A White Christmas is in the Forecast for Most of the Prairies, Odds are Not Good in Southern Alberta

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The second half of November and all through December have been marked by a series of snowstorms and periods of frigid temperatures across the Prairies. With Christmas only four days away, the odds of a White Christmas are becoming clearer.

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According to Environment Canada, in order for an area to have a White Christmas, there needs to be at least 2cm of snow on the ground as of 7am on Christmas Day. This is typically an easy threshold to cross in the Prairies and it appears that this year will be no different for most, but not all.

Currently, the snowpack is considerable across the Prairies, at least 10cm deep across a majority of the regions and large swatch where the snow is over 20cm in all three provinces. There are a few pockets where this is the exception, particularly in Southern Alberta where warm temperatures early in the week have resulting in little to no snow on the ground. Looking ahead over the next few days, some warmer air and a mix of rain and freezing rain will decrease the likelihood of a White Christmas for some.

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Modelled Snow depths as of Saturday, December 21st at 6am CT.

Manitoba

Northern Manitoba may see some scattered flurries this evening and overnight and again Tuesday morning. Otherwise, there is no other fresh snow expected between now and Wednesday morning. Temperatures will remain below freezing across the province until Christmas morning so no melting of the existing snow is expected. As a result, all of Manitoba can expect a White Christmas.

Saskatchewan

Like Manitoba, Northern Saskatchewan may see scattered flurries over the next few days, but no significant snowfall is expected. There is, however, a threat to White Christmas chances in Southwest Saskatchewan.

Early Sunday morning, temperatures in this area will climb to above freezing and will stay there throughout most of the day. Not only will this melt some of the limited snowpack in the area, a mix of rain and freezing rain will also result in melting. Temperatures are expected to rise once again on both Monday and Tuesday. With no additional snow in the forecast, a White Christmas can not be guaranteed in this area, but it is not completely ruled out.

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Alberta

The chances for a White Christmas will vary across Alberta. A large part of Southern Alberta already has less than 5cm of snow on the ground and daily highs in the single digits between now and Christmas significantly impact the chances of a White Christmas here. The relative warmth will also stretch northward, just east of the Rockies over the coming days, but the greater snowpack and temperatures only reaching a degree or two above freezing will keep the hopes for a White Christmas alive.

The only fresh snow in the forecast for the province will be isolated to the Mountains and far Northern Alberta. There’s the chance for some rain to cross through Southern Alberta overnight and through Sunday morning which will further hinder the likelihood of a White Christmas in the area.

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Please keep in mind that this is just a preliminary forecast and is based on current data. The forecast will be updated over the coming days, with the final forecast set to be posted on Christmas Eve. Make sure to stay tuned!

It’s a Christmas Miracle! A White Christmas Is Likely for Most of Ontario & Quebec This Year

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The month of December has truly delivered a winter wonderland for much of Ontario and Quebec, especially in the snowbelt regions of Ontario, which have seen significant snowfall from several rounds of snow squalls in recent weeks.

With Christmas just around the corner—less than five days away—the question on everyone’s mind is whether we’ll wake up to a White Christmas or a Green Christmas this year.

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For clarity, Environment Canada defines a "White Christmas" as having at least 2 cm of snow on the ground at 7 a.m. Christmas morning. Unfortunately, in recent years, Southern Ontario’s holiday season has often been marked by the Grinch’s meddling, with last year seeing widespread "Grinchmas" conditions.

Currently, the snowpack across much of the region is quite substantial, particularly east of Georgian Bay, into Northern Ontario, and across Quebec. The good news for these areas is that the forecast suggests little to no rain or mild temperatures between now and Christmas, making a White Christmas virtually guaranteed.

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However, the story is quite different for southern portions of the region, including Deep Southwestern Ontario and the Golden Horseshoe. These areas haven’t seen much in the way of significant snowfall accumulation this month, and the forecast includes a stretch of above-freezing temperatures on Christmas Eve and Christmas Day.

As a result, the odds of a White Christmas here depend entirely on whether snow can accumulate between now and Christmas morning.

Thankfully, hope isn’t entirely lost! A developing system is expected to move into Southern Ontario early Monday, continuing into Christmas Eve on Tuesday. Recent model updates have been promising for snow lovers, trending toward a stronger system that brings more widespread snowfall.

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Current projections suggest this system could deliver 10–20 cm of snow across Central and Eastern Ontario. However, for those along the Lake Ontario and Lake Erie shorelines, including parts of the GTA and Niagara Region, snowfall amounts may be significantly lower due to temperatures rising above freezing during the day on Monday. This could lead to melting or even a mix with rain, reducing accumulation to just a few centimeters.

With temperatures hovering slightly above freezing through Christmas Eve, it’s uncertain whether any snow from this system will survive until Christmas morning in these areas.

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WHITE CHRISTMAS REGIONAL BREAKDOWN

Central Ontario, including Muskoka, Tobermory, Bancroft, and Algonquin Park, has the best odds in Southern Ontario. These areas already boast a healthy snowpack from earlier systems and lake-effect snow, and Monday’s storm will only add to it. Temperatures are expected to remain below freezing, ensuring the snow sticks around. The chance of a White Christmas here is over 90%.

Eastern Ontario and areas near Lake Huron, including the Ottawa Valley and regions around Lake Simcoe, have a slightly lower chance at 75%. Eastern Ontario currently has little snow on the ground, but Monday’s system is expected to change that. Lake Huron’s shoreline, while already snow-covered, will face a brief warm-up Monday into Christmas Eve. While the snow is likely to hold, it isn’t guaranteed.

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For areas like Sarnia, London, Kitchener, Guelph, and Belleville, the chance of a White Christmas is more uncertain at 50%. Everything depends on how much snow Monday’s system delivers and whether it can survive the milder temperatures leading into Christmas morning.

In the GTA, including Hamilton and northern parts of Niagara, the odds of a White Christmas are slim with a 25% chance. Without an existing snowpack and with limited accumulation expected from Monday’s storm, above-freezing temperatures are likely to melt any snow that does fall. However, if the storm overperforms or the warm-up is less intense, we could see a last-minute boost in probabilities.

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Deep Southwestern Ontario, including Windsor and areas along the Lake Erie shoreline, is the least likely to see a White Christmas, with just a 10% chance. Monday’s system is forecast to bring minimal snow, and the prolonged warm-up will likely ensure a Green Christmas here.

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Northern Ontario offers little drama in this forecast. With widespread snow on the ground and no significant warm-up in sight, the region enjoys a 90%+ chance of a White Christmas across the board.

Much of Quebec also looks set for a picturesque holiday. The exception is the Montreal area, which currently has limited snow on the ground. However, like Eastern Ontario, this should change once Monday’s system moves through.

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This forecast remains preliminary and will be updated as we approach Christmas. Our final White Christmas forecast, set to be released on Christmas Eve, will factor in Monday’s storm and provide a clearer picture. If the snow cooperates, expect to see more 90%+ zones on the map. Stay tuned, and let’s hope for a festive, snow-covered holiday!

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

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

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

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

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HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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Nova Scotia

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

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

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

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

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New Brunswick

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

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

Prince Edward Island

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

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

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

'Snow Day' Forecast: Slight Chance of School Bus Cancellations in the GTA on Friday

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A system is forecast to arrive in Southwestern Ontario late Thursday, bringing light to moderate snowfall to the region overnight and into Friday morning. Along with this system, a lake-effect snow band is expected to form early Friday morning, affecting parts of the Greater Toronto Area (GTA) west of Lake Ontario.

While the overall snowfall accumulation will not be particularly significant—most areas will see 2-5 cm, with localized amounts of up to 15 cm in the lake-effect snow zone—the potential for reduced visibility is a concern. This will be especially true for the stretch between Toronto and Burlington during the Friday morning rush hour. As a result, there is a possibility of school bus cancellations, though it remains uncertain.

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The highest likelihood of cancellations is in the southern parts of Peel and Halton regions, where the most intense snow squall activity is expected. However, the probability is estimated at only 50%, as urban school boards in these areas typically require more substantial impacts to cancel buses. The decision will hinge on the strength of the snow band and whether it causes significant road issues when cancellation decisions are made in the early morning.

In surrounding areas, including Toronto and northern Halton, there is a slight chance (about 25%) of cancellations. While unlikely, the possibility cannot be entirely ruled out if conditions worsen unexpectedly.

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Elsewhere in Southwestern Ontario, the probability of cancellations is very low to low. The system's expected snowfall alone is insufficient to prompt widespread cancellations. However, some localized areas may experience reduced visibility during the morning commute, which could lead to isolated decisions by individual school boards to cancel buses as a precaution.

For Central and Eastern Ontario, no school bus cancellations are anticipated, as these regions are not expected to see significant snowfall from this system.

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As Friday marks the last school day before the holiday break, this will be our final snow day forecast for 2024. Thank you for relying on us for your snow day probability updates throughout the year. Our forecasts will resume the week of January 6th. Have a safe and happy holiday season!

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.

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

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

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

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

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

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

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

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

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

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

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

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

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HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

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

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

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

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

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

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

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

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

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

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Alberta

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

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

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

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

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Saskatchewan

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

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

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

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Manitoba

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

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

Freezing Rain Threatens Icy Sunday Across Saskatchewan & Manitoba

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What previously looked like a possible widespread ice event, according to weather models, has luckily down-scaled and will now only impact a narrow track across parts of Saskatchewan and Manitoba.

A disorganized system will cross into Southeast Saskatchewan from Montana after midnight tonight, travelling northeastward and reaching Manitoba shortly before sunrise. This system will only bring a narrow band of precipitation to the region, but due to the presence of warm air aloft and below freezing temperatures at the surface, this precipitation will fall as freezing rain. The freezing rain will be light and last for several hours, resulting in ice accretion amounts up to 5mm.

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Temperature Profiles and Precipitation Types

By around the lunch hour, the freezing rain will start to taper off and transition over to snow. As the entire system pushes eastward, Southern Manitoba will also start to see some snow moving in from North Dakota Sunday afternoon. The system will become more organized throughout the evening and overnight, leading to the development of additional snow in Central and parts of Northern Manitoba. There is still some uncertainty regarding exact snowfall amounts, but it looks like the southern half of the province can expect 5-15cm of fresh snow by the end of Monday.

'Snow Day' Forecast: Extra Long Weekend for Some Students in Ontario as Squall Likely to Cancel Buses on Friday

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Intense snow squall activity is forecasted to bring a significant amount of snow to parts of the snowbelt region east of Lake Huron and Georgian Bay overnight and into Friday morning.

These squalls are expected to persist through the morning hours, creating hazardous conditions with near-zero visibility on the roads. Given these dangerous travel conditions, it is highly likely that many school boards will opt to cancel buses for Friday. For some areas, this would mark the second snow day in a row, as buses were already canceled on Thursday.

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The highest confidence for school bus cancellations remains in areas like Grey-Bruce, Avon Maitland (Goderich), Simcoe (North), Trillium (Muskoka), and Near North (Parry Sound). With active snow squall warnings in place and the potential for over 50 cm of snow to accumulate overnight, there’s little doubt that buses will be unable to operate safely in these regions. We’re assigning a 90% probability of cancellations in these zones.

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Outside the core snowbelt areas, the situation becomes less certain. For locations such as Listowel, Simcoe (West), and Trillium (Haliburton), we estimate a 75% chance of cancellations. While they are fairly likely, it’s not a guarantee. Regions including the rest of the Avon Maitland District School Board (AMDSB), Wellington, Dufferin, Simcoe (Central), Trillium (Kawartha), and East Parry Sound have a 50% chance of seeing cancellations, as snowfall in these areas is expected to be less intense or more variable.

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For the rest of Southern Ontario, school bus cancellations on Friday are unlikely since the snow squall activity will remain localized to the snowbelt. This means a sharp drop-off in probabilities as you move farther away from the areas most heavily affected.

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.

Widespread Temperatures Below -30°C and Windchills Approaching -45°C Have Prompted More Extreme Cold Warnings

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The extreme cold continues across Saskatchewan and Manitoba overnight tonight and through to tomorrow morning. Unfortunately, it will be colder than this morning, and a much larger area can expect temperatures below -30°C to settle in after midnight and continue until the late morning.

This intense cold poses a risk to everyone, especially young children, the elderly, individuals with chronic illnesses, outdoor workers, and those without adequate shelter. Symptoms of cold exposure, such as shortness of breath, chest pain, muscle pain and weakness, numbness, and colour change in fingers and toes, should be monitored closely.

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The winds are expected be light again, at around 10-15km/h, as the temperatures reach their lowest point. With the even colder air than this morning, these light winds are going to result in windchills that are approaching -45°C. The coldest windchills are expected in the Westman Region, but windchills below -40°C will still be felt over a significant area. As a result, Environment Canada has issued more widespread Extreme Cold Warnings than last night, stretching from Saskatoon and into Northern Ontario.

At these temperatures, frostbite can occur in as little as 30 minutes, and in some areas close to 10 minutes, so it is crucial to cover up when going out and limiting exposure all together. It’s also wise to keep emergency supplies in your vehicle, including extra blankets and jumper cables, in case of an emergency.

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'Snow Day' Forecast: Blizzard Conditions on Thursday Likely to Cancel Many School Buses in Southern Ontario’s Snowbelt

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Snow squalls are forecast to develop late Wednesday and persist into Thursday, bringing substantial snowfall to areas around Lake Huron and Georgian Bay.

Strong wind gusts are expected to accompany the intense snowfall, prompting Environment Canada to issue a rare blizzard warning for parts of Grey, Bruce, and Huron counties. Meanwhile, other regions are under a strongly worded snow squall warning, with predictions of snowfall accumulation potentially reaching up to 80 cm in localized areas.

Given the expected hazardous conditions, it’s highly unlikely that school buses will be able to operate safely in the affected areas on Thursday. As a result, it is anticipated that many school boards will opt to cancel school buses and might even decide to close schools entirely, particularly in regions under a blizzard warning.

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The highest likelihood of a ‘snow day’ applies to the entire Bluewater District School Board (BWDSB), Avon Maitland District School Board (AMDSB) - North Huron, Simcoe County District School Board (North and West weather zones), Trillium Lakelands District School Board (Muskoka region), and Near North District School Board (NNDSB - Parry Sound area).

These areas, which are under snow squall or blizzard warnings, have a greater than 90% chance of bus cancellations.

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Surrounding regions, including the remainder of Avon Maitland District School Board (southern zones), Simcoe County District School Board (Central and South weather zones), Student Transportation Services of Wellington Dufferin (STWDSTS), and Trillium Lakelands District School Board (Kawartha Lakes and Haliburton regions), have a 50–75% chance of snow day cancellations.

Although these areas are still under warnings, they are not expected to experience the most severe conditions. While bus cancellations are still likely, the confidence level isn’t as high as in the core impact zones.

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The probability of cancellations drops significantly outside the snowbelt, as the squalls are expected to remain highly localized. Eastern Ontario may be the only exception outside the snowbelt which has a low chance (10–25%) of cancellations.

While icy road conditions from an overnight freeze following earlier rainfall are possible, it is unlikely to be severe enough to prompt widespread cancellations. However, the possibility cannot be entirely ruled out.

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.

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

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

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

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

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

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

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

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

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HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

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

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HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

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

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HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

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

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

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

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

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

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

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

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

Extreme Cold Makes Its First Appearance of December With Windchills Dipping Below -40°C

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The extreme cold has returned to the Prairies with temperatures dipping below -20°C across a majority of Saskatchewan and Manitoba, with the exception of the Southwest Corner of Saskatchewan. Temperatures will be lower than -30°C in parts of Central Saskatchewan and into the Parkland Region of Manitoba. The cold Arctic air pushed south throughout the day today and temperatures will continue to fall overnight before reaching their lowest point in the mid-morning.

This intense cold poses a risk to everyone, especially young children, the elderly, individuals with chronic illnesses, outdoor workers, and those without adequate shelter. Symptoms of cold exposure, such as shortness of breath, chest pain, muscle pain and weakness, numbness, and colour change in fingers and toes, should be monitored closely.

Winds overnight tonight are expected be light, at around 10-15km/h. These light winds will easily push the windchill below -40°C, which has prompted Environment Canada to issue Extreme Cold Warnings for parts of both provinces.

At these temperatures, frostbite can occur in as little as 30 minutes so it is crucial to cover up when going out and limiting exposure all together. It’s also wise to keep emergency supplies in your vehicle, including extra blankets and jumper cables, in case of an emergency.

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Rapidly Strengthening Bomb Cyclone Expected to Bring Heavy Rain and Wicked Winds to the Maritimes

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Hang on to your umbrellas! We have an incoming bomb cyclone that is set to not only drench the Maritimes, but bring some intense winds to the region as well. A bomb cyclone is a storm that undergoes rapid intensification, called bombogenesis, that results in a drop in central pressure of at least 24mb over a 24 hour period. A system has begun travelling northward along the American Atlantic Coast and the further north it travels, the stronger it is expected to become under this rapid intensification.

The storm will bring precipitation to the Maritimes in two rounds. It will start off with warm, moisture-laden air being funnelled up from the Gulf along the warm front, leading to temperatures climbing into the double digits. Following a break in the precipitation from the first round, the length of which will be dependent on the distance from the centre of the storm, a second round of rain will move in along the cold front. Behind this cold front, temperatures are expected plummet and will fall below 0°C across New Brunswick, leading to the risk of a flash freeze. Combined, these two rounds of rain will bring a widespread 10-50mm of rain across most of the Maritimes.

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New Brunswick

Things in New Brunswick will certainly get messy over the coming days due to this incoming storm. The first wave of precipitation will move into Western New Brunswick around sunrise Wednesday morning. The temperatures will rise with the arrival of the warm front and rain, but there will still be some isolated pockets of cold air near the surface that could persist for several hours, leading to freezing rain. Luckily any ice accretion will quickly melt as temperatures rise.

The rain will continue throughout most of the day and it will start to taper off, from south to north beginning in the evening. Due to its proximity to the centre of the storm, there won’t be a break between to the rounds of precipitation in Northwest New Brunswick. As a result, this is where the highest rainfall amounts of close to 50mm are expected. The rest of the province will start to see this second wave move in from the west overnight. It will lose intensity as it pushes eastward and the heaviest rain will fall over the western half of the province, where 25-50mm of rain is expected overall with the storm and only 10-25mm to the east. This second round won’t last long and will exit the province by the late morning.

There will be a unique problem in New Brunswick that the rest of the Maritimes won’t have to worry about. Some parts of the province have a considerable snowpack over 30cm which will end up melting with temperatures rising into the double digits through the day Wednesday. However, when combined with the amount of incoming precipitation and the ground likely remaining at least partially frozen, standing water and flooding becomes a concern. To make matters worse, the temperatures will drop drastically across most of the province overnight Thursday, to well below the freezing mark, which could lead to a widespread flash freeze.

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Nova Scotia

The scenario across Nova Scotia with this storm will be a little less complicated, in regards to precipitation. The first wave of rain will make its way into Western Nova Scotia in the mid to late morning Wednesday. The rain will be heavy at times across the western half of the Mainland and it will then dissipate across the province through the evening. The second round of rain will then arrive early Thursday morning and is only expected to last 4 hours or so as it crosses the province, before the storm finally makes its way out of the region in the evening. Most of Mainland Nova Scotia and along the South Coast of Cape Breton Island can expect 10-25mm of rain while the rest of the province will see 5-10mm

Prince Edward Island

Prince Edward Island, much like Nova Scotia, has a fairly straightforward forecast with this storm. The first wave of rain will impact the Island starting early Wednesday afternoon and continuing into the evening. Then, the second wave will move in after sunrise on Thursday and cross the Island in the span of 3-4 hours. Rainfall amounts of 10-25mm are likely in Prince and the western half of Queens County and 5-10mm in Kings County and the eastern half of Queens County.

Strong winds will also be a factor with the incoming bomb cyclone. In this model image showing 1:00 AM Thursday, we can get a good look at both the size and structure of the storm, along with the precipitation types and their intensities. What we also see is the projected internal pressure of the storm, in millibars, as well as the lines of equal pressure, in black, known as isobars. Winds are driven by air moving from areas of high pressure to those of low pressure and when isobars are really close in strong storms, as seen in this case, we know that the winds will be quite strong.

The strong winds will start making their way into the Maritimes Wednesday evening and they will peak overnight. The entire region will get hit by sustained winds above 40km/h and gusts over 70km/h, but Western Nova Scotia and Southwest New Brunswick in particular will be hammered by gusts in excess of 100km/h. These will be onshore winds so pounding surf and some coastal flooding are very likely along the Atlantic Coast of Nova Scotia and along the Fundy Coast to the west of St. John starting late Wednesday and continuing through Thursday morning.

'Ice Day' Forecast: Widespread School Bus Cancellations Likely on Tuesday in Central and Eastern Ontario

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Following Monday's freezing rain that brought icy conditions across Central and Eastern Ontario, the risk of freezing drizzle persists through the overnight hours.

Environment Canada has issued widespread freezing drizzle advisories, warning that the slick conditions could extend into early Tuesday morning. With temperatures remaining near or just below the freezing mark overnight, untreated surfaces are expected to stay icy well into the morning.

As a result, it’s likely that many school boards, particularly in rural areas, will opt to cancel school bus services on Tuesday morning due to the hazardous road conditions.

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The highest confidence for cancellations is in rural Eastern Ontario, where freezing drizzle is expected to still be occurring at the time decisions are made. These areas have been given a 90% chance of an “ice day.”

In the City of Ottawa, the likelihood is slightly lower at 75%, as the school board tends to be more conservative with cancellations in urban settings. However, the overnight icing should still be significant enough to prompt cancellations.

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In Central Ontario, the Parry Sound and North Bay region has the highest probability of cancellations at 90%. The school board in this area is typically more weather-sensitive, and the lingering freezing drizzle almost guarantees that buses will be cancelled.

The situation becomes more uncertain for Muskoka, Haliburton, and Kawartha Lakes. Here, the freezing drizzle is expected to taper off shortly after midnight, but icy road conditions are likely to persist into the morning, with temperatures remaining near freezing.

After Monday’s decision to proceed with buses in some areas backfired for Trillium Lakelands—forcing adjustments to afternoon routes—the school board is likely to exercise more caution on Tuesday to avoid similar issues.

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South and west of these regions, the chances of cancellations decrease significantly. Freezing drizzle is expected to end earlier in the evening, and temperatures are forecast to rise overnight, mitigating icy conditions. While cancellations cannot be entirely ruled out—particularly in Simcoe County—most other areas are unlikely to see disruptions to bus services on Tuesday.

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 Day' Forecast: Freezing Rain Threatens to Cancel School Buses on Monday in Parts of Southern Ontario

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Freezing rain is forecast to impact parts of Central and Eastern Ontario starting Monday morning and continuing throughout the day.

With Environment Canada issuing freezing rain warnings that highlight potential road hazards on Monday, it is highly likely that many school boards in the affected regions will choose to cancel bus services as a precaution.

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The highest likelihood of an “ice day” is focused on areas northwest of the GTA, particularly in higher elevations, as well as regions around Lake Simcoe and into Eastern Ontario north of the Lake Ontario shoreline.

For school boards in these areas, there is a 75% to 90% chance of bus cancellations. While confidence in cancellations is high, there remains a small possibility that some boards might take a gamble due to the later expected start of the freezing rain. This uncertainty has kept the chances from being universally set at 90%.

The only area where we feel a solid 90% confidence level is the southern portion of the Tri-Board district. Historically, this region has been very proactive in response to any Environment Canada winter weather warnings, so the presence of a freezing rain warning is likely enough to prompt cancellations there.

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Further north, including Muskoka, Haliburton, and the Ottawa Valley, messy weather may not arrive until later in the day. As of now, Environment Canada has not issued freezing rain warnings for these areas, which lowers the likelihood of bus cancellations.

Probabilities range from 25% to 50%, with just a 10% chance in the City of Ottawa. Urban cancellations in Ottawa typically require more severe conditions, so the lower chance is consistent with their past responses.

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In contrast, Southwestern Ontario and the GTA are expected to see mainly rain with minimal freezing rain, making school bus cancellations in these regions highly unlikely.

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.

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

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

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

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

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

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PRECIPITATION TYPE - MAP FROM WEATHERBELL

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

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

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

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

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

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PRECIPITATION TYPE - MAP FROM WEATHERBELL

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

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

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

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

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

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

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

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

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New Brunswick

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

Nova Scotia

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

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

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

Prince Edward Island

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

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

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

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

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

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

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

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

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

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

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

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

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