'Snow Day' Forecast: Heavy Snow Likely to Cancel School Buses in Parts of Southern Ontario on Tuesday

Brennen Perry

Published: February 15, 2025 - 7:54 PM

For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/4/8/bus-cancellations

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As we move into April, the chances of school bus cancellations continue to shrink with each passing day, especially as we begin to leave winter weather behind. However, winter isn’t done with us just yet. A late-season blast of snow could bring another round of disruptions to parts of Central and Eastern Ontario, with snowfall totals potentially reaching up to 25 cm over the next 24 hours.

The greatest potential for school bus cancellations lies in the northern sections of Central and Eastern Ontario, where snowfall warnings are currently in effect from Environment Canada. Areas most at risk include the Near North region—covering East Parry Sound and North Bay—as well as North Hastings under Tri-Board, and Renfrew County.

In these regions, the chance of a snow day is estimated at over 75%. However, while conditions are certainly favourable, the expected snowfall amounts sit right at the borderline for cancellations, so there isn’t enough confidence to push the probability up to 90%.

In the Ottawa region, even though a snowfall warning is also in place, the area is predominantly urban and has a higher tolerance for winter conditions when it comes to school transportation decisions. Historically, it takes a significant snowfall event to warrant widespread cancellations. Because of this, the probability has been set at a lower 25%.

That said, some weather models are showing the potential for more than 20 cm of snow in the area, and if those more aggressive forecasts come to pass, Ottawa’s snow day risk could increase sharply overnight.

Moving further south and west, the likelihood of school bus cancellations drops noticeably. Snowfall totals in these areas are expected to be much lower and likely won't reach the levels needed to trigger cancellations.

An exception to this could be communities along the Lake Huron shoreline. In these areas, heavier lake-effect snow bands may develop overnight, especially when combined with strong wind gusts, creating blowing snow and reduced visibility. Because of this, we've assigned a slight 25% chance of cancellations in those zones.

Meanwhile, no significant impacts are expected across the Greater Toronto Area (GTA) or Deep Southwestern Ontario. These regions are forecast to receive only a dusting of snow at most, with many areas likely to see little to no accumulation over the next 24 hours. As a result, we aren’t anticipating any school bus cancellations in these parts of the province.

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Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

The Never-Ending Winter Continues for Southern Ontario; Snowy System Could Dump Up to 25cm by Tuesday

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Residents across Southern Ontario, especially in the snowbelt regions, have certainly had their fair share of winter weather this season. From intense snow squalls back in December to the crippling ice storm that hit parts of Central Ontario just last month, it's no wonder that many are ready to say goodbye to winter.

Unfortunately, it seems that Mother Nature didn’t get the memo. Spring-like weather remains out of sight for at least the next week. Instead, the region is facing below-seasonal temperatures, with many areas struggling to reach the freezing mark during the day. On top of that, a fast-moving weather disturbance is currently affecting Northeastern Ontario with heavy snow. This system is expected to push into Southern Ontario late Monday as a cold front makes its way through the region.

Snowfall will intensify overnight and continue into Tuesday morning. The heaviest bands are expected across northern portions of Central Ontario and through the Ottawa Valley. Snowfall totals in these areas could easily exceed 15 cm, with some locations possibly seeing as much as 25 cm.

Elsewhere in Southern Ontario, lake enhancement and lake effect snow behind the system could lead to locally higher amounts—anywhere from 5 to 15 cm is possible around Lake Huron and along the southern shores of Georgian Bay.

Strong wind gusts of up to 80 km/h are also expected Monday evening into the early overnight hours around Georgian Bay, Lake Huron, and parts of Central Ontario. These gusts may create blowing snow and significantly reduce visibility at times.

More concerning, though, is the impact these winds could have on restoration efforts in areas still reeling from last month’s devastating ice storm. With nearly 50,000 Hydro One customers still without power after 10 days, additional outages are possible as the already fragile infrastructure struggles under the pressure of these gusty conditions.

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

As of Monday evening, heavy snow continues to fall across the Sudbury and North Bay regions, both of which have seen a significant dumping of snow throughout the day. By the time conditions begin to improve later this evening, localized snowfall totals will likely surpass 20 cm.

Further south, a sharp cold front is pushing a line of heavy snow across Southern Ontario over the next few hours. Along with the sudden drop in temperatures, this front could bring a quick burst of intense snowfall, leading to brief whiteout conditions and rapid accumulation.

Temperatures are still hovering just above freezing ahead of the front, which should help limit how much of the snow sticks at first, as the wet snow may melt upon contact with the relatively warm ground.

ESTIMATED WIND GUSTS- MAP FROM WEATHERBELL

Another concern this evening will be the development of strong wind gusts near Lake Simcoe and extending into parts of the Golden Horseshoe. Wind speeds could reach 60 to 80 km/h in localized areas.

While those wind speeds wouldn’t normally cause widespread issues, the combination of gusty winds and heavy snow could lead to pockets of blowing snow and reduced visibility, especially on the roads.

This area is also still recovering from the recent ice storm, with ongoing power restoration efforts in regions like Simcoe County, Peterborough, and the Kawartha Lakes. The added strain from tonight’s strong winds could cause further damage to the already weakened power grid in those communities.

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

After midnight, the focus of the heaviest snow will shift eastward into the Ottawa Valley. Persistent, moderate to heavy snow is expected across the region, especially in and around the City of Ottawa. One key area we’ll be closely monitoring is just west of Ottawa, where forecast models are showing the potential for a pocket of very heavy snowfall.

Communities including Algonquin Park, Barry’s Bay, Pembroke, and Petawawa could be directly impacted by this locally intense band of snow. If it shifts slightly east, it may sneak into Ottawa itself—something that could have a major effect on the Tuesday morning commute. Snowfall rates in this band may exceed 5 cm per hour, leading to near-whiteout conditions.

Additionally, more localized lake-effect snow bands could develop off Lake Huron and Georgian Bay early Tuesday. Based on current guidance, one of these bands may impact parts of Huron and Perth counties, with a small chance of reaching the London area, though whether or not London sees any snow will depend on exactly where the band sets up. Some weaker snow activity is also expected near the southern shores of Georgian Bay, including places like Owen Sound, Meaford, and Collingwood.

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

By Tuesday morning, snowfall will begin to taper off from west to east across the region. The Ottawa Valley will continue to see steady snow past sunrise, although it should begin to lighten up by early afternoon.

Lingering lake effect snow flurries may continue near Lake Huron and Georgian Bay, but are also expected to wind down by late morning as the system finally pulls away.

ESTIMATED WIND CHILL - MAP FROM WEATHERBELL

In addition to the snow, Tuesday will bring a blast of bitterly cold Arctic air to much of Southern Ontario. This late-season cold snap will make it feel especially harsh for those heading out in the morning. Once the wind chill is factored in, it could feel like the -20s across parts of Central Ontario.

Make sure to dress warmly, especially if you've already switched to a spring wardrobe. It might be time to dig out that heavy winter coat once again.

The frigid temperatures also pose an added risk for anyone still without power following the ice storm. Be sure to check in on friends, family, and neighbours who may be vulnerable to the cold, and if needed, make use of warming centres set up in the hardest-hit communities.

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The highest snowfall totals from this system are expected in the northern sections of Central and Eastern Ontario, including places like Sudbury, North Bay, northern Muskoka, Algonquin Park, Pembroke, Renfrew, and Ottawa. These areas are likely to receive 15 to 25 cm of snow in total, including the accumulation that began earlier on Monday.

Elsewhere in Central Ontario and extreme Eastern Ontario, along with areas east of Lake Huron, snowfall totals are expected to fall in the 5 to 15 cm range. The wide range is due to uncertainty about how much snow will stick, as the heaviest snowfall is forecast while temperatures hover near or just above freezing. Affected areas include Grand Bend, Goderich, Kincardine, Grey-Bruce, Collingwood, Simcoe County, Muskoka, Bancroft, Brockville, and Cornwall.

For much of Southern Ontario, less than 5 cm is expected, with the Golden Horseshoe likely seeing no more than a dusting. In Deep Southwestern Ontario, including Windsor, Chatham, and Sarnia, little to no accumulation is expected from this system.

'Ice Day' Forecast: Parts of Southern Ontario May See School Bus Cancellations on Thursday Due to Lingering Freezing Rain Impacts

For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/4/3/bus-cancellations

NOTE: SOME SCHOOLS ARE CLOSED DUE TO THE EARLIER ICE STORM. PLEASE CONSULT WITH YOUR LOCAL SCHOOL BOARD FOR A DETAILED LIST OF SCHOOL CLOSURES

A messy weather system is currently sweeping across Southern Ontario, bringing a mix of freezing rain, ice pellets, and heavy snow. As temperatures begin to rise later this evening and into Thursday morning, much of the precipitation is expected to transition to plain rain, gradually improving road conditions across the region.

Although freezing rain is not expected to persist into the Thursday morning commute, some roads—especially in rural parts of Central and Eastern Ontario—could still be icy. This lingering risk means there’s still a chance that school bus transportation could be impacted in a few regions, depending on how quickly conditions improve overnight.

It’s important to note that localized school closures remain in effect across some of the hardest-hit communities in Central Ontario. These closures are mainly due to ongoing power outages caused by the earlier ice storm. For the most accurate and up-to-date information, please check directly with your local school board, as the situation continues to evolve.

One area has already confirmed a cancellation for Thursday: Trillium Lakelands District School Board has announced that school transportation will be cancelled in both City of Kawartha Lakes zones. Ongoing recovery efforts and the continued lack of hydro have made transportation logistics extremely difficult. Communication towers remain down in the area, meaning bus drivers are unable to safely coordinate with bus companies, leading to the decision to cancel.

Looking further north, the highest probability of school bus cancellations lies in the Sudbury, North Bay, and Parry Sound regions. In these areas, freezing rain is expected to continue later into the night, only switching over to rain closer to the morning hours. As a result, road conditions are likely to remain icy by morning. The school boards covering these areas are known for being cautious, particularly when it comes to winter weather impacts on rural roads.

For Central and Eastern Ontario, the chances of school bus cancellations are more mixed, ranging between 25% and 50%, depending on the specific region and timing of the transition to rain. Boards that cover more rural or higher elevation areas will be more likely to see issues, while those in the southern sections of the region—where the switchover to rain will happen earlier in the evening—will have a longer window for melting and road improvement overnight.

At this point, the outcome could easily go either way. That’s why confidence remains low when it comes to predicting widespread cancellations despite the messy setup. While conditions are expected to improve quickly overnight, uncertainty lingers, especially for rural zones where icy backroads often remain a hazard well after the main part of the storm has passed.

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Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

Mid-Week Freezing Rain Risk Threatens Southern Ontario After Last Weekend’s Devastating Ice Storm

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With recovery efforts well underway across Central Ontario following the devastating ice storm last weekend—which left hundreds of thousands without power—a new weather threat is now on the horizon, potentially hindering progress.

A dynamic and complex system is expected to move into Southern Ontario starting Wednesday morning and continuing into Thursday, bringing with it a mix of impactful weather, including heavy snow, freezing rain, and even the risk of severe thunderstorms.

Unlike the recent ice storm, which brought over 30 hours of relentless freezing rain, this upcoming round will be more typical in nature. Most regions affected can expect four to eight hours of freezing rain, followed by a gradual transition to regular rain as temperatures rise.

While the severity won't match the last event, this system is still expected to bring 5 to 10mm of ice accretion in some of the hardest-hit zones, especially across higher elevations northwest of the Greater Toronto Area, including parts of the Dundalk Highlands and the Kitchener-Waterloo region.

That amount of ice is enough to snap tree branches and potentially cause power outages, especially with infrastructure already weakened. Thankfully, we don’t expect widespread or prolonged outages this time, and restoration efforts should be more manageable. However, with hydro crews still stretched thin from the last storm, even minor outages could take longer than usual to resolve.

Further north, across Central and Eastern Ontario, freezing rain is also expected—though it will be mixed at times with ice pellets and snow. These regions should see a faster changeover to rain, which will help limit overall ice build-up. Still, light icing and slick roads are possible through the afternoon and evening hours, particularly on untreated surfaces.

Adding to the concern are strong wind gusts, which are expected to develop Wednesday afternoon and could return overnight. Gusts may reach 70 to 90 km/h, especially in exposed areas of Central Ontario and regions east of Lake Huron. With already-compromised infrastructure, even moderate gusts could bring additional tree and power line damage.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

Precipitation will begin spreading into Southwestern Ontario late Wednesday morning into the early afternoon. For areas in Deep Southwestern Ontario and along the Lake Erie shoreline, including Windsor, Chatham, and Sarnia, the precipitation will fall as rain from the start, limiting any freezing rain risk.

However, higher elevation zones—particularly those east of Lake Huron and extending through Kitchener, Guelph, and Orangeville—will be dealing with below-freezing surface temperatures trapped under a layer of warm air aloft. This setup is classic for freezing rain, as the rain freezes on contact with cold ground surfaces.

The Greater Toronto Area could see some brief periods of freezing rain as well, particularly in areas away from the immediate lakeshore where it tends to stay cooler. However, any icing here is expected to be minor and short-lived, quickly melting as temperatures rise above freezing.

By mid-afternoon, Central Ontario, especially areas surrounding Lake Simcoe, will likely start off with a wintry mix of wet snow and ice pellets as the first bands of precipitation arrive. These areas could then transition to a few hours of freezing rain before warming into plain rain overnight.

ESTIMATED WIND GUSTS- MAP FROM WEATHERBELL

As the afternoon progresses, wind gusts will begin to increase, particularly in regions east of Lake Huron and into parts of Central Ontario. While model guidance varies, most are pointing to a window of potentially damaging gusts between 70 to 90 km/h.

The NAM model continues to show gusts near 100 km/h, though this may be on the higher end of the spectrum. Overnight, another round of strong gusts is possible as a line of thunderstorms develops. If these storms materialize, localized wind gusts could reach similar or even stronger levels. The severe weather threat should remain confined to Deep Southwestern Ontario.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

As we head into Wednesday evening, freezing rain will come to an end for much of the GTA as temperatures rise above the freezing mark. However, it is expected to persist longer across areas to the northwest, where colder air hangs on longer. This is where the most prolonged and severe icing is likely.

The freezing rain will also spread into parts of Central Ontario and the Bruce Peninsula, both of which were hit hard by the weekend storm and remain vulnerable to additional impacts.

Eastern Ontario will begin to see precipitation late in the day, starting with a burst of heavy snow, followed by a changeover to ice pellets and then freezing rain. How quickly this transition happens will determine how much snow is able to accumulate.

Some model scenarios suggest snowfall totals of 5 to 10 cm are possible, particularly in regions along the Quebec border including Ottawa.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

By around midnight, temperatures will begin to climb across regions southwest of Lake Simcoe, triggering a changeover to rain. Overnight, heavy rainfall will continue to spread across Southwestern Ontario and into the Golden Horseshoe. This rain may come down heavily at times, especially in areas that see embedded thunderstorms.

There is also a risk of severe thunderstorms through the evening and overnight hours in Deep Southwestern Ontario, including Windsor, Chatham, and Sarnia. These storms could produce wind gusts up to 100 km/h, and while the overall tornado risk is low, it can’t be ruled out. A more detailed thunderstorm forecast will be issued on Wednesday if conditions continue to trend toward severe potential.

The freezing rain will gradually lift northward into the Sudbury–North Bay–Ottawa corridor overnight. While these areas may deal with a few hours of freezing rain early on, a transition to rain is expected before daybreak on Thursday.

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The worst freezing rain impacts are expected across higher elevations of Southwestern Ontario and areas northwest of the GTA, where the freezing rain will last longest.

Some of these zones could see 5 to 10mm of ice accretion, and locally higher amounts over 10mm aren’t out of the question depending on exact temperatures and dynamics.

This kind of ice build-up can cause significant surface glazing and may lead to tree and power line damage. Areas most at risk include Listowel, Kitchener, Fergus, Guelph, Orangeville, Shelburne, and parts of York Region.

Northern parts of the GTA could see 2 to 5mm of ice, while areas closer to the lake should remain below 2mm, with ice melting quickly once temperatures rise.

Across Central Ontario and into the Ottawa region, a general 2 to 5mm of icing is expected, though this could trend higher if ice pellets are less dominant or the switch to rain is delayed.

RAINFALL ACCUMULATION - MAP FROM WEATHERBELL

Beyond the freezing rain, this system is also expected to deliver significant rainfall totals. Much of Southern Ontario could see 30 to 50mm of rain, with localized amounts up to 75mm possible in areas affected by thunderstorms.

With local waterways already running high due to spring runoff, this amount of rain could lead to flooding in low-lying areas, particularly where ice and debris continue to block drainage routes. This is of particular concern for communities still without power from the ice storm, as their ability to respond to flooding may be limited.

'Ice Day' Forecast: Another Freezing Rain Risk Threatens School Bus Cancellations in Southern Ontario on Wednesday

NOTE: SOME SCHOOLS ARE CLOSED DUE TO THE EARLIER ICE STORM - ONLY SCHOOL BOARDS THAT HAVE REGION-WIDE CLOSURES ARE HIGHLIGHTED ON THIS MAP. PLEASE CONSULT WITH YOUR LOCAL SCHOOL BOARD FOR A DETAILED LIST OF SCHOOL CLOSURES

While Central Ontario continues to recover from the devastating ice storm that struck over the weekend, yet another round of freezing rain is expected to impact Southern Ontario throughout the day on Wednesday. In the wake of the storm, widespread damage and ongoing power outages have forced several school boards to extend closures, with more potential disruptions likely as another system moves in.

The Trillium Lakelands District School Board (TLDSB) has confirmed that all schools will remain closed for a third consecutive day on Wednesday, April 2, 2025, due to extensive power outages still affecting the region. This closure comes as crews continue efforts to restore electricity and ensure school facilities are safe to reopen.

The Simcoe Muskoka Catholic District School Board has also announced multiple school closures for both Wednesday and Thursday. In the District of Muskoka, Monsignor Michael O’Leary, St. Dominic, and Saint Mary will remain closed. In Orillia, the following schools are affected: St. Bernards, Monsignor Lee, Notre Dame, Patrick Fogarty, and Foley.

Meanwhile, the Kawartha Pine Ridge District School Board (KPR) is planning to reopen schools on Wednesday, but some locations will remain closed due to localized outages. A complete list of affected schools is available on the board’s website: KPR School Closure Update.

Similarly, the Simcoe County District School Board (SCDSB) has announced that some schools will stay closed on Wednesday. Additionally, schools in Orillia will remain closed on Thursday as recovery continues. A full list of school closures can be found here: SCDSB Alert.

On top of these closures, there's growing concern over potential school bus cancellations across parts of Southern Ontario as Environment Canada has issued widespread freezing rain warnings in advance of this next wave. Rural school boards northwest of the Greater Toronto Area (GTA)—including Bluewater, Upper Grand, and Simcoe County—are facing the highest risk of bus disruptions. Freezing rain is expected to begin in the late morning and could significantly impact afternoon bus runs.

These regions currently face an estimated 75% chance of an “ice day” on Wednesday. However, the timing of the storm means school boards will need to make proactive decisions, as the worst conditions may arrive after morning transportation has already taken place.

In Eastern Ontario, freezing rain is also in the forecast, though it’s expected to begin later in the day. With the storm arriving after the afternoon commute, most buses will likely run as scheduled on Wednesday. That said, the risk of cancellations rises for Thursday morning as freezing rain is expected to continue overnight and could make for slick travel conditions at the start of the day.

For those in Deep Southwestern Ontario and the Golden Horseshoe, freezing rain is expected to be minimal. With temperatures hovering above freezing, most of this region will avoid major impacts, and school buses are expected to operate as usual.

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Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

Ice Storm Aftermath to Keep Many Schools Closed in Central Ontario for a Second Day on Tuesday

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As Central Ontario recovers from the weekend’s devastating ice storm, some school boards in the hardest-hit regions have decided to keep schools closed for a second day on Tuesday due to ongoing power outages and hazardous conditions.

As of 7 PM, the following English public and catholic school boards have announced closures:

• Trillium Lakelands District School Board – All schools closed.

• Kawartha Pine Ridge District School Board – Schools closed in Peterborough County, Peterborough City, Northumberland County, and Quinte West.

• Peterborough, Victoria, Northumberland and Clarington Catholic School Board – All schools in Peterborough, Peterborough County, and the City of Kawartha Lakes will remain closed. Schools in Northumberland will be open, except for St. Mary Catholic Elementary School in Campbellford, which is closed due to a power outage. Transportation to Northumberland schools will be cancelled. All schools in Clarington will be open, with transportation operating as usual.

• Durham District School Board - The following schools will be closed and no transportation will be provided: Beaver River PS, McCaskills Mills PS, Brock HS, Goodwood PS, Scott Central PS, SA Cawker PS

• Simcoe County District School Board - Schools in the central and north zones will remain closed to students. Clearview Meadows ES and Stayner Collegiate Institute will also remain closed.

• Simcoe Muskoka Catholic District School Board - Schools are closed in the North Zone (Elmvale, Midland, Penetanguishene & Orillia), Central Zone (Barrie, Innisfil & Angus), along with St. Dominic, Monsignor Michael O'Leary and Saint Mary's in Huntsville and St. Noel Chabanel in Wasaga Beach.

This article will be updated should any additional school closures be announced.

'Ice Day' Forecast: Schools Across Parts of Central Ontario Will Be Closed on Monday Due to Major Ice Storm Damage

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A major ice storm has left much of Central Ontario paralyzed, with widespread power outages and extensive damage. While the freezing rain threat has ended for the hardest-hit regions, the impact is far from over. Many communities remain without power, and recovery efforts are only just beginning. With power restoration expected to take days in some areas, school closures on Monday are inevitable.

As of 6:30 PM on Sunday, multiple school boards have already announced they will be closed on Monday due to the ongoing impacts of the storm. This includes Simcoe County District School Board, Trillium Lakelands District School Board, Kawartha Pine Ridge District School Board, and Simcoe Muskoka Catholic District School Board. These regions, among the hardest hit, are highlighted in dark purple on the map.

We are also highly confident that additional school closures will be announced in other severely impacted areas, including Tri-Board, North Durham, and Near North. Given the sheer number of power outages, downed trees, and icy roads, it’s difficult to imagine how schools in these regions could safely operate.

Dufferin and Meaford were also hit hard by the storm, and while some cancellations or closures are possible, the impacts there were not as widespread. As a result, the school board may opt to close select schools rather than issuing a full regional closure.

Meanwhile, in the Ottawa Valley, the impacts of this storm have been less severe. However, freezing rain is ongoing this evening and will continue into the overnight hours before transitioning to rain. Road conditions could still be hazardous, especially on rural routes. Because of this, there is a strong chance of school bus cancellations for the Renfrew and Upper Canada school boards.

As for the City of Ottawa, it’s a 50/50 call at this point. The urban school board generally has a higher tolerance for winter conditions since most students do not rely on rural bus routes. That said, with lingering ice and freezing rain, cancellations remain a possibility.

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Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

Dangerous Ice Storm Likely This Weekend With Widespread Power Outages Across Parts of Southern Ontario

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Concern is rapidly growing for what is shaping up to be a potentially devastating ice storm this weekend across parts of Central and Eastern Ontario. Prolonged freezing rain, beginning Friday evening, is expected to persist throughout much of the weekend, leading to substantial ice accretion on exposed surfaces.

This storm has the potential to reach ice accumulation levels not seen in years—or even over a decade. With up to 40mm of ice accretion possible, widespread power outages are likely in the hardest-hit regions, including Muskoka, Simcoe County, Kawartha Lakes, Peterborough, and Kingston.

Some of these power outages could last for days or even weeks, especially in more rural areas with dense tree coverage. Trees weighed down by ice are likely to fall, taking power lines with them. Travel conditions will also be significantly impacted, as ice-covered roads become extremely dangerous.

For Northern Ontario, the storm will start as a classic winter system, bringing heavy snowfall to Northeastern Ontario throughout Saturday. A second round of precipitation on Sunday could introduce freezing rain and ice pellets further south, affecting areas like Elliot Lake, Sudbury, and North Bay. Snowfall totals in Northeastern Ontario are expected to range from 20 to 30cm, making travel difficult.

Even the Ottawa Valley will see significant snowfall, with up to 20cm possible, along with a mix of ice pellets. By Sunday, freezing rain could become a concern for the region as temperatures rise and the precipitation type shifts.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

As of Friday afternoon, rain is already moving into Southwestern Ontario. By the evening, precipitation will spread north and east into Central and Eastern Ontario.

Based on the latest data, a band of heavy snow is expected to develop along a corridor stretching from Sudbury through North Bay and into the Ottawa region. To the south, an area of freezing rain will form over the Bruce Peninsula and extend into regions around Lake Simcoe.

ESTIMATED TEMPERATURE - MAP FROM WEATHERBELL

How far south the freezing rain spreads remains uncertain. Model guidance suggests surface temperatures will hover near the freezing mark across Barrie and the Greater Toronto Area (GTA).

Even a fraction of a degree difference could significantly alter how much freezing rain accumulates. If the air remains colder than expected, freezing rain could be more widespread. However, a slightly warmer scenario would push the freezing rain line further north.

Confidence is highest for freezing rain in northern sections of Simcoe County, Kawartha Lakes, and Muskoka. These areas are most likely to remain below freezing for an extended period, allowing heavy ice accretion to build up.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

The most intense icing is expected overnight into early Saturday morning. The worst conditions will stretch from Muskoka through Peterborough and into Kingston.

Once again, temperature will be the deciding factor. Some areas, such as Barrie and Newmarket, sit right on the edge between freezing rain and regular rain. If cold air lingers longer than anticipated, freezing rain could extend as far south as the northern GTA, as well as higher elevations like the Dundalk Highlands.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

Through Saturday morning and afternoon, light to moderate freezing rain or drizzle is expected to persist across portions of Central Ontario, particularly around Lake Simcoe. However, the intensity will decrease compared to the earlier hours.

Further south, rain will continue across Southwestern Ontario and the GTA. This is when we expect the warmest temperatures of the storm. Some areas in Deep Southwestern Ontario, including Windsor, could surge into the 20s, while Central Ontario remains near or below freezing.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

By Saturday evening, another round of heavy precipitation is expected to push into Central Ontario. At the same time, temperatures will steadily drop. Regions that saw rain in the afternoon—including parts of the GTA and Barrie—may transition back to freezing rain.

ESTIMATED TEMPERATURE - MAP FROM WEATHERBELL

Model data suggests that by late Saturday night into Sunday morning, the freezing rain line could shift southwest of the GTA. This could result in several hours of freezing rain across Kitchener, Waterloo, and parts of the Toronto area.

Deep Southwestern Ontario, including Windsor, Sarnia, and London, is expected to remain unaffected, staying well above freezing.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

Sunday morning will bring a gradual transition from freezing rain to regular rain across the GTA as temperatures climb above freezing. However, elevated areas northwest of the city, such as Guelph, Orangeville, and Shelburne, could see freezing rain linger for a few extra hours.

For Central Ontario, the freezing rain will continue into early Sunday afternoon as the main area of precipitation slowly shifts north.

By Sunday afternoon, the Ottawa Valley may begin transitioning from snow to ice pellets and then to freezing rain as temperatures rise.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

Most of Southern Ontario will warm above the freezing mark by late Sunday, finally pushing the freezing rain threat northward.

However, by Sunday night into Monday morning, the risk of freezing rain will shift to Northeastern Ontario, including Sudbury and North Bay.

Meanwhile, heavy snow and ice pellets will impact more northern regions, such as Wawa and Timmins.

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Predicting exact ice accretion remains challenging, as many factors influence how much ice actually builds up. The amount of freezing rain you experience may vary significantly from nearby areas due to microclimate effects, surface conditions, and temperature fluctuations.

Some high-resolution model runs suggest an extreme scenario with localized pockets of over 50mm—possibly even 75mm—of freezing rain. However, because much of this precipitation will fall in a relatively short timeframe, not all of it will necessarily adhere to surfaces.

Given this, we are forecasting general ice accretion between 25 and 40mm in the hardest-hit areas. This includes the northern tip of the Bruce Peninsula, Muskoka, Orillia, Barrie, Orangeville, Collingwood, Lindsay, Peterborough, Belleville, and Kingston.

If temperatures are slightly colder than expected, some locations could exceed 40mm of ice accretion, particularly where conditions allow for more efficient accumulation.

To put this into perspective, we can use the Sperry-Piltz Ice Accumulation Index (SPIA Index). With forecasted ice accumulations of 25-40mm (1-1.4”), this storm falls into a Category 4 ice event—even before factoring in wind.

While we are not expecting extreme winds, gusts of 40-50km/h (25-30 mph) in some areas could push this storm into Category 5 territory. According to the SPIA Index, a Category 5 ice storm results in:

Catastrophic damage to entire exposed utility systems, including both distribution and transmission networks. Outages could last several weeks in some areas. Shelters needed.

For the Greater Toronto Area (GTA), ice accretion amounts will vary significantly. The biggest factor will be how long cold air remains trapped at the surface.

We currently expect between 10-15mm of ice for northern parts of the GTA, including York, Durham, and Peel regions. Kitchener and Waterloo will likely see between 5-10mm.

Closer to the Lake Ontario shoreline—including downtown Toronto—freezing rain amounts should be lower, around 2-5mm. However, if temperatures are colder than expected, ice accretion in the GTA could be higher, so it’s still best to prepare.

To the north, ice accretion amounts will drop off as freezing rain transitions to ice pellets and snow closer to the Ottawa Valley.

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In terms of snowfall, widespread totals between 20-30cm are expected across much of Northeastern Ontario through Monday. This includes Sudbury, North Bay, Chapleau, Timmins, and Kirkland Lake. Even Thunder Bay could see 10-20cm of snow, mainly earlier in the weekend.

Along the Quebec border, snowfall amounts will range from 10-20cm in areas like the Ottawa Valley and Cornwall. Further southwest, freezing rain and ice pellets will be the dominant concern, leading to lower snowfall totals.

This storm remains highly dynamic, with small temperature fluctuations potentially making a massive difference in what type of precipitation falls. We will continue to monitor the latest data and provide updates as the situation evolves. Stay safe and stay prepared.

Potential Major Ice Storm Threat on the Horizon for Southern Ontario This Weekend

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With the end of March approaching and the arrival of April, winter’s grip on Southern Ontario is loosening. However, Old Man Winter isn’t leaving quietly. Instead, the final days of March bring the potential for multiple rounds of heavy freezing rain across parts of the region.

The risk of freezing rain is set to begin late Friday as the first wave of precipitation moves in. This initial bout of freezing rain could be quite heavy at times, particularly across Central and Southern portions of Eastern Ontario. The Greater Toronto Area (GTA) may also see some freezing rain late Friday before transitioning to regular rain as temperatures rise overnight.

A second wave of freezing rain is expected to develop Saturday evening and continue through Sunday. However, this round carries more uncertainty, with forecast models disagreeing on how far north warm air will push at the surface. Some models concentrate the freezing rain in Northeastern Ontario and the Ottawa Valley, while others bring it much farther south, placing the GTA in the bullseye.

While there is still uncertainty regarding the exact track and intensity of the freezing rain, all major weather models agree on the overall setup. Cold air will remain locked in at the surface across parts of Southern Ontario, while a surge of warm air moves in aloft. This combination will create ideal conditions for freezing rain formation.

These conditions are expected to persist throughout much of the weekend, with multiple waves of freezing rain possible. Given the prolonged duration of freezing rain, significant impacts are likely. Thick layers of ice could accumulate on untreated surfaces, including trees and power lines. The weight of this ice may lead to substantial damage to the power grid, with outages that could take days—or even weeks—to repair.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

Focusing on the first round, models are beginning to develop a clearer picture of where freezing rain will be most intense. Initial bands of precipitation should move into Southwestern Ontario by late Friday afternoon or evening.

As this precipitation reaches areas such as Kitchener, Owen Sound, and Barrie, it will encounter stubborn below-freezing temperatures at the surface. This will lead to freezing rain developing across these regions.

Further north, a band of heavy snow is expected to spread across areas near the northern shoreline of Lake Superior, extending into Timmins. In more southern locations, such as Sault Ste. Marie, Sudbury, and North Bay, ice pellets will likely be the dominant form of precipitation.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

Models agree that warm air associated with this system will gradually work its way toward the surface, beginning in the southwest and pushing northeast through the night. As a result, some freezing rain may mix with regular rain, especially southwest of Lake Simcoe and near the Lake Ontario shoreline in the GTA.

The persistence of cold air at the surface remains a major question mark. Some models suggest that cold air will be more stubborn, leading to more sustained freezing rain in the GTA overnight and into Saturday morning.

What is more certain is that a particularly intense band of freezing rain will set up over Central Ontario, including the Bruce Peninsula, Muskoka, Simcoe County, Peterborough, and Kingston. Significant ice accumulation is expected in these areas, with freezing rain continuing into Saturday morning. While freezing rain will persist into the afternoon, it should gradually become more scattered in nature.

In the Ottawa Valley, ice pellets and snow will be the main concern. There remains uncertainty regarding snowfall totals, as accumulation will depend on how much mixing occurs with ice pellets. Estimates currently range from 10 to 20 cm, but if ice pellets dominate, snowfall amounts could be closer to 5 cm.

TEMPERATURE - MAP FROM WEATHERBELL

Looking at the temperature setup for this event, a sharp gradient will be present across Southern Ontario on Saturday morning. This is one of the factors making this forecast so tricky.

Below-freezing temperatures will be well-established over Central and Eastern Ontario, as indicated by areas northeast of the pink line on the map above. Meanwhile, Deep Southwestern Ontario—including Windsor, Sarnia, and London—will experience double-digit temperatures, with no threat of wintry precipitation.

The most uncertain area lies between the orange and pink lines on the map above. This includes much of the GTA and the Grey-Bruce region. Temperatures in these areas will hover near the freezing mark, placing them at the boundary between warm and cold air. If models are off by just a degree or two, it could mean the difference between an ice storm and plain rain.

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This represents our preliminary assessment of the hardest-hit areas from the first round of freezing rain. It’s important to note that this forecast covers conditions through Saturday night, but the threat of freezing rain will persist into Sunday and even Monday. There is less certainty regarding how the second round will play out, so our focus remains on the first round for now.

Confidence is highest for significant ice storm impacts in locations such as Tobermory, Wiarton, Owen Sound, Collingwood, Orangeville, Barrie, Midland, Orillia, Muskoka, Parry Sound, Peterborough, and Kingston. Ice accretion in these areas will likely exceed 10 mm and could even reach 20 to 30 mm in the worst-case scenarios.

As previously discussed, temperatures will play a crucial role in determining the extent of freezing rain along the narrow corridor that includes the GTA and Kitchener. Slightly colder temperatures could mean prolonged freezing rain, while a warmer solution would allow for a quicker transition to rain overnight Friday.

Those in Deep Southwestern Ontario and along the Lake Erie shoreline should see little impact, as temperatures will remain well above freezing, resulting in plain rain rather than freezing precipitation.

For more northern regions along the Quebec border, ice pellets and snow will be the dominant precipitation types. Locations such as North Bay, Pembroke, and Ottawa could see 10+ cm of snow, with a risk of ice pellets and possibly brief periods of freezing rain.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

As the first round of freezing rain winds down across Southern Ontario, lingering pockets of freezing drizzle may persist across Central and Eastern Ontario through Saturday afternoon. In the GTA, temperatures could dip just enough to allow for a transition back to freezing rain later in the day.

The second round of freezing rain is expected to arrive by Saturday evening as energy moves in from the U.S. Midwest.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

Models are in solid agreement that this second wave will set up another band of freezing rain in the same areas hit hardest by the first round, including Central Ontario and portions of the GTA. This freezing rain will persist overnight into Sunday morning. However, by Sunday morning, the models begin to diverge significantly.

A more northern track would see warm air winning out across Southern Ontario, allowing temperatures to rise and leading to a transition to rain near Lake Simcoe. This would push the freezing line northward into Northeastern Ontario and the Ottawa Valley. In this scenario, freezing rain would be confined to areas such as Sudbury and North Bay, while heavy snow would develop from Wawa to Timmins.

Both the Canadian and European models favor this northern solution, which would be the better outcome for Southern Ontario, as it would avoid a second major icing event. However, this would be worse news for Sudbury and North Bay, where a significant ice storm could unfold.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

This more northern track has the warmer air winning out across Southern Ontario during the morning on Sunday. This gradually leads to a switch over to rain near Lake Simcoe as the freezing line puches north into Northeastern Ontario and the Ottawa Valley.

Then freezing rain would be contained to Northeastern Ontario including Sudbury and North Bay. While heavy snow extends from Wawa to Timmins.

Both the Canadian and European models favor this solution. Which would certainly be the better outcome for Southern Ontario as they escape a second icing event. But would be worst news for Sudbury and North Bay which could see an ice storm.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

On the other hand, the American model suggests a much more southerly track, which would place Southwestern Ontario and the Golden Horseshoe directly in the path of heavy icing. This scenario would bring freezing rain through Sunday night into Monday morning, creating hazardous conditions for the Monday morning commute.

If this outcome materializes, widespread school bus cancellations across Southern Ontario would be likely on Monday morning. Meanwhile, areas farther north could see accumulating snow on top of earlier ice buildup.

Unfortunately, a significant cooldown is expected in the wake of this storm. By Monday evening, temperatures will plunge into the negative teens. Any ice that accumulates over the weekend will remain in place for several days, increasing the strain on the power grid as trees continue to fall onto power lines.

Regardless of how this storm unfolds, it is shaping up to be a high-impact winter event with potentially severe consequences in some areas. Prepare for treacherous travel conditions and the possibility of widespread power outages lasting multiple days.

We will provide further updates as the weekend approaches. Stay tuned and stay safe!

'Snow Day' Forecast: Late Season School Bus Cancellations Possible on Monday Due to Heavy Snow

For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/3/24/bus-cancellations

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With the school year nearing the end of peak weather-related bus cancellation season, students in parts of Southern Ontario may still have a chance to squeeze in one more snow day before spring fully takes over.

A messy weather system is set to sweep across Southern Ontario overnight Sunday into Monday, bringing the potential for accumulating snow and hazardous travel conditions during the Monday morning commute. Areas around Georgian Bay could see up to 20 cm of snowfall, which may be enough to trigger widespread school bus cancellations in some regions.

Environment Canada has issued winter travel advisories for parts of Grey-Bruce, Parry Sound, and North Bay, making these locations the most likely to experience disruptions on Monday morning.

For students in the Near North District School Board, which covers Parry Sound and North Bay, the likelihood of a snow day is quite high, sitting at 75%. With these areas expected to receive the heaviest snowfall, and considering that this school board has a history of being cautious with winter weather, there's a strong possibility that school buses will be canceled on Monday.

The Bruce Peninsula, Northern Muskoka, and North Hastings (Tri-Board) face a more uncertain forecast, with the chances of a snow day sitting at 50/50. These areas are expected to see less snowfall overall. However, factors like blowing snow and reduced visibility during the morning hours could still result in cancellations, especially in rural and exposed areas.

For the rest of Grey-Bruce, along with South Muskoka and northern sections of Tri-Board, the chance of school bus cancellations is slight but not impossible. Snowfall amounts will likely be lower, but conditions could still lead to localized travel disruptions, particularly on untreated roads.

The probability of a snow day drops significantly for the rest of Southern Ontario, including Southwestern Ontario, the Golden Horseshoe, and Eastern Ontario. Snowfall in these areas is not expected to be heavy enough to warrant widespread bus cancellations. However, there remains a small chance (5-25%) of isolated cancellations, particularly in rural areas where road conditions can deteriorate more quickly.

While this storm won’t bring a province-wide snow day, those in the hardest-hit regions should keep an eye on overnight conditions and school board announcements early Monday morning.

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Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

Spring Snowstorm Could Dump Up to 20cm of Snow on Parts of Southern Ontario to Start the Week

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After an active month of wintry weather across Southern Ontario, March has taken a much calmer turn, bringing spring-like temperatures and even double-digit highs in some areas. However, don’t be fooled by the recent warmth—winter isn’t quite done with us yet. Despite what the calendar says, a surge of colder air will take over for the final days of March, setting the stage for a late-season snowstorm on the horizon.

An organized system is expected to bring heavy snow to parts of Southern Ontario starting late Sunday evening and continuing into Monday. Mixed precipitation will likely limit snowfall accumulation along the Lake Ontario and Lake Erie shorelines. However, further north, particularly around Georgian Bay, lake enhancement could boost totals, with some areas seeing 10-20 cm of snow. This storm could bring the most substantial snowfall in weeks, potentially impacting the Monday morning commute.

In addition to the snow, strong winds will develop on Monday morning and afternoon, with gusts reaching 50 to 70 km/h. This will lead to blowing snow and reduced visibility, especially in areas prone to drifting, such as Grey-Bruce.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

The messy weather is set to arrive Sunday evening, with the first bands of precipitation moving into Southwestern Ontario. However, the forecast remains tricky due to overnight warming temperatures. Some areas will start off with wet snow before transitioning to rain, especially near Lake Ontario and Lake Erie.

For Deep Southwestern Ontario, including Windsor, Chatham, Sarnia, and the Niagara region, snowfall will likely be limited as these areas will see mainly rain or a quick changeover from snow to rain after only a few hours. London, Goderich, and Kitchener will see more prolonged snowfall through the overnight hours, though freezing rain and ice pellets may mix in at times.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

The heaviest snow is expected to move into Central and Eastern Ontario by the pre-dawn hours of Monday, with several hours of steady snowfall along the leading edge of the system. However, since temperatures will be rising overnight, some of this snow may struggle to accumulate, particularly on road surfaces. Areas near the Lake Ontario shoreline may also see a mix of snow, rain, and ice pellets rather than steady snowfall.

By Monday morning, snow will continue spreading northeast, reaching the Ottawa Valley by sunrise. Given the timing, the snow could create challenging travel conditions during the morning commute, with reduced visibility and slushy roads. School bus cancellations may be possible in rural parts of Central and Eastern Ontario.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

While the widespread snowfall will taper off by late morning or early afternoon, lingering snow is expected around Lake Huron and Georgian Bay, where lake enhancement could lead to heavier localized snowfall. Grey-Bruce, Parry Sound, and North Bay will be among the hardest-hit areas, with additional accumulations into Monday night.

Meanwhile, for Eastern Ontario and the Golden Horseshoe, the bulk of the snow will be finished by midday Monday. However, light lake-effect snow will persist in the snowbelt regions throughout the rest of Monday into Tuesday. Some weak snow squalls could occasionally drift into Eastern Ontario and the Greater Toronto Area (GTA), but accumulation will be minimal outside of the snowbelt zones.

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By the time the system exits Monday evening, the highest snowfall totals will likely be in Bruce Peninsula, northeast Georgian Bay, and Northern Ontario, including Tobermory, Manitoulin Island, Sudbury, Parry Sound, North Bay, and Huntsville. These areas are expected to see 10-20 cm, with locally higher amounts possible.

That said, above-freezing temperatures for several hours on Monday could lead to melting and compacting of the snow, potentially reducing overall accumulations from what falls initially.

For Central Ontario, including Kitchener, Orangeville, Hanover, Owen Sound, Collingwood, Midland, Orillia, Bracebridge, and Bancroft, snowfall totals will generally range between 5-10 cm by Monday evening. However, some areas east of Lake Huron may see slightly higher totals, depending on lake enhancement.

For the Ottawa Valley, Southwestern Ontario, and the Golden Horseshoe away from the lakeshores, accumulations will likely stay under 5 cm. These areas may see a few centimetres of wet snow Sunday night, but overall, nothing significant is expected.

Regions directly along the Lake Ontario and Erie shorelines, as well as Deep Southwestern Ontario, will see little to no snowfall as rain or mixed precipitation will dominate.

Beyond Monday, lake-effect snow will persist into Tuesday, mainly affecting areas around Lake Huron and Georgian Bay, where localized snow squalls could bring a few extra centimetres.

The First Day of Spring Won’t Feel Spring-Like in Southern Ontario as Snow Returns on Thursday

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Although we’ve had an early taste of spring across Southern Ontario, the first official day of astronomical spring arrives Thursday morning. But don’t put that shovel away just yet! The mild temperatures we’ve been enjoying are about to be replaced by a surge of colder air over the next 24 hours.

Unfortunately, this means temperatures will drop back into the single digits, and in some cases, below freezing. Along with the cooler temperatures, scattered flurries are expected to develop in parts of Southern Ontario starting Thursday afternoon. While we aren’t anticipating significant accumulation, some areas could see a few slushy centimetres of snow on the roads. This could pose a challenge for those who have switched to summer tires a little too soon.

Looking ahead, it appears this below-seasonal trend will continue through the weekend and into early next week, bringing several chances for snow. Some of these systems could produce notable snowfall accumulation, especially for more northern sections of Central and Eastern Ontario over the weekend.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

Right now, a storm system is affecting Northeastern Ontario, with snow expected to continue overnight into Thursday morning. Areas including Sault Ste. Marie, Elliot Lake, and Timmins are on track to see heavy snow, with totals ranging from 20 to 40 cm in the hardest-hit locations.

For the most up-to-date details on the impacts on Northern Ontario, please refer to Environment Canada’s latest alerts by downloading our free weather app here.

Meanwhile, over Southern Ontario, a weakening line of thunderstorms is expected to push through during the pre-dawn hours of Thursday. When you wake up, it may still feel like spring, with temperatures near double digits in the morning. However, don’t be fooled—a sharp drop in temperatures is expected later in the day. If you’re heading out, it’s definitely a day to layer up!

Rainfall amounts will likely be fairly insignificant, with around 5 to 10 mm expected. However, localized areas could see higher amounts if they experience heavier thunderstorms.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

By Thursday afternoon, cold air will begin filtering into western sections of Southern Ontario, leading to a rain-to-snow transition starting as early as 1 to 3 PM for regions near Lake Huron and Georgian Bay.

With temperatures dropping close to the freezing mark and residual moisture from earlier rainfall, icy conditions could develop on untreated surfaces. While it doesn’t look like a true flash freeze, it could still result in hazardous travel conditions Thursday evening and into the overnight hours.

The snow is expected to persist into the evening, with the heaviest precipitation focused on Southwestern and Central Ontario. Areas in Eastern Ontario and around the Golden Horseshoe will likely avoid the transition to snow, as temperatures won’t drop enough before the precipitation exits.

temperature - MAP FROM WEATHERBELL

Friday, the first full day of spring, will start on a chilly note, with most of Southern Ontario waking up to temperatures at or slightly below freezing. This also means a risk of frost, so if you’ve started gardening early, you may want to bring in or cover any sensitive plants.

Factoring in the wind chill, some parts of Central and Eastern Ontario could experience feels-like temperatures in the -10s—a sharp contrast to the 20°C+ highs that many regions enjoyed on Wednesday!

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Despite this blast of colder air, we aren’t expecting significant snowfall accumulation on Thursday, especially compared to what Grey-Bruce and Muskoka have endured this winter.

However, there could still be some travel impacts, with 2 to 4 cm possible in areas including Kincardine, Hanover, Owen Sound, Wiarton, Tobermory, Parry Sound, Huntsville, Sundridge, and North Bay. Due to wet surfaces from earlier rain, some of this snow may melt on contact, leading to lower actual snowfall totals.

Elsewhere across Southwestern Ontario, Central Ontario, and the Ottawa Valley, a few flurries could fall Thursday afternoon into the evening, but accumulation will be minimal—at most 2 cm, and in many cases, it may not even stick to the ground.

This won’t be our last chance for snow in the coming days. We are closely monitoring a weak system that could bring a few centimeters of snow to Southern Ontario on Saturday.

Another system, arriving Sunday night into Monday, could be more significant. Early model data suggests it may bring over 10 cm of snow to parts of the region. However, the exact snowfall amounts will depend on the storm’s track, as it also appears to include freezing rain and mixed precipitation. We’ll be watching this closely and will have more details as we get closer.

Total Lunar Eclipse Alert: Rare Blood Moon Visible Across Ontario on Thursday Night

Image of a total lunar eclipse/blood moon

On the night of Thursday, March 13, 2025, into the early hours of Friday, March 14, Ontario residents will have the opportunity to witness a spectacular total lunar eclipse, often referred to as a “Blood Moon.” 

What to Expect

During a total lunar eclipse, the Earth comes directly between the Sun and the Moon, casting a shadow that gives the Moon a reddish hue. This phenomenon occurs as Earth’s atmosphere filters out shorter-wavelength blue light, allowing the longer-wavelength red and orange light to illuminate the Moon’s surface.

Key Times for Ontario

Eastern Daylight Time

• Start of Penumbral Eclipse: 11:57 PM on Thursday, March 13

• Start of Totality: 2:26 AM on Friday, March 14

• Maximum Eclipse: 2:58 AM

• End of Totality: 3:31 AM

• End of Penumbral Eclipse: 6:00 AM

The totality phase, when the Moon is entirely within Earth’s shadow and appears deepest red, will last approximately 1 hour and 5 minutes. 

Viewing Tips

• No Special Equipment Needed: Lunar eclipses are safe to observe with the naked eye. However, using binoculars or a telescope can enhance the experience by providing a closer view of the Moon’s surface.

• Optimal Viewing Locations: Find a dark area away from city lights to reduce light pollution. Elevated spots with an unobstructed view of the sky are ideal.

• Weather Considerations: Check local weather forecasts to ensure clear skies during the eclipse. Partly cloudy conditions may still allow for intermittent viewing.

TOTAL CLOUD COVER ON FRIDAY MORNING - MAP FROM WEATHERBELL

Viewing Conditions Across Ontario

• Southern Ontario: Forecasts indicate mostly clear skies throughout the eclipse period, providing optimal viewing conditions. However, some areas may experience pockets of partly cloudy skies, so it’s advisable to monitor local forecasts as the event approaches. Download our free app for your local forecast.

• Northern Ontario: Regions, especially Northwestern Ontario and areas around Lake Superior, may encounter heavy cloud cover, potentially obstructing the view of the eclipse. Residents in these areas should check local weather updates for the most accurate information.

Photography Tips

• Use a Tripod: To capture clear images, stabilize your camera to prevent blurring during long exposures.

• Adjust Exposure Settings: Since the Moon will be dimmer during totality, longer exposure times and higher ISO settings may be necessary.

• Practice Prior to the Eclipse: Familiarize yourself with your camera’s settings and practice shooting the Moon on clear nights leading up to the event.

'Snow Day' Forecast: Flash Freeze Risk Could Cancel School Buses in Parts of Southern Ontario on Thursday

For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/3/6/bus-cancellations

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After Southern Ontario got a brief taste of spring-like weather with mild temperatures and heavy rain on Wednesday, a drastic shift is about to take hold as temperatures plummet below freezing.

This sharp drop will likely lead to the development of icy roads, especially in areas where surfaces are still wet from rain and snowmelt over the past 24 hours. Blowing snow could also become a concern around Lake Huron and Georgian Bay, with lake-effect snow returning to those regions on Thursday.

While we don’t typically issue bus cancellation forecasts based on local road conditions, the situation is widespread enough to warrant a forecast, especially with Environment Canada alerts mentioning hazardous travel conditions.

The Trillium Lakelands District School Board (TLDSB) has already announced full school closures for Thursday, and it wouldn’t be surprising if other nearby school boards follow suit—at least in terms of school bus cancellations.

The school boards and bus consortiums most likely to cancel buses on Thursday include Bluewater, Near North, and Tri-Board, as they tend to be the most proactive when it comes to poor road conditions.

For the rest of the rural school boards across Central and Eastern Ontario, it’s a toss-up and will depend on local road conditions. Some areas in the orange zone could see cancellations, while others might run as usual. This uncertainty is exactly why we typically don’t issue forecasts for cancellations due to icy roads.

Urban school boards in the GTA and Ottawa are unlikely to be affected, as road conditions are generally much better in these areas.

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Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

'Snow Day' Forecast: Alberta Clipper May Give Some Students in Ontario a Long Weekend on Friday

For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/2/28/bus-cancellations

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A strong Alberta Clipper is set to sweep across Southern Ontario beginning late Friday morning, bringing widespread snowfall that will continue throughout the day. The heaviest impacts are expected in Central and Eastern Ontario, where snowfall totals of 10 to 20 cm are forecasted.

Environment Canada has issued snowfall warnings and weather advisories for many regions, signaling the potential for hazardous travel conditions. Based on these alerts, it is likely that some school boards will choose to cancel buses due to the expected dangerous afternoon commute.

However, confidence in widespread cancellations is slightly lower due to the timing of the snow, which will begin later in the morning rather than overnight. This means school boards will need to be proactive, making decisions early Friday morning based on the latest weather alerts and forecast updates.

The most proactive school boards, including Near North and Tri-Board (North Hastings), are the most likely to cancel buses, with a strong (75%) chance of cancellations on Friday. Other school boards across Central and Eastern Ontario have a lower but still notable chance, ranging from slight to 50/50, depending on the school board history and the level of Environment Canada alerts in effect.

Meanwhile, Southwestern Ontario and the Greater Toronto Area (GTA) are expected to receive less snow, with accumulations falling below the typical threshold for school bus cancellations. While roads may still be slick during the evening commute, widespread cancellations in these areas are unlikely.

Here is a breakdown of the likelihood of school bus cancellations by region:

Likely (75–90% Chance)

• Near North District School Board (All Regions)

• Tri-Board (North Hastings)

Possible (50–75% Chance)

• Bluewater District School Board (Bruce Peninsula)

• Simcoe County District School Board (North Zone)

• Trillium Lakelands District School Board (Muskoka, Haliburton & North CKL)

• Tri-Board (Central Hastings & North L&A)

• Renfrew County District School Board (Madawaska)

• Rainbow District School Board

• Algoma District School Board

Maybe (25–50% Chance)

• Bluewater District School Board (Rest of Regions)

• Simcoe County District School Board (West & Central Zone)

• Trillium Lakelands District School Board (South CKL)

• Kawartha Pine Ridge District School Board (Peterborough)

• Tri-Board (North & Central Frontenac)

• Renfrew County District School Board (Rest of Regions)

• Upper Canada District School Board

Unlikely (10–25% Chance)

• STWDSTS (Dufferin & Wellington)

• Simcoe County District School Board (South Zone)

• Durham District School Board (North)

• Kawartha Pine Ridge District School Board (Northumberland)

• Tri-Board (Rest of Regions)

• Ottawa-Carleton District School Board

For the rest of Southern Ontario, the chance of school bus cancellations is less than 10%.

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Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

Winter Returns to Ontario as End of Week Clipper Brings Widespread 10-20cm of Snow for the Start of March

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The first half of February has been nothing short of active across Ontario, with what felt like an endless stream of snowstorms dumping significant amounts of snow across many areas.

Fortunately, the latter half of the month provided a much-needed break from the active weather pattern. Milder temperatures pushed daytime highs above the freezing mark, leading to a steady melt of the extensive snowpack that had built up over previous weeks.

However, as the saying goes, all good things must come to an end. As we flip the calendar to March, active weather is set to make a comeback. A strong Alberta Clipper is on track to sweep across Northern and Southern Ontario on Friday, bringing widespread snowfall totals of 10 to 20 cm by Saturday.

In addition to the snow, this system will usher in much colder temperatures for the weekend. Wind chills are expected to drop into the -20s across Southern Ontario, while Northern Ontario will see even more bitter conditions, with wind chills dipping into the -30s. This will feel like a drastic change compared to the mild temperatures earlier this week, when parts of Southern Ontario saw highs in the mid to upper single digits.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

The first signs of the approaching clipper will be felt in Northwestern Ontario late Thursday night into early Friday morning, as snow spreads in from Central Manitoba.

Locations like Kenora, Dryden, and Thunder Bay will be the first to see snowfall, beginning around midnight and continuing into the early morning hours.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

As the system moves eastward, snow will taper off across Northwestern Ontario by late Friday morning, while the heaviest snowfall shifts to Northeastern Ontario, particularly around Lake Superior and Georgian Bay.

By this time, we’ll also begin to see light snow entering Southwestern Ontario, particularly around Lake Huron, which will become more widespread as the day progresses.

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

By Friday afternoon, snow will spread into Southern Ontario, becoming more steady across the Greater Toronto Area (GTA).

The heaviest accumulations will likely be concentrated along the Lake Huron and Georgian Bay shorelines, particularly in Grey-Bruce, Muskoka, and Parry Sound. Lake enhancement in these areas could provide an extra boost to snowfall totals.

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

The worst conditions for Southern Ontario will occur Friday evening, when snowfall rates could reach 2 to 4 cm per hour in the most intense bands. The snow will be widespread, impacting Central and Eastern Ontario, the GTA, and Grey-Bruce.

Additionally, blowing snow may become a significant issue, as wind gusts of 40 to 70 km/h could reduce visibility on the roads.

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

By midnight, snowfall intensity will begin to gradually diminish, and most areas southwest of Lake Simcoe—including the GTA—should see snow tapering off. However, lake-effect snow east of Lake Huron may continue into the overnight hours.

Meanwhile, light snow will persist overnight across Central and Eastern Ontario, but it is expected to slowly taper off by Saturday morning.

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In terms of Alberta Clippers, this one appears to be on the stronger side, with a fair amount of moisture to work with. While it will be fast-moving, we are still expecting widespread snowfall totals between 10 to 20 cm across much of Central and Eastern Ontario by Saturday morning.

Some areas could overachieve, with up to 25 cm possible, especially in regions east of Georgian Bay, where lake enhancement could further boost totals.

Further south, including areas like Goderich, Kitchener, Toronto, Peterborough, and Kingston, lower snowfall amounts are expected. While these regions will still see fresh snow, totals will likely range between 5 to 10 cm due to lower snowfall rates compared to areas further north.

For Deep Southwestern Ontario, including London and the Niagara region, snowfall will be minimal, with less than 5 cm expected.

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Across Northern Ontario, a wide swath of the region is on track to receive 10 to 20 cm from this system, including Dryden, Thunder Bay, Sault Ste. Marie, Timmins, Sudbury, and North Bay.

As with the south, there is potential for some areas to overperform, particularly east of Lake Superior, where localized totals of up to 25 cm are possible.

With accumulating snow, strong winds, and plummeting temperatures, this clipper will bring notable impacts heading into the weekend. Stay tuned for further updates as the system approaches!

'Snow Day' Forecast: Another Day of Likely Bus Cancellations in Southern Ontario’s Snowbelt on Wednesday

For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/2/19/bus-cancellations

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Snow squalls have continued to dump heavy snow across parts of the snowbelt region, particularly east of Lake Huron and along the southern shoreline of Georgian Bay, throughout the day on Tuesday. These intense bursts of snowfall have created near-whiteout conditions at times, making travel extremely difficult and forcing numerous road closures.

While squalls are expected to weaken overnight, road conditions will likely remain hazardous in the hardest-hit areas. Plows have struggled to keep up, with snow accumulating faster than it can be cleared. Many roads remain impassable, and even as crews work through the night, some routes may not be fully cleared by morning.

As a result, there’s a strong likelihood of another round of school bus cancellations on Wednesday, particularly in areas where rural backroads are still buried. The highest chances for a snow day include all of Grey-Bruce and northern Huron County, where widespread road closures have been reported.

Simcoe County may also see some bus cancellations, especially in communities closer to Georgian Bay, where snowfall has been heaviest and conditions remain the most difficult.

Outside of these core snowbelt regions, there’s a possibility of bus cancellations in Dufferin and Wellington counties, as well as northern Durham (around Beaverton) and parts of Kawartha Lakes. However, the likelihood in these areas is less certain and will depend on how quickly road crews can clear the snow overnight.

Here is a breakdown of the likelihood of school bus cancellations by region:

Almost Certain (90–99% Chance)

• Avon Maitland District School Board (Goderich)

• Bluewater District School Board (All Regions)

• Simcoe County District School Board (West Zone)

Likely (75–90% Chance)

• Avon Maitland District School Board (Listowel)

• STWDSTS (Dufferin)

• Simcoe County District School Board (Central Zone)

Possible (50–75% Chance)

• Avon Maitland District School Board (Exeter & Stratford)

• STWDSTS (Wellington)

• Simcoe County District School Board (South & North Zone)

Maybe (25–50% Chance)

• Durham District School Board (North)

• Trillium Lakelands District School Board (South CKL)

Unlikely (10–25% Chance)

• Thames Valley District School Board (Middlesex & Oxford)

• Waterloo Region District School Board

• Peel District School Board (North)

• Trillium Lakelands District School Board (North CKL)

For the rest of Southern Ontario, the chance of school bus cancellations is less than 10%.

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Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

'Snow Day' Forecast: Widespread School Bus Cancellations Likely in Southern Ontario's Snowbelt on Tuesday

For an updated list of school bus cancellations & school closures, please visit our live article: https://instantweatherinc.com/article/2025/2/18/bus-cancellations

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

Intense snow squalls have been pounding the snowbelt region, including Grey-Bruce and Simcoe County, throughout the day. Heavy snowfall and strong winds have created dangerous whiteout conditions, making travel nearly impossible in some areas.

As a result, plows have been pulled off the roads, and numerous road closures have been reported across Grey-Bruce due to the lack of visibility and the sheer volume of snow accumulating too quickly to clear.

With these intense squalls expected to continue overnight and into Tuesday, it’s hard to imagine school buses being able to operate safely in the hardest-hit areas. A snow day is looking like a near certainty for students across Grey-Bruce and parts of Simcoe County, including the City of Barrie, where snowfall rates remain extreme and drifts continue to build.

Beyond the snowbelt, blowing snow could still cause problems across parts of Southwestern and Central Ontario, extending into portions of the GTA. This may increase the likelihood of school bus cancellations in some areas, though the chances are lower the farther you get from the core snowbelt region.

Many school boards covering urban areas tend to have a higher threshold for cancellations, meaning decisions will likely depend on road conditions early Tuesday morning.

Here is a breakdown of the likelihood of school bus cancellations by region:

Almost Certain (90–99% Chance)

• Bluewater District School Board (All Regions)

• Simcoe County District School Board (West & Central Zone)

Likely (75–90% Chance)

• Avon Maitland District School Board (Goderich)

• Simcoe County District School Board (South & North Zone)

Possible (50–75% Chance)

• Avon Maitland District School Board (Listowel)

• STWDSTS (Dufferin)

Maybe (25–50% Chance)

• Avon Maitland District School Board (Exeter & Stratford)

• STWDSTS (Wellington)

• Durham District School Board (North)

• Trillium Lakelands District School Board (South CKL)

Unlikely (10–25% Chance)

• Waterloo Region District School Board

• STWDSTS (Guelph)

• Peel District School Board (North)

• York Region District School Board

• Kawartha Pine Ridge District School Board (Clarington)

• Trillium Lakelands District School Board (South Muskoka & North CKL)

For the rest of Southern Ontario, the chance of school bus cancellations is less than 10%.

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Disclaimer: Instant Weather has zero authority when it comes to bus and school closures.

It is completely up to the school boards, bus companies, local authorities, and parents to decide what is best for their children. This is our best guess based on our forecast.

Snow Squalls Target the Grey-Bruce and Barrie Area Again With Locally Up to 50-100cm of Snow by Tuesday

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Snow squalls are expected to become well-organized and intensify by Monday morning. One squall off Lake Huron will target southern Grey-Bruce, with periods of intense snowfall throughout the day. Thundersnow is even a possibility in this area.

Another squall will develop off the southeast shoreline of Georgian Bay, impacting parts of southern Simcoe County, including Wasaga Beach, Barrie, Angus, Innisfil, and Keswick.

These squalls will persist into the afternoon, shifting at times. The northern squall could push into Wiarton, extend across Georgian Bay, and come onshore near Barrie. Meanwhile, the southern squall off Lake Huron will stretch from Kincardine to Hanover and could push far inland, periodically bringing heavy snow into parts of the GTA.

By Monday night into Tuesday morning, the Lake Huron squall is expected to stall over southern Grey-Bruce, potentially leading to extreme snowfall accumulation. Wherever this band locks in, snowfall rates could reach an incredible 5-10 cm per hour. Some models suggest this squall could remain in place until Tuesday evening, somewhere between Owen Sound and Hanover.

The Georgian Bay squall may weaken somewhat after midnight but could persist into Tuesday. All snow squall activity should fizzle out by early Wednesday morning.

Projected Snowfall Totals:

• Localized amounts near 100 cm are possible in Grey-Bruce, with hotspots likely near Port Elgin, Hanover, Chatsworth, and Flesherton. Not everyone in this zone will see these totals, but some areas will get buried.

• 25 to 50 cm is likely across the rest of Grey and Bruce counties, extending into northern Huron and Perth counties. This also includes areas along the southeastern shoreline of Georgian Bay, such as Collingwood, Wasaga Beach, and Barrie.

• 5 to 15 cm could extend into Kitchener, Guelph, Durham, and York as occasional bursts of heavy snow push outside the core snowbelt region.

• The GTA may see light snow at times but is unlikely to receive more than 5 cm over the next two days.

Aside from the snow, we’re starting the week on a much colder note. If you’re heading outside for Family Day, be sure to bundle up—wind chills in the -20s are expected on Monday.

Stay safe and stay warm!

Strongest Snowstorm in Years to Bury Southern Ontario in Up to 50cm of Snow on Sunday

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Brace yourself, Southern Ontario! One of the biggest snowfalls in recent years is on the horizon for many parts of the region—excluding the usual snowbelt areas. This includes major cities like Toronto, Kingston, and Ottawa, which have largely dodged significant snowstorms over the past few years due to milder winters.

That streak ended earlier this week with the first storm in this parade of systems, dropping a widespread 20 cm or more across Southern Ontario. However, that system could pale in comparison to what’s coming next. This stronger storm is likely to bring 30 cm or more to a large portion of the region throughout Sunday.

As of Saturday afternoon, the first round of snow has already arrived, bringing steady snowfall from Southwestern Ontario into the Golden Horseshoe. This initial wave will be just the beginning, with up to 10 to 15 cm expected by the end of the day.

The second and much more intense round of precipitation will begin early Sunday morning as the system taps into tropical Gulf moisture and directs it straight into the Great Lakes region.

By morning and into the afternoon, conditions will deteriorate rapidly, with snowfall rates reaching 4 to 8 cm per hour. When combined with moderately strong wind gusts, this will lead to widespread blowing snow, significantly reduced visibility, and even localized blizzard conditions.

By the time the snow begins to taper off late Sunday, widespread totals of 30 to 50 cm are expected across Central and Eastern Ontario, extending into the Greater Toronto Area. The hardest-hit areas could even exceed 50 cm, particularly in Eastern Ontario, where elevation may enhance accumulation. Meanwhile, locations along the Lake Erie shoreline, including Windsor, Niagara, and Chatham, may see lower snowfall totals due to potential mixing with freezing rain or ice pellets.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

The first round of snow will continue steadily across Southern Ontario through Saturday evening and past midnight, with heavier snowfall targeting the Golden Horseshoe and the southern portions of Central and Eastern Ontario.

At the same time, the second round of snow will be rapidly developing south of the Great Lakes, forming over Indiana, Kentucky, and Ohio. This storm will strengthen quickly as it begins pulling in moisture from the Gulf of Mexico, which is also fueling severe thunderstorms across the southern U.S.

While there may be a brief lull overnight, don’t let it fool you—the worst is still ahead. The heaviest snowfall will begin to push into Southwestern Ontario before sunrise, bringing a rapid increase in snowfall rates from 1 to 2 cm per hour earlier in the night to 2 to 4 cm per hour by the early morning.

As the system intensifies, hourly rates of 4 to 6 cm—potentially even higher in the strongest bands—are expected. Road conditions will deteriorate quickly, with significantly reduced visibility and heavy blowing snow making travel extremely hazardous.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

Most areas will remain on the snowy side of this system, but there is some uncertainty regarding how far north a warm layer could push. This could lead to a brief period of ice pellets or freezing rain in areas along the Lake Erie shoreline, including Windsor, Leamington, Chatham, St. Thomas, Tillsonburg, Hamilton, and Niagara Falls.

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While significant freezing rain is not expected, some minor ice accretion of a few millimetres could occur, particularly right along the shoreline.

PRECIPITATION TYPE - MAP FROM WEATHERBELL

By early to mid-morning Sunday, the storm’s intensity will peak across Southwestern Ontario and the GTA, with snowfall rates reaching 4 to 6 cm per hour in many areas. In the strongest bands, these rates could climb even higher, creating whiteout conditions.

Wind gusts of 40 to 60 km/h will further reduce visibility, and there is even the possibility of thundersnow as some of these snow bands intensify.

Meanwhile, areas farther north, including regions around Lake Simcoe, Peterborough, and into the Ottawa Valley, will begin to see snowfall intensities climb to 1 to 2 cm per hour, eventually reaching 5 to 10 cm per hour by the early afternoon

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

The later part of Sunday morning after sunrise will see the worst conditions through Southwestern Ontario into the GTA as snowfall rates increase even further towards 4 to 6cm and possibility even higher in the strongest pockets of snow.

This snow will also be accompanied by increasing wind gusts near 40 to 60 km/h leading to blowing snow and blizzard conditions. Don’t be surprised to see some thundersnow during the morning as these bands of snow will be quite strong and could produce some lightning as they move through the region.

Snowfall intensity will also gradually increase through Central and Eastern Ontario with hourly snowfall rates reaching 1-2cm per hour around Lake Simcoe through Peterbough and into the Ottawa Valley.

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

As the system continues to push eastward, the most intense snowfall rates will shift into Central and Eastern Ontario. This is when travel will become nearly impossible in these areas as plows struggle to keep up with the rapid accumulation.

For Southwestern Ontario and the GTA, conditions will begin to improve slightly in the afternoon as the heaviest snow moves east. However, steady snowfall of 1 to 3 cm per hour will continue through much of the afternoon, with strong winds still blowing around earlier accumulations and keeping visibility low.

Snow will gradually taper off across Central and Eastern Ontario by Sunday evening, but blowing snow will remain a significant issue overnight. Travel will remain difficult even after the snowfall ends, particularly in areas with open terrain where drifting will be an issue.

By Monday, conditions should improve, but significantly colder air will move in. If possible, clearing snow on Sunday before temperatures drop is strongly recommended, as the snow will become much heavier to shovel once it settles and freezes.

ESTIMATED WIND GUSTS - MAP FROM WEATHERBELL

The strongest wind gusts will be found in Eastern Ontario, peaking during the early to mid-afternoon. Widespread gusts of 50 to 70 km/h are expected, with some areas, particularly around Ottawa and to the east, possibly seeing gusts near 80 km/h.

In comparison, the rest of Southern Ontario, including the Golden Horseshoe, will experience gusts of 40 to 60 km/h, while Southwestern Ontario will likely see gusts under 40 km/h.

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These wind speeds combined with the extreme snowfall rates expected across Eastern Ontario will almost certainly lead to blizzard conditions.

For a storm to meet the official criteria for a blizzard, winds of 40 km/h or greater must cause widespread reductions in visibility to 400 meters or less due to blowing and falling snow for at least four consecutive hours.

Based on current model data, it is highly likely that visibility will remain near zero for at least six hours from late morning to early/mid-afternoon in many parts of Eastern Ontario, surpassing the official blizzard threshold.

While it remains uncertain whether areas such as the GTA, Lake Simcoe, and Muskoka will officially reach blizzard criteria, blowing snow will still cause significant travel disruptions regardless of classification.

Regardless of whether your area officially meets blizzard criteria, this storm will create extremely dangerous travel conditions across much of Southern Ontario throughout Sunday.

Roads will become impassable at times, and even major highways will be difficult to navigate. Plows will struggle to keep up with the rapid accumulation, making travel nearly impossible in the worst-hit areas. If you don’t absolutely need to be on the roads, it is strongly advised to stay home.

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By the time the storm ends, the highest snowfall totals will be found across Central and Eastern Ontario, extending into portions of the GTA, with widespread accumulations ranging from 30 to 50 cm. Some areas, particularly in Eastern Ontario near Ottawa and through higher elevations to the west, could exceed 50 cm.

Regions around Lake Simcoe and the northern GTA will likely end up with 30 to 40 cm, though locally higher amounts are possible in areas such as the Dundalk Highlands. The Hamilton region and western GTA may see slightly lower totals, around 20 to 30 cm, due to the potential for ice pellets mixing in at times.

Southwestern Ontario, particularly along the Lake Huron shoreline, will see slightly less snowfall, with totals ranging from 20 to 30 cm. This includes areas such as Sarnia, London, Goderich, Grey-Bruce, Parry Sound, and North Bay. However, if the system strengthens earlier than expected, some of these locations could still exceed 30 cm.

Meanwhile, the lowest totals will be found along the Lake Erie shoreline, including Windsor, Chatham, and the Niagara region, where snowfall will range from 10 to 20 cm.

Looking ahead, colder temperatures are expected to settle into Southern Ontario by Monday. It would be wise to clear as much snow as possible on Sunday before the deep freeze sets in, as the snow will become significantly harder to move once temperatures drop.

Additionally, this colder air may trigger a resurgence of lake-effect snow early next week, which could lead to further significant snowfall accumulations in the typical snowbelt regions around Lake Huron and Georgian Bay. More details on that will come in a separate forecast.

This storm will be a major event, and conditions will be dangerous. If possible, stay home and avoid travel. We will continue to monitor the latest data and provide updates as needed. Stay safe!