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

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

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

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

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

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

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

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

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PRECIPITATION TYPE - MAP FROM WEATHERBELL

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

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

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PRECIPITATION TYPE - MAP FROM WEATHERBELL

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

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

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

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

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

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

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

First Major Winter Storm of the Year Will Bring Up to 50cm of Snow and Blizzard Conditions to Saskatchewan & Manitoba

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The first major winter storm of the season for the Prairies is here, with rain already falling in Southeast Saskatchewan along with pockets of freezing rain and snow. In last night’s preliminary forecast, we discussed the complexity of this multi-day storm and now that the storm is on our doorstep, there is more confidence in the forecast. Some areas of Central and Northern Saskatchewan and into Northern Manitoba could now see upwards of 50cm by the end of Wednesday, with blizzard conditions possible in the south.

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As mentioned above, the first round of precipitation from this event has already made its way into Saskatchewan this afternoon. Rain is falling in Southeast and East Central Saskatchewan and there is snow further north, in the Hudson Bay area. The rain will transition over to snow as we progress through the evening with the heaviest snow expected to fall east of Prince Albert, from Melfort through to Cumberland House, starting later in the evening and continuing straight through to Wednesday morning.

As this band of precipitation pushes eastward into Manitoba overnight and into the early morning hours of Tuesday, it will encounter a strong low pressure system coming north out of the States. This incoming system from the south will bring steady rain, that is heavy at times, to Southern Manitoba throughout Tuesday morning. When the two systems meet, they will merge to form one large storm and by late Tuesday morning, cooler air will be pulled towards the centre of the storm from Northern Saskatchewan, leading to a transition of rain to snow with a brief period of freezing rain in the Westman Region.

By Tuesday afternoon, the snow will start to ease in Saskatchewan, but snowfall rates in Manitoba, on the other hand, will increase, leading to quick accumulations of snow. It’s at this point that the winds will start to pick up. Sustained winds of 40km/h and gusts exceeding 70km/h, combined with the heavy snowfall, will likely lead to blowing snow and blizzard conditions overnight Tuesday through to Wednesday morning.

This storm will finally diminish Wednesday afternoon, leading to a gradual tapering off of snow throughout the region.

‘Blizzard Conditions Possible’; Winter Storm Could Dump Up to 30cm of Snow on Parts of Saskatchewan and Manitoba Early This Week

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Mother Nature isn’t holding back as a powerful winter storm sets its sights on Saskatchewan and Manitoba, starting late Monday. This storm will bring heavy snow, strong winds, and even blizzard conditions, marking the region’s first significant taste of winter. Some areas in Eastern Saskatchewan and Western Manitoba could see up to 30 cm of snow, with localized amounts possibly exceeding that by the end of Wednesday.

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Sustained winds of 40 km/h, with gusts reaching 70–80 km/h, are expected to create blowing snow, particularly overnight Tuesday into Wednesday morning. Blizzard conditions could develop in some areas. Prepare for hazardous travel, as highway closures are likely in the hardest-hit regions.

Before diving into the details, it’s important to note that this is a complex storm, with snowfall accumulating over multiple days. This preliminary forecast provides a general idea of the storm’s potential impacts, but adjustments are likely as the system approaches. Stay tuned for updates, including a more detailed snowfall accumulation map in the coming days.

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PRECIPITATION TYPE - MAP FROM WEATHERBELL

The storm will begin in Saskatchewan late Monday afternoon or evening, as precipitation moves into the province from the south. The first round of snowfall will primarily impact Central and Northeastern Saskatchewan, with areas like Prince Albert and Nipawin expected to see the heaviest snow through late Monday.

Overnight Monday into early Tuesday, precipitation in Saskatchewan will merge with an approaching system from the south, targeting Manitoba. The exact track of this system remains uncertain, but it’s expected to bring significant precipitation to Manitoba throughout Tuesday.

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Initially, much of Eastern Manitoba, including Winnipeg, will see heavy rain. By Tuesday late morning or early afternoon, colder air will begin to wrap into the region, creating a risk of freezing rain in parts of Southwestern Manitoba, including Brandon and Portage la Prairie.

Meanwhile, heavy snow will persist across Eastern Saskatchewan, where Arctic air is firmly in place. There is some uncertainty about how far west the precipitation will extend into Saskatchewan, but the heaviest snow is expected closer to the Manitoba border.

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By Tuesday late afternoon, most of Manitoba will transition from rain to snow as colder air overtakes above-freezing temperatures. Heavy snow will continue through the overnight hours into Wednesday morning.

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SUSTAINED WIND SPEED - MAP FROM WEATHERBELL

Strong winds, with sustained speeds near 40 km/h and gusts of up to 70 km/h, will develop late Tuesday and persist into much of Wednesday. Combined with heavy snowfall, this will likely lead to blowing snow and blizzard-like conditions, particularly in parts of Eastern Saskatchewan and Western Manitoba.

As the system exits the region later on Wednesday, the snowfall will gradually taper off. However, this storm will usher in the coldest air of the season so far, with temperatures dropping to -10°C to -20°C by the end of the week.

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Snowfall Accumulation

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Monday

By the end of Monday, snowfall totals are expected to reach 5–10 cm in parts of Central and Eastern Saskatchewan, including Prince Albert, Melfort, and Tisdale. Surrounding areas, such as Saskatoon and Wynyard, could see up to 5 cm of snow.

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Tuesday and Wednesday

From Tuesday through Wednesday, snowfall totals are expected to range between 15 and 30 cm across much of the affected region. The heaviest accumulations are anticipated near the Saskatchewan–Manitoba border, where localized totals could exceed 30 cm. Elevation will play a significant role, especially in Western Manitoba, where areas of higher terrain could see as much as 30–40 cm.

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In Central and Eastern Manitoba, snowfall amounts are harder to pinpoint, as the transition from rain to snow will dictate final totals. Portage la Prairie could see 15–25 cm, while Winnipeg may only receive 10–15 cm, depending on how long the rain lingers before changing to snow.

A similar uncertainty exists in Saskatchewan, but for a different reason—how far west the moisture will penetrate into the province. Some forecasts keep the heaviest precipitation closer to the Manitoba border, while others push it further west. Regina sits on the edge of the higher accumulation zone, with current estimates suggesting 5–15 cm for the city and surrounding areas.

Up to 10cm of Snow Could Cause Traffic Headaches For Calgary Area to Start the Week

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The week will start off messy for those in Calgary and the surrounding area with up to 10cm of snow expected to fall on Monday. While not a large amount of snow, its morning arrival will likely make the commute longer than usual. Those in this area will definitely want to give themselves extra time to reach their destination in the morning.

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The snow will cross the Rockies into the province after midnight tonight, spreading eastward into Calgary by 2AM and then into Wheatland County shortly thereafter. This area can expect the snow to be heavy at times over the course of roughly 8-10 hours, leading to upwards of 10cm of accumulation by the afternoon. Light snow is expected to cross towards the Saskatchewan border by mid-morning, with the system losing organization in the afternoon. This will result in scattered flurries possible throughout Southern Alberta continuing into the overnight and early morning hours of Tuesday, leading to snowfall accumulations of less than 5cm.

Snowy Weekend Ahead for Parts of Southern Saskatchewan and Manitoba With Up to 20cm Possible

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It was only a matter of time before the first significant snowfall hit Southern Saskatchewan and Manitoba and a system moving northward from the States will deliver that.

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The precipitation will cross the border shortly after midnight tonight as it travels northeastward into Southeast Saskatchewan. This precipitation will be split between snow to the west and a pocket of rain to the east in the extreme Southeast corner of Saskatchewan as a result of a difference in temperature; below freezing in the west and positive single digits to the east. The temperature gradient will persist throughout the event and will result in areas of Western Manitoba seeing a brief period of light rain before temperatures drop and there is a transition to snow as the precipitation spreads.

The rain will be short-lived in Saskatchewan as the system pushes further into the region and cross into Manitoba by the mid-morning. At this point, the snowfall over Southeast Saskatchewan is expected to intensify, leading to widespread 5-10cm of accumulation in that area and into the Parkland region of Manitoba. A smaller area, that includes Carlyle, Estevan, Moosomin, Weyburn, and Dauphin can expect upwards of 20cm of snow as a result of this intensification through the afternoon.

By the mid-afternoon, the area of rain will start to expand eastward across the rest of Southern Manitoba, which will limit the amount of snowfall in Portage la Prairie and the Interlake Region. As the system continues to move across the region through the evening and overnight, a widespread 5-10mm of rain will fall across Southeast Manitoba.

The snow is expected to finish in Saskatchewan by midnight Saturday and the mix of precipitation will continue throughout Southern Manitoba until early Sunday afternoon. With the transition from rain to snow in some areas and a quick blast of up to 20cm of snow in others, road conditions will likely be poor so take extra care when travelling, particularly on Saturday.

A Brief Blast of Winter Will Blow Through Central Alberta to Finish the Week

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It was a snowy start to the week in Alberta and it looks like the same can be said for the end of the week as well. This time, however, the snowfall will be shorter-lived and not as widespread. Once again, temperatures hovering just above the freezing mark beyond the Rockies will result in precipitation falling as wet snow or a rain and snow mixture as the system tracks eastward across the province.

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Steady light rain is slated to begin in the Grande Cache area and the northern edge of the Rockies Friday morning. The rain will be mixed with snow in the mountains, leading to a bit of accumulation. By the evening, the rain will start to transition to wet snow which will begin to spread southeast into Jasper and along the Icefields Parkway. The snow will stall over this region for roughly 24 hours, leading to over 10cm of snow falling by Sunday morning.

On Saturday morning, a patch of precipitation will break away with a weak low-pressure center and push eastward across the width of the province over the course of the day. Given the single-digit highs expected across Central Alberta on Saturday and how quickly the system will move through the region, this light precipitation will likely fall as a mix of rain and snow and snowfall totals are forecasted to be less than 2cm.

After crossing into Saskatchewan, this patch of precipitation will lose a bit of its eastward momentum as the system interacts with an even stronger low coming up from the States that has been bringing historic snowfall to parts of New Mexico. As the system stalls, the snow will persist overnight Saturday and into mid-morning Sunday over an area just west of the Saskatchewan border, from Cold Lake to Lloydminster, bringing snowfall totals closer to 5cm.

It looks like snow is once again in the forecast to start next week so keep your shovels ready!

Update: Wintry Mix Continues, Pocket of Sub-Freezing Temperatures to Increase Snowfall Totals Tuesday

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It’s been a messy start to the week across parts of Alberta and into Southern Saskatchewan, with a low pressure system bringing mixed precipitation to the region today. This storm has been progressing as expected so far, but the latest data from weather models has resulted in some slight revisions to our forecast for Tuesday.

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Throughout the day Monday, we’ve seen temperatures above freezing across most of Southern and Central Alberta, resulting in precipitation falling as a rain-snow mix, and limiting overall snowfall accumulations. The exception to this has been in the Grande Cache area, where the temperatures have remained below 0°C and the precipitation has fallen as snow.

The single digit temperatures will continue overnight across most of Southern Alberta and Saskatchewan, but with being only being a degree or two above, or even at, freezing, we expect there to be a bit more snow accumulating beginning in the early morning hours Tuesday. This has been reflected by an increase in the forecasted snowfall for Taber, Brooks and north towards Strathmore and Drumheller.

As the temperatures begin to climb after sunrise, we will see the transition back to a rain-snow mix across the region. However, there is a small pocket where sub-zero temperatures will persist throughout the day, particularly in Medicine Hat, Maple Creek and the surrounding area. Steady snowfall will increase accumulations amounts to 5-10cm with locally higher amounts of up to 15cm possible in this area by the end of the day.

It is also expected that the precipitation from this system will push further eastward into Saskatchewan Tuesday afternoon and evening. By the late afternoon Tuesday, Arctic air will flood into the Prairies so the remaining light precipitation in Southern Saskatchewan at that point will fall as snow. As a result, we have extended the area covered by the 2-5cm range to include Outlook, Moose Jaw, and Assiniboia. Meanwhile, Saskatoon, Watrous, Fort Qu’Appelle, Estevan, and areas in between can now expect trace amounts (less than 2cm) of snow. The snow will diminish overnight, but scattered light flurries are possible in Southeast Saskatchewan Wednesday morning.

Messy Wintry Mix to Impact Alberta & Saskatchewan for the First Week of November

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The first week of November is going to have an active and messy start across Southern Alberta and Saskatchewan. The arrival of a low pressure system will bring widespread precipitation Monday and Tuesday, but the dominant type of precipitation that falls will vary throughout the region.

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The low pressure centre will cross into Alberta Monday morning in the Grande Cache area, bringing steady light snow to the area. As the low gradually travels southeastward across the province throughout the day and overnight, the precipitation will follow and spread across much of Central and Southern Alberta and continue for most of the day Tuesday. The low will move into Saskatchewan by early Tuesday morning, bringing precipitation to the southwest region of the province throughout the morning and into the late evening before dissipating.

The exact snowfall accumulation across Alberta and Saskatchewan from this system has been tough to forecast, with temperatures in the single digits for a large part of the region, meaning that the precipitation will fall as a mixture of rain and snow. This, combined with still mild ground temperature, should greatly reduce overall snow accumulations. As a result, we’ve gone with a more conservative snowfall forecast. The areas with the greatest snowfall potential, and the least mixing, will be found to the west of the low pressure system, behind its associated cold front and in the area with the coolest air, namely in the Grande Cache area and through the Rockies.

Spooky Skies Ahead! Southern Ontario Could See Warmest Halloween on Record; Up to 10-15cm of Snow Could Haunt Northern Ontario

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Excitement is brewing as Halloween night approaches, and the streets are set to fill with little ghosts, goblins, and creatures of the night. However, it seems Mother Nature may have skipped the “or” in Trick-or-Treat this year. While Southern Ontario is in for an unusually warm treat, there’s also a wintry “trick” in the forecast, as the first messy winter system of the season stirs up across the northern portion of the province.

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Before we dive into the chilly details, let’s savor the treat: a Halloween night warmer than most! Unlike Halloweens past, where bone-chilling temperatures hovered near or below freezing, this year brings weather that feels more like late summer or early fall. Temperatures across Southern Ontario will keep that warm spell lingering, with some areas possibly experiencing record-breaking highs for Halloween.

In years past, Canadian trick-or-treaters have bundled up with extra layers under their costumes to ward off the cold. This Halloween, they may find themselves shedding layers, with temperatures expected to reach the upper teens and even low 20s in some spots.

Prime trick-or-treating time around 8 PM will bring readings of 16-20°C across much of Southern Ontario, with slightly cooler temperatures between 14-16°C around Algonquin Park and the Bruce Peninsula. Daytime highs earlier in the day may reach the low or even mid-20s, with some areas potentially setting new temperature records.

However, Halloween night won’t stay warm for long. A cold front will sweep through late in the evening, quickly dropping temperatures as it ushers in much colder air overnight. Those celebrating late into the witching hour should brace themselves for temperatures plunging into the single digits by early Friday morning.

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Northern Ontario’s Ghostly Chill

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While Southern Ontario basks in warmer weather, the tale turns a bit chillier in Northern Ontario. Southern portions of Northeastern Ontario, including Elliot Lake, Sudbury, and North Bay, will enjoy temperatures between 12-16°C during Halloween evening. But for Central Northeastern communities like Chapleau, Temiskaming Shores, and Kirkland Lake, temperatures will drop to single digits, adding an extra shiver to the festivities.

Northwestern and Far Northern Ontario will already be feeling the effects of the cold front by trick-or-treat time, with temperatures hovering near or just below the freezing mark. In these areas, those venturing out for Halloween night will definitely need to incorporate extra layers into their costumes.

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So, Where’s the Trick?

PRECIPITATION TYPE FOR Halloween EVENING - MAP FROM WEATHERBELL

You may be wondering, with all this warm weather, where’s the trick in this Halloween forecast? The trick this year will be what’s coming down from the sky. Scattered rain showers are set to creep into Southern Ontario starting Thursday afternoon, with the heaviest rainfall likely in parts of Northeastern Ontario and along the western areas of Southern Ontario.

In fact, there could even be isolated thunderstorms around Georgian Bay. So if you’re out collecting candy, keep an eye on the skies, and take cover if you see lightning or hear thunder. Trick-or-treaters in Eastern Ontario, on the other hand, might just escape the rain until later in the evening.

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Fortunately, rainfall amounts across Southern Ontario are expected to stay light, with 5-15 mm in areas seeing the heaviest showers. Thunderstorm activity could increase these totals in very localized spots, but nothing overly dramatic.

The heaviest rain will be concentrated in Northeastern Ontario, stretching from Sault Ste. Marie through Sudbury and up to North Bay. Some of these areas are currently under a rainfall warning from Environment Canada, with up to 60 mm of rain possible from Wednesday night through Friday morning.

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A Halloween Surprise: Snow in Northern Ontario!

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And now, for the big Halloween scare! As rain moves across Ontario, colder air in the north will bring a chilling twist, transforming rain into snow by Thursday afternoon in some areas. The spooky snowfall is set to begin from Wawa up through Kapuskasing, with heavy snow expected to continue through the overnight hours into Friday morning.

For those areas in the “snow zone,” accumulation could be significant. A corridor stretching from Wawa to Kapuskasing may see up to 10-15 cm of snow by Friday morning, though actual amounts may vary based on temperatures near the freezing mark, which can affect how well snow sticks to the ground.

Surrounding areas, including Wawa, Kapuskasing, Timmins, and Cochrane, could see 5-10 cm of snow accumulation. However, warmer ground temperatures may mean that some snow melts on contact, reducing the totals.

Northeastern Ontario, north of a line from Sault Ste. Marie to Sudbury, may also pick up a dusting to a few centimetres of snow Thursday night into Friday, with up to 5 cm possible. Thunder Bay could even see a few flurries, though no accumulation is expected there.

So, Ontario, prepare for a Halloween that’s part treat, with warm weather for many, and part trick, with rain and snow making an appearance in others. However, you plan to celebrate, have a safe and spooky Halloween night!

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

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

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

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

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A Weak Weather System and a Chance of Snow

PRECIPITATION TYPE FOR SUNDAY EVENING - MAP FROM WEATHERBELL

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

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

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

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Potential for Accumulation and a Hard Freeze

ESTIMATED MINIMUM TEMPERATURE ON MONDAY MORNING - MAP FROM WEATHERBELL

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

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

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

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Midweek Warm-Up on the Horizon

ESTIMATED DAYTIME HIGH TEMPERATURE ON WEDNESDAY - MAP FROM WEATHERBELL

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

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

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

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What’s in Store for Halloween?

ESTIMATED TEMPERATURE FOR HALLOWEEN AT 8 PM - MAP FROM WEATHERBELL

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

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

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

First Significant Snowfall of the Season Expected Across Alberta to Start the Week

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On the heels of some mild temperatures for the past week, a drastic cool down is already on its way courtesy of a strong cold front. Precipitation is expected along this cold front and unfortunately, the temperatures will dip low enough across much of Central and Southern Alberta for some of that precipitation to fall as snow, hitting the region in two rounds.

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The cold front has already started to make its way through Alberta from the north, bringing single digit temperatures to areas north of Red Deer and a large band of precipitation behind it spanning the width of the province. Most of this precipitation has been falling as rain, but to the west, through Grande Cache and Grande Prairie, there has been light snow. The rain will transition to snow moving eastwards this evening and overnight as the temperatures continue to fall and a low pressure centre moves in from the west, pushing the front and its associated precipitation towards Saskatchewan.

South of this first round of snowfall, conditions will stay dry until late Monday morning when additional precipitation will push its way into the region from British Columbia, crossing eastward across Alberta through the afternoon and evening. With the passage of the expected low pressure centre and a second cold front, temperatures will actually drop throughout the day so a large swath of Southern Alberta will see precipitation start off as rain, but transition to snow later in the afternoon as the temperature continues to drop. The exception to this will be in the Rockies, where the precipitation is expected to fall predominantly as snow, leading to upwards of 20cm of snowfall accumulation.

Forecasting the exact amount of snowfall for this event has been tough because the temperatures will not fall too far below 0°C, only a few degrees in most places. Furthermore, the ground is still warm across much of the province, meaning that overall accumulation should be limited to just a few centimetres beyond the mountains. Despite this, roadways could still become slick, so make sure to exercise caution when travelling over the next couple of days.

Post-Thanksgiving Cool Down to Bring Season’s First Flurries to Parts of Southern Ontario on Tuesday

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The chill is definitely in the air following the Thanksgiving long weekend across Ontario, with overnight lows hovering around the freezing mark in many areas over the past few days.

This is a sharp change from the mild autumn weather we experienced throughout September, which has led to a noticeable delay in the changing of the leaves. While the trees are still taking their time to show off their fall colors, other signs of the season are on the way over the next few days.

Most notably, the combination of colder air and the warm waters of the Great Lakes will create ideal conditions for lake-effect precipitation to develop off Lake Huron and Georgian Bay.

While most areas will see lake-effect rain, it could get cold enough along the higher elevations of the Dundalk Highlands, south of Georgian Bay, for some wet flurries to appear on Tuesday.

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Additional precipitation is expected to move into Northeastern and Central Ontario by late Tuesday. As temperatures approach the freezing mark, some areas may see a transition to wet snow. However, significant accumulation is not expected, as the snow will likely melt almost immediately due to the warm ground, which remains above freezing.

For those who miss the milder weather, there’s no need to worry—there’s a warm-up on the way as we head into the weekend and early next week. Some areas could see daytime highs reaching the upper teens or even low twenties, which is well above the seasonal average for this time of year.

PRECIPITATION TYPE DURING THE DAY ON TUESDAY - MAP FROM WEATHERBELL

On Tuesday morning, most places will wake up to temperatures near the freezing mark, but daytime highs are expected to gradually rise into the mid to upper single digits. The higher elevations around Orangeville and Shelburne may struggle to climb above freezing, holding onto near-freezing temperatures throughout the day.

Lake-effect rain is expected to continue south of Georgian Bay throughout Tuesday, and some wet snow could mix in over the Dundalk Highlands during the day. This potential for flurries will be highly localized to the higher elevations between Owen Sound and Orangeville, while areas outside this region are likely to avoid the season’s first snowfall for now.

With temperatures hovering near or just above the freezing mark, significant accumulation is unlikely, as most of the snow will melt upon contact with the ground. However, there is a chance of a few wet, slushy centimeters in very localized areas.

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PRECIPITATION TYPE DURING TUESDAY night - MAP FROM WEATHERBELL

As we move into the evening and overnight hours, temperatures will again drop to near the freezing mark across Central, Eastern, and Northeastern Ontario. With scattered showers arriving from the north and east, there is a possibility that some of this precipitation could fall as wet flurries overnight and into early Wednesday morning.

Accumulation will remain a challenge due to the relatively warm ground. However, those in Huntsville, Algonquin Park, and the Ottawa Valley might catch a glimpse of their first snowflakes of the season. The chance of snow will diminish by late Wednesday morning as lake-effect precipitation weakens and any lingering showers move out of the region.

As mentioned earlier, we’re expecting a gradual warm-up for the rest of the week, though the mornings will still start off chilly, with temperatures in the single digits. The real warming trend will kick off on Friday, with temperatures climbing into the upper teens and possibly even approaching the low twenties in Southwestern Ontario and around the Golden Horseshoe.

This milder weather is expected to continue through the weekend and into early next week.

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

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

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

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

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

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

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

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

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

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

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

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

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

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