province-wide 5-10cm of fresh accumulation with the exception of eastern King’s County, where temperatures will climb above 0° briefly in the evening and there will be a switch over to rain as the system finishes crossing the Island.

December 07, 2024

Fast Moving Clipper to Dump Up to 10-20cm of Snow on Parts of Ontario & Quebec This Weekend

December 07, 2024/ Brennen Perry

After a week dominated by seemingly endless snow squall activity across the snowbelt regions of Southern and Northern Ontario, the lake-effect snow machine is finally taking a break as we head into the first full weekend of December. However, this pause in squalls doesn’t mean the weather will be quiet for long!

We’re tracking a system originating from the Prairies that is expected to sweep across Ontario and Quebec between Saturday and Sunday. This fast-moving clipper will bring a widespread blast of snow, with accumulations ranging from 10 to 20 cm across Northern Ontario, Central and Eastern Ontario, and parts of Southern Quebec.

Precipitation associated with this system has already begun moving into Northwestern Ontario from Manitoba and will continue spreading eastward through the overnight hours. Areas near the international border, including Fort Frances, may also see a risk of freezing rain. Light to moderate snow will develop around Lake Superior and into Northeastern Ontario by Saturday morning.

As Saturday progresses, the system’s first snow bands will push southward into parts of Southwestern, Central, and Eastern Ontario by the afternoon. Initially, snowfall is expected to be light but could reach areas within the Golden Horseshoe. A sharp cut-off in precipitation means Deep Southwestern Ontario and regions along the Lake Erie shoreline are likely to see little to no accumulation.

By Saturday evening, the bulk of the precipitation will concentrate over Central and Eastern Ontario, where moderate to heavy snow will persist through the evening and into the early overnight hours.

Snowfall will taper off in Southwestern Ontario by the early evening and in the Greater Toronto Area by mid-evening. For the rest of Central and Eastern Ontario, snow will likely ease shortly after midnight, though areas closer to the Quebec border could see lingering snowfall into the pre-dawn hours.

During this time, temperatures in Southern Ontario will gradually rise, pushing many locations above the freezing mark and resulting in a mix of rain and snow. Central and Eastern Ontario, however, are expected to remain cold enough to keep precipitation as all snow.

For Quebec, snowfall is forecasted to begin mid to late Saturday afternoon, with Montreal likely seeing its first snow bands just after dinner. Snow will continue through the overnight hours and is not expected to clear out until late Sunday morning.

In terms of accumulation, this system is relatively straightforward compared to scenarios involving mixing or lake enhancement. Across Northern Ontario, a general 10 to 15 cm is expected, including areas such as Armstrong, Marathon, Wawa, Timmins, Chapleau, and Kirkland Lake. Isolated locations could see totals closer to 15 to 20 cm.

Farther south, snowfall totals of 10 to 20 cm are anticipated across much of Central and Eastern Ontario and Southwestern Ontario east of Lake Huron. This includes regions such as Grey-Bruce, Orillia, Muskoka, North Bay, Sudbury, Peterborough, Kingston, and the Ottawa Valley. Similar accumulations are expected in Southern Quebec, including Montreal, where snowfall amounts of 10 to 15 cm are likely, with localized pockets nearing 20 cm.

Meanwhile, lower amounts are expected in areas such as London, Kitchener-Waterloo, the Niagara Region, and the western GTA, where snowfall totals will likely remain around 5 cm or less. Toronto, in particular, may see minimal accumulation due to limited moisture reaching the area as the system concentrates on Central and Eastern Ontario. Deep Southwestern Ontario will likely see only trace amounts.

December 06, 2024

Messy Weekend Clipper Expected to Bring Widespread 10-20cm of Snow and Risk of Freezing Rain to the Prairies

December 06, 2024/ Alannah Campbell

It’s going to be a messy weekend across the Prairies with a Clipper expected to bring over 10cm of snow in a swath from Edmonton, through Saskatoon, to Winnipeg. This will be the first considerable snowfall of the season for the Winnipeg area, which has lagged behind the rest of the Prairie provinces by a couple of weeks.

The snow won’t be the only concern from this storm; there will be the risk of freezing rain across the region in pockets where temperatures will climb a degree or two above freezing. On top of the snow and freezing rain, some areas will also see rain from this storm, making for a mixed bag of a weekend!

Alberta

Our Clipper will start to make its way into Alberta in the Northern Rockies as a disorganized mess of rain, snow, and mixed precipitation mid-morning Saturday. Temperatures are expected to climb above freezing across much of Southern and Central Alberta so as the system pushes eastward into the province through the afternoon, the precipitation should fall as rain.

Things become much more organized in the evening and as temperatures start to fall, most of the rain in Central Alberta will switch over to snow. There will be the risk of brief freezing rain during this transition which could make surfaces quite icy before being covered with snow. With the organization of the storm, snowfall rates will increase and snow accumulations above 10cm should start around Edmonton and continue east-southeastward along the track of the storm.

As the system starts to exit the province early Sunday morning, some precipitation will actually push into Southern Alberta. There will be brief freezing rain along the leading edge, bringing trace ice accretion to Red Deer and eastward, followed by some moderate snowfall that will lead to 5-10cm of snow to the area, including Medicine Hat. The snow will taper off in the west through Sunday morning, but it is expected to linger in the east through the day.

Saskatchewan

The storm will extend into Saskatchewan starting in the late afternoon or early evening on Saturday. With the temperatures in the single digits, it will start off as a narrow band of rain. As the temperatures fall later in the evening, however, we expect there to be a transition over to freezing rain that will last for several hours as the storm continues its path southeastward. There could be a considerable track of ice accretion of 2-5mm that stretches from Saskatoon through Moosomin and into Southwest Manitoba.

Unfortunately, the freezing rain will eventually transition to snow from west to east overnight, which will cover the frozen ground, making things even more slippery. This snow will be moderate to heavy at times, with snowfall rates up to 2cm per hour, resulting in snowfall totals of 10-20cm over a wide stretch of the province.

During early morning hours of Sunday, snow will start to wrap around from the west, bringing 5-10cm of snow to Southwest and West Central Saskatchewan and lesser amounts along the International border. The snow will start to dissipate Sunday afternoon before ending Monday morning in the southeast corner of the province.

Manitoba

In a similar fashion to what is expected in Saskatchewan, as the Clipper crosses into Manitoba overnight Saturday, the leading edge will bring freezing rain into the province. This is only expected in the southwest corner of the province and the greatest ice accretion of 2-5mm will be found in an area that includes Virden and Boissevain.

After a few hours of freezing rain, the snow will follow and spread eastward across Manitoba through the morning. The storm will grow in size as the snow wraps around from the west in the early morning and the arrival of heavier snow in the afternoon will lead to a wider area receiving 10-20cm. The storm will start to push into Northern Ontario early Sunday afternoon and the snow will start to taper off overnight before eventually exiting the region by early Monday afternoon.

Widespread wind gusts of 50-70km/h are expected with the Clipper so on top of surfaces being quite icy over a wide area, blowing snow will be a concern As a result, we may see some highway closures throughout the duration of the storm. Road conditions will likely be very poor in the hardest hit areas so please take extra caution when travelling this weekend!

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