Snowy End to the Year for Southern Ontario With Accumulating Snow on New Year’s Eve

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The final month of 2023 has brought some unusual weather to Southern Ontario, marked by unseasonably warm temperatures and persistent fog enveloping much of the region over the past week.

This warmth led to an exceptionally mild Christmas across Southern Ontario, dashing hopes for a ‘White Christmas’ in all but the northern parts of Central and Eastern Ontario.

As the year draws to a close, there has been a noticeable shift back to colder weather, with temperatures dropping to near or below freezing over the last 24 hours. While this seems like a return to normalcy, it's worth noting that these temperatures are still slightly above average for this time of year, which is typically the beginning of the coldest period of the year.

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The cooling trend is accompanied by the potential for accumulating snow, courtesy of an Alberta Clipper moving across Southern Ontario on Sunday. This system is expected to deliver 2-4cm of snow to parts of Southwestern Ontario and the Golden Horseshoe, perfectly timed for the New Year's Eve countdown.

The snowfall will start late Saturday evening, initially light and possibly beginning as freezing drizzle, particularly east of Lake Huron. The drizzle should quickly give way to scattered flurries overnight.

By Sunday morning, we anticipate heavier snow bands moving in from the west, intensifying through the afternoon with snowfall rates of 1-2cm per hour, especially along the corridor from London through Kitchener to the Golden Horseshoe.

Steady snowfall is expected to continue into the evening, creating challenges for those travelling to New Year's Eve celebrations, with reduced visibility and slushy roads.

Due to the limited moisture associated with this clipper system, the snow should be contained to areas to the south of Lake Simcoe. This means that those in Central and Eastern Ontario likely won’t even see one snowflake from this system.

The snow is expected to taper off just before midnight, although flurries may persist into the early hours of 2024, ending by sunrise on Monday.

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The highest snowfall totals from this event are expected to be found across parts of Southwestern Ontario and around the Golden Horseshoe. Those in locations including London, Kitchener, Hamilton, Niagara and the Greater Toronto Area (GTA) can expect total snow accumulation to generally range from 2 to 4cm.

Some localized pockets could see upwards of 4-6cm since the snowfall distribution will be quite uneven as the system moves through. While those closer to the shoreline of Lake Ontario and Erie could fall short of the 2cm mark due to slightly warmer temperatures close to the lake.

For those in Deep Southwestern Ontario and southern portions of Central Ontario, you are looking at some light flurries occurring on and off throughout the day on Sunday. For most regions, this won’t even lead to any accumulation but some could still see a light dusting with up to 2cm of accumulation.

As mentioned, those further north in Central and Eastern Ontario aren’t expected to see any snow from this system.

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Looking towards the first week of 2024, it appears that the colder air is here to stick with us at least in the short term. This includes the potential for more rounds of snow throughout the week, but we aren’t expecting any significant accumulation at this point.

For those who enjoyed the mild start to winter, it looks like that is about to come to an end as we head back into more traditional winter-like weather for the start of the New Year.

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Winter Returns to Southern Ontario This Week With Heavy Rainfall Followed by Up to 15-20cm of Lake-Effect Snow by Tuesday

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It's hard to believe, but we're nearly a week away from Christmas Day, and most of Southern Ontario, except the snowbelt region, has yet to witness a significant snowfall this season. The little snow we've had quickly vanished, courtesy of the unusually mild start to December, with temperatures reminiscent of late fall or early spring.

However, a shift in the weather pattern is on the horizon as we approach the final week before Christmas, bringing the return of more conventional winter conditions. This change includes widespread snowfall expected between Monday and Tuesday, intensified by heavier lake effect snow bands around Lake Huron, Georgian Bay, and even Lake Ontario.

Temperatures are also poised to plummet, with much colder air sweeping across the province. We anticipate a brisk Tuesday morning, where, factoring in wind chill, it could feel like the negative teens or even lower, a stark contrast to the double-digit temperatures we've enjoyed on several days in recent weeks.

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Before Southern Ontario resumes its typical winter programming, a spell of milder weather is still holding on this weekend. As of Sunday afternoon, widespread rainfall is sweeping across the region.

Another bout of intense precipitation is set to hit Eastern Ontario overnight into Monday morning, courtesy of the outer precipitation bands of a potent system moving up the US East Coast. While the brunt of this storm will stay to our east, the trajectory does bring substantial rain to Extreme Eastern Ontario along the international border.

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Rainfall totals across Southern Ontario for Sunday are projected to be between 10 to 15mm, with some areas receiving up to 20 to 25mm. Eastern Ontario is expected to experience heavier rainfall, with accumulations of 30 to 50mm around Kingston, Ottawa, Brockville, and Cornwall. Locally, totals exceeding 50mm can’t be ruled out, particularly east of Ottawa.

The rain should recede across Southern Ontario by late Sunday evening, although Eastern Ontario may continue to experience heavy rain into Monday morning.

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Following the system to our east, a gradual cooling will ensue on Monday, with temperatures nearing the freezing mark later in the day, starting in Southwestern and Central Ontario.

Late Monday, a wave of weak precipitation is expected to track across Southern Ontario, beginning with light drizzle and transitioning to flurries as temperatures fall. There's some uncertainty regarding the intensity of this snowfall, as lake enhancement off the Great Lakes will primarily drive it.

Additionally, localized snow squalls are anticipated to develop off Lake Huron, Georgian Bay, and Lake Ontario, starting Monday evening and persisting into early Tuesday.

Steady snowfall is forecasted across Southern Ontario during the overnight hours and early Tuesday morning. While the heaviest snow will be concentrated near the lakes, it seems that even inland areas in Eastern and Central Ontario will see a light dusting.

Our focus is on areas south of Georgian Bay, Lake Huron, and parts of the Niagara region, where heavier snow bands are expected off the lakes.

The snow should taper off by Tuesday morning's end, though some lake-effect flurries might linger in the snowbelt regions.

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Current projections indicate the potential for 10 to 20cm of snow in two specific areas: south of Collingwood over the Blue Mountains off Georgian Bay and east of Sarnia around Petrolia and Lambton Shores, due to expected heavier lake effect snow overnight into Tuesday morning. Not everyone will experience such significant snowfall, as the bands will be narrow and unpredictable.

Heavier snow is also forecasted along the southern shoreline of Lake Ontario in the Niagara region, with 10 to 15cm possible between Grimsby and Niagara-on-the-Lake, while the rest of the Niagara region might see around 5cm.

Away from the lakes, the models are divided, with some higher-resolution models predicting less snow for Central and Eastern Ontario, while others suggest much more. We're currently estimating a general 5 to 10cm of snow, though actual totals will likely vary across the region.

Hence, some areas might exceed these predictions, especially in Eastern Ontario, while others may not reach the 5cm mark. The rest of Southern Ontario, including the GTA and Deep Southwestern Ontario, should expect a few centimetres of snow over the coming days.

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Snow Squalls Threaten Parts of Ontario Tuesday Into Wednesday; Locally Up to 25cm of Snow Possible

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While Southern Ontario has largely been spared significant snowfall this season, the lake effect snow machine is in full swing around Georgian Bay, Lake Huron, and Superior. The week began with heavy bursts of snow east of Lake Huron and along Georgian Bay's southern shoreline.

The focus now shifts northward, as a westerly flow initiates snow squalls late Tuesday, impacting areas east of Georgian Bay and adding to the squalls east of Lake Superior from Tuesday afternoon.

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By Wednesday afternoon, when the lake effect activity subsides, some areas could see 15-25cm of snow. These higher totals will be highly localized, depending on the squalls' exact positions. Even a slight wind shift could mean the difference between 0 or 25+ cm of snow.

Overnight into Wednesday, Parry Sound, Muskoka, and Northern Simcoe County will likely experience heavy snow and near-zero visibility. The snow bands could extend quite far inland, potentially affecting Haliburton and Kawartha Lakes, especially Wednesday morning. Later Wednesday morning, an intense snow band may move south, briefly hitting Grey-Bruce, Barrie, and northern GTA areas between 10 AM and 2 PM.

In the afternoon, a main squall off Lake Huron, near Port Elgin and Owen Sound, will stretch inland towards Shelburne and Orangeville. This is expected to dissipate by late afternoon but could reach parts of the GTA, possibly impacting the evening commute with a quick few centimetres of snow.

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The heaviest snowfall, between 15-25cm, is anticipated between Bracebridge and Orillia, depending on the squall's location.

Data suggests multiple squalls may occur, with a northern squall from Britt to Burk’s Fall and southern squalls affecting Southern Muskoka and Northern Simcoe County.

With the intensity of the lake effect activity spread out between the multiple bands, this should moderate totals, preventing extreme accumulation in a small area. Consequently, larger area east of Georgian Bay will experience snow squall activity, with widespread totals of 10 to 25cm.

Around Lake Huron, significant squall activity isn't expected, except for a brief squall near Port Elgin and Owen Sound on Wednesday afternoon, bringing 5-10cm, locally up to 15cm.

Central Ontario, particularly around Lake Simcoe and the northern GTA, could see up to 5-10cm from Wednesday's squall. Other parts of Southern Ontario not on the map will likely receive less than 2cm.

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East of Lake Superior, lake-effect snow will persist this evening into the overnight between Wawa and Sault Ste. Marie. The squalls are expected to weaken Wednesday morning as wind direction shifts, ending the lake-effect snow.

Similar localized snowfall of 15-25cm is expected by Wednesday afternoon in the Sault Ste. Marie and Wawa area. Accumulation will decrease quickly away from Lake Superior's shoreline, though Elliot Lake could see up to 5-10cm from the inland-reaching squalls tonight.

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Snow Squalls Return to Southern Ontario’s Snowbelt This Week With Up to 10-15cm of Snow by Late Monday

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December kicked off on a messy note with a winter storm bringing snow and prolonged freezing rain to parts of the Ottawa Valley. However, the last few days have treated us to record-breaking warmth, with many locations across Southern Ontario registering double-digit temperatures on Saturday.

This weather roller coaster is expected to persist as we enter the second week of December. This time, we anticipate more typical winter conditions, featuring a near-miss snowstorm in Eastern Ontario and a resurgence of lake-effect snow activity around Georgian Bay and Lake Huron.

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There has been much discussion about a potential system this weekend that, at one point, seemed likely to bring significant wintry weather to parts of Southern Ontario.

While we've been closely monitoring it, the models presented too much uncertainty and disagreement to even attempt a forecast. It is now evident that this system will track far to the east, crossing over the US Northeast and into Quebec, where 15-30cm of snow is possible tonight and throughout Monday.

Recently, attention has focused on whether there might be slight adjustments to the west, potentially bringing heavy snowfall to parts of Eastern Ontario. As of now, this western track hasn't materialized in the models, and some have even shifted it further east.

We could still see a few centimetres of snow along the US border in Eastern Ontario, including Brockville and Cornwall, during the day on Monday. However, it will likely max out at around 5cm, possibly locally as much as 7cm, but that remains uncertain.

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In addition to the system snow, we are closely monitoring the potential for disorganized lake-effect snow bands to develop off Georgian Bay and Lake Huron late Sunday evening. The heaviest lake-effect activity appears focused on the southeastern shoreline of Georgian Bay and Lake Huron.

Localized snow squalls will persist throughout Monday. While the activity is expected to remain fairly disorganized and spread out, even weak lake-effect snow has the potential to reduce visibility. Strong wind gusts between 30-50 km/h could cause blowing snow, so it's essential to drive according to the conditions!

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By the time the squalls fizzle out on Monday evening, the hardest-hit regions, including Collingwood, Wasaga Beach, Angus, Wingham, Goderich, Clinton, Mitchell, and Stratford, could see snowfall totals ranging from 5-10cm.

There's a possibility that a few localized totals could approach 15cm if the lake-effect bands are more intense than expected. However, this depends on the exact location of the squalls, and not everyone within the 5-10cm zone will see that much snow!

For surrounding regions southeast of Lake Huron and Georgian Bay, we anticipate up to 5cm of snow over the next 24 hours. Local totals could be slightly higher if the squall activity stretches further inland. Some light snow will move across northern parts of Central Ontario early Monday, leading to snowfall totals of around 2-5cm.

For the rest of Southern Ontario, expect a few brief bursts of lake-effect flurries throughout Monday, but it won't lead to any notable accumulation.

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Potential Winter Storm for Central and Eastern Ontario Including Ottawa; 15-25cm of Snow & Freezing Rain Starting Sunday

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While the winter weather season has been quite active in most of Southern Ontario over the past few weeks, Eastern Ontario has largely been spared from the worst of it. However, that streak of luck is about to change as the first significant winter storm is on the horizon, set to begin on Sunday.

Current data indicate that the Ottawa Valley may experience widespread snowfall totals ranging from 15 to 25cm between Sunday afternoon and Monday morning. There is even a possibility of some localized totals exceeding 25cm, though this is expected to be fairly isolated.

Central and Eastern Ontario are also facing the concern of freezing rain, with locally up to 5-10mm of ice accretion possible, while more widespread amounts will be closer to a few millimetres of ice.

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The system responsible for this wintry mix is poised to move into our region early on Sunday, initially bringing a combination of freezing rain and snow to Central and Eastern Ontario. As the day progresses, it will transition into more sustained heavy snow, with the most challenging conditions anticipated late Sunday into early Monday morning.

There is also a possibility of freezing rain to the northwest of the Greater Toronto Area, particularly over the higher elevations of the Dundalk Highlands during Sunday morning and afternoon.

For Southwestern Ontario and the Lake Ontario shoreline, precipitation is expected to remain mostly rain throughout the event, with limited impact. However, there could be a transition to wet flurries overnight into Monday morning as the system moves out and colder air follows.

By the evening, freezing rain is likely to transition to heavy snow as colder air settles across the region. This brings the potential for rapid snowfall accumulation in the Ottawa Valley and northern parts of Central Ontario during the evening and early overnight hours.

Hourly snowfall rates might briefly approach 4-8cm at the peak of this event, coupled with 50-70km/h wind gusts, leading to blowing snow and near-zero visibility on roads. Travel is strongly discouraged starting late Sunday into early Monday. We will likely see some school bus cancellations on Monday morning.

Snowfall will persist into early Monday morning, gradually coming to an end by sunrise. Flurries are expected to linger throughout the morning, but significant accumulation is not anticipated.

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Regarding the freezing rain threat, there are two areas of concern with the heaviest freezing rain potential. The first is confined to the higher elevations around the Dundalk Highlands, including Orangeville and Shelburne.

Moving eastward, the freezing rain threat becomes more widespread, covering most of Eastern Ontario and Central Ontario. However, a quicker switch to snow may result in less actual ice accretion than initially forecast.

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The highest ice accretion is expected southwest of Ottawa, including Smiths Falls, Bancroft, Kaladar, Arnprior, Orangeville, and Shelburne. This region could see up to 5-10mm of ice by the end of Sunday.

Those in Cornwall, Ottawa, and areas westward into Muskoka may experience a few millimetres of freezing rain primarily during the early part of Sunday before transitioning to heavy snow by Sunday evening.

A critical aspect of this event is its potential impact due to the absence of a substantial warm-up after the freezing rain, which could impede the melting of any ice that forms. Above-freezing temperatures may not return to the region until next weekend at the earliest, ensuring that the ice and snow will linger.

Compounding the situation, heavy snowfall is expected, raising the risk of power outages as accumulated ice and snow will weigh down power lines and tree branches.

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The highest snowfall totals are expected along the Quebec border, including Hawkesbury, Ottawa, Arnprior, Renfrew, and Pembroke. Accumulation in this area is projected to range from 15 to 25cm, with the potential for a few locations to exceed 25cm, particularly over the higher elevations west of Ottawa.

A zone extending from Cornwall through Smiths Falls and into Bancroft can expect around 10-20cm of snow from this storm. This region, experiencing the worst freezing rain impact, may be one of the hardest-hit areas from the combined effects of ice and snow.

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To the west, widespread totals ranging from 5 to 10cm are expected, extending from Eastern Ontario westward to areas around Lake Simcoe and Georgian Bay. Some models suggest possible lake enhancement off Georgian Bay, leading to locally higher totals of up to 15cm in parts of Simcoe County and Muskoka.

Less than 5cm of snow is anticipated around the Lake Ontario shoreline and in Southwestern Ontario, where precipitation will primarily be in the form of rain. Rain accumulation is expected to range from 5-15mm, with some areas around Lake Ontario, including Toronto eastward into Kingston, possibly seeing up to 15-25mm.

Snowy Start to the Weekend for Southern Ontario With Up to 5-10cm of Snow Late Friday Into Saturday

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December has arrived, and Mother Nature is swiftly ushering in winter across Southern Ontario. Earlier this week, we witnessed the first significant lake-effect event of the season, blanketing parts of the snowbelt region around Lake Huron and Georgian Bay with over 30cm of snow.

As we step into the first weekend of December, it is set to begin on a snowy note for much of Central and Eastern Ontario, courtesy of a system tracking across the region today into Saturday. Precipitation has already started in the southwest part of the province and is anticipated to persist throughout the evening and into Saturday morning.

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For Southwestern Ontario and the Golden Horseshoe area, we anticipate predominantly rain persisting intermittently over the next 24 hours. However, we could see some wet flurries mixed in around parts of the GTA. Total rainfall accumulation is projected to range from 5 to 15mm.

The focus of the weather story shifts northward, especially across the higher elevations of the Dundalk Highlands into Central and Eastern Ontario. These areas have already seen some wet flurries this afternoon which is expected to intensify later in the day and overnight.

This snowfall won’t be excessively heavy, with more prolonged steady, light to moderate snowfall throughout the evening and overnight hours, stretching from Georgian Bay through Central Ontario into the Ottawa Valley. It will gradually subside just after sunrise and should conclude around the noon hour.

There's also a potential risk of freezing drizzle to the northwest of the GTA, encompassing Orangeville and Shelburne overnight. However, its impact is likely to be insignificant, and not every model supports this scenario.

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The highest snowfall accumulation from this event is expected to be between 5 and 10cm by Saturday afternoon. This encompasses regions such as Orangeville, Barrie, Muskoka, Bancroft, Renfrew, and Pembroke. While most locations are likely to fall closer to the 5cm mark, a few localized areas could approach or even exceed 10cm.

Ottawa, Peterborough, Newmarket, Guelph, and Kincardine may experience a few centimetres of snow, while the rest of Southern Ontario anticipates less than 2cm, with wet flurries possible around the Lake Ontario shoreline into the Kitchener region.

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Snow Squall Threat Continues Into Wednesday in Parts of Southern Ontario With an Additional 10 to 20cm of Snow Possible

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It has been an active start to the week around Lake Huron and Georgian Bay, with intense snow squall activity bringing significant snowfall accumulation and near-zero visibility.

Some locations have already witnessed upwards of 20-30cm of snow over the last two days, with the anticipation of snow squalls to drift back north to regions east of Lake Huron and Georgian Bay late Tuesday. Another day of snow squalls is expected on Wednesday; however, they won't be as intense as Tuesday’s squalls and will affect areas further north.

Additional snowfall over the next 24 hours, between Tuesday and Wednesday evening, could range from 10-20cm in the hardest-hit regions. As some locations have already seen 20-30cm of snow from earlier squalls, overall snowfall totals since Sunday could approach 30-40cm!

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The main snow squall band of Lake Huron currently stretches from Goderich through Perth County and into the Woodstock area. Meanwhile, the Georgian Bay squall is hammering the Wasaga Beach, Barrie, and Keswick areas.

This will persist for a few more hours into the early evening before we expect a shift in the wind direction to a more westerly to southwesterly flow overnight.

As the winds shift, this will cause the snow squall activity to drift northwards, with the Lake Huron squall moving into the Grey-Bruce region and the Georgian Bay squall targeting the Muskoka and Parry Sound regions.

Expect poor driving conditions mainly east of Georgian Bay, along with the Bruce Peninsula throughout the morning on Wednesday. Another day of school bus cancellations is likely due to rapid snowfall accumulation and reduced visibility.

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It appears that the snow squalls on Wednesday will be somewhat more disorganized compared to what we saw from Monday evening into Tuesday. A wide swath of the eastern shoreline of Georgian Bay from Sundridge down to Gravenhurst will experience moderate to heavy snow into Wednesday afternoon.

By Wednesday afternoon, the activity could briefly become more organized into what could be a strong squall stretching from Parry Sound into the North Bay region, although it likely will only last for a few hours. Scattered lake-effect snow will continue throughout the rest of Wednesday, tapering off fully by the evening.

Due to the shift in wind direction, there could be a heavy burst of snow across the GTA and Eastern Ontario late Wednesday as the remnants of the snow squalls slide to the southeast. This won’t have much of a significant impact but could bring a fresh dusting of snow.

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While the more spread-out lake-effect activity will help avoid any major accumulation in a focused region, this will result in a larger area seeing some notable accumulation over the next 24 hours.

General snowfall totals should end up between 10 to 20cm in regions including the Bruce Peninsula, Owen Sound, Hanover, Kincardine, Wingham, Listowel, Parry Sound, and Muskoka. It’s possible a few areas could approach 25cm in localized pockets. This is on top of the previous snowfall from the last two days in these areas.

Surrounding regions inland from Lake Huron and Georgian Bay can expect around 5-10cm of additional snowfall, with perhaps as much as 15cm in localized areas. Keep in mind that this is less certain as it will depend on the exact strength and location of the snow squalls.

Less than 5cm is expected for the rest of Southern Ontario, with most of that coming late Wednesday as the decaying snow squall slides through.

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Snow squalls are also expected to return to areas southeast of Lake Superior by Tuesday evening and continue through Wednesday. The hardest-hit area appears to be the corridor between Wawa and Sault Ste. Marie. Between 10 to 20cm of snow is possible by the end of Wednesday.

Further north, a weak system will slide across Northwestern Ontario late Wednesday, bringing up to 5-10cm of snow to areas around Thunder Bay and to the northwest towards the Manitoba border.

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Snow Squalls Could Bring ‘Blizzard-like’ Conditions and Bury Parts of Ontario in Up to 50cm of Snow Between Sunday and Tuesday

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Confidence is growing in a significant snow squall threat to kick off the week in the regions around Lake Huron, Georgian Bay, and Lake Superior. Snow squall activity is anticipated to start as early as Sunday evening and persist through Monday into Tuesday.

These squalls will bring the potential for rapid snowfall accumulation, with hourly rates reaching 5-10cm. Combined with strong wind gusts, it is likely to result in blowing snow, possibly even leading to localized blizzard-like conditions.

Road closures are likely, especially late Monday into Tuesday morning when the most severe conditions are expected. The highest impact from this snow squall event will extend through the corridors from Owen Sound to Goderich and Orillia to Huntsville. For Northern Ontario, the Sault Ste. Marie and Wawa area will bear the brunt of the snow squalls off Lake Superior.

Total snowfall accumulation over the next few days will be highly variable, depending on the precise location of narrow yet intense bands of lake-effect snow. These bands are expected to shift around, limiting extreme totals but affecting a wider area at some point over the next 3 days.

Combined snowfall accumulation by Tuesday evening could approach 40-50cm in localized areas. General totals throughout the typical snowbelt region will range from 15 to 30cm.

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SUNDAY

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This multi-day snow event begins Sunday evening as a messy system is currently tracking across the province. For most of Southern Ontario, precipitation has been a mixed bag, including rain, freezing rain, ice pellets, and wet snow throughout the afternoon and evening.

Limited snowfall accumulation is expected on Sunday, except for areas east of Lake Huron and Georgian Bay. Lake enhancement could boost snowfall totals to 5-10cm (locally 15cm) by nightfall for the Grey-Bruce, Parry Sound, and Muskoka regions.

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Northeastern Ontario will also see some notable snowfall accumulation, with widespread accumulation of 10-15cm by Sunday's end. A small zone east of Lake Superior between Wawa and Sault Ste. Marie could experience higher totals of up to 20-25cm due to evening snow squalls.

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MONDAY

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The lake effect snow machine ramps up early Monday with squalls developing off Lake Huron and Georgian Bay. There's model disagreement on the exact squall direction, but a westerly flow is expected initially.

The lake-effect snow will likely be disorganized and spread out initially, with bands developing across Lake Huron, crossing the Bruce Peninsula and Georgian Bay before coming onshore between Parry Sound and Port Severn.

This continues into the afternoon, with activity becoming more focused, affecting parts of Muskoka and Parry Sound. The location of the strongest squall is unclear, with one model suggesting Parry Sound to Huntsville, while another places it further south, focusing on the Port Carling and Bracebridge region.

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Local snowfall amounts by Monday's end could range from 15 to 25cm, although the localized nature of these squalls means not everyone will see that much snow. Bracebridge, Port Carling, Port Sydney, Rosseau, Huntsville, and Parry Sound are included.

Additional lake effect activity is expected east of Lake Huron, with heavier snow away from the shoreline. Locally, 10-15cm, possibly even 20cm, is possible in Listowel, Hanover, and Chatsworth.

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Sault Ste. Marie will likely face snow squalls starting early Monday and lasting throughout the day. Local amounts could approach 20cm in the hardest-hit regions by Monday's end.

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TUESDAY

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A shift in wind direction late Monday will cause the snow squalls to sink southward overnight into early Tuesday, intensifying further. The worst conditions are expected during the pre-dawn hours on Tuesday, with blizzard-like conditions making travel near impossible throughout a big chunk of the snowbelt east of Lake Huron and southeast of Georgian Bay.

The squalls become stationary again by late Tuesday morning, with one main squall off Georgian Bay and coming onshore somewhere between Orillia and Barrie. This squall may stretch far inland, bringing heavy snow to parts of the Kawartha Lakes and the northern Durham region.

Two main squalls off Lake Huron will be present, with the more northern band stretching from Port Elgin inland towards Hanover and Shelburne. Further south, a secondary squall will come onshore between Point Clarke and Goderich, stretching into the Listowel and Mitchell area.

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Again, the overall accumulation will depend on exactly where these bands lock-in, but the heaviest snowfall will likely be found in locations including Point Clark, Wingham, Listowel, Port Elgin, Hanover, Wasaga Beach, Midland, and Port Severn by Tuesday's end. These areas have the potential for snowfall totals ranging from 20 to 30cm, with locally higher amounts not out of the question.

Surrounding regions east of Lake Huron and around Lake Simcoe can expect 10 to 25cm, depending on the squalls' location and how far they stretch inland. Even parts of the Greater Toronto Area (GTA), particularly in the west end, could see a quick 5-10cm with the snow squalls off Lake Huron.

The Tuesday forecast should be considered preliminary as we await developments on Monday. Adjustments might be necessary as more higher-resolution model data become available.

Snow squalls may persist into Wednesday, although it's unclear which regions could be affected; this will be covered in a separate forecast.

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OVERALL IMPACT

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With the snow squalls expected to shift over the next few days, extreme accumulation usually associated with stationary squalls is less likely. However, this will allow for a more widespread impact as the snow is more spread out.

An expansive zone east of Lake Huron from Owen Sound to Listowel could see 3-day snowfall totals between 25-40cm, locally up to 50cm. The story is similar to the eastern shoreline of Georgian Bay, with Parry Sound, Muskoka, and Northern Simcoe County in the bullseye.

Away from these areas, expected accumulation drops off rapidly, subject to more uncertainty depending on how far inland the squalls extend.

Around 15 to 30cm is possible for locations including Goderich, Stratford, Wiarton, Meaford, Barrie, Orillia, Lindsay, and Haliburton. Regions just west of the Golden Horseshoe, including Kitchener, Guelph, and Brantford, could see locally up to 10-20cm if the snow squall activity reaches them.

Again, not everyone will see significant totals, and some may not see any snow, given the extremely localized nature of these bands. It's challenging to pinpoint exactly where the squalls will end up.

Less than 5cm of snow is expected for most of the Golden Horseshoe, Eastern Ontario, and Deep Southwestern Ontario throughout the next 3 days.

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In Northern Ontario, widespread snowfall totals between 10-20cm are expected on Sunday night and Monday.

More intense snowfall is expected along the eastern shoreline of Lake Superior, with 25-40cm possible between Wawa and Sault Ste. Marie due to expected snow squall activity on Monday.

First Strong Snow Squall Event of the Season Could Bring Significant Snowfall to Parts of Southern Ontario Starting Sunday

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Winter is settling in across Ontario as we approach the end of November, and early next week marks the arrival of the coldest air so far this season, featuring temperatures well below the freezing mark.

By Tuesday, some parts of Northern Ontario, as well as the northern sections of Southern Ontario, could experience double-digit negative temperatures, even before factoring in the wind chill.

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This frigid blast of cold air is triggering what appears to be a robust lake effect snow event in the traditional snowbelt region around Lake Huron, Lake Superior, and Georgian Bay. Locally intense snow squalls are anticipated to develop from Sunday evening, persisting through Monday and into Tuesday.

A potential secondary round of snow squalls may emerge starting Wednesday, though the exact location and intensity remain uncertain, which will be covered in a separate forecast in the coming days.

While still a few days away, most models are converging on a general consensus regarding the hardest-hit regions of these squalls, primarily driven by a northwesterly flow. However, variations in expected accumulation will become clearer as higher-resolution models come into view.

On Sunday, a weak system is forecasted to track through Southern Ontario, bringing some flurries and mixed precipitation across the region. Nevertheless, any snowfall accumulation is expected to be minor, with only a few centimetres possible.

As the system exits the region by late Sunday, colder air from the north will usher in lake-effect snow off Georgian Bay and Lake Huron as early as Sunday evening. Initially disorganized, the lake effect activity is likely to focus on areas northeast of the lake, with the Bruce Peninsula and Parry Sound region experiencing locally heavy snow.

By Monday morning, the lake effect snow will shift southward, intensifying as the environment becomes more favourable for snow squalls.

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Current indications suggest two distinct squalls, with one stretching across the Bruce Peninsula, over Georgian Bay and coming onshore between Barrie and Orillia. A secondary squall is expected further south, predominantly affecting the Port Elgin, Owen Sound, Hanover, and Kincardine regions.

There is potential for these squalls to persist for up to 12-16 hours starting Monday afternoon and continuing into Tuesday morning. The exact location of the squalls is challenging to pinpoint at this stage, dependent on wind direction, strength, and temperature. If they lock in place, locally intense snowfall rates may lead to rapid accumulation and hazardous road conditions due to near-zero visibility, accompanied by blowing snow.

The snow squalls may continue into Tuesday, with the most intense conditions likely between Monday evening and Tuesday morning, gradually improving throughout the day. A shift in wind direction by Tuesday evening may temporarily halt the lake effect, but squalls could return overnight into Wednesday, focusing on regions southeast of Lake Huron, including Grand Bend and even London.

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We've outlined a rough idea of where the worst impacts from the lake effect snow are expected between Monday and Tuesday. Please note that this is preliminary, and the forecast zones will be refined in the coming days as higher-resolution models become available.

Regions in the strong impact zone include Port Elgin, Chatsworth, Owen Sound, Hanover, Flesherton, Midland, and Simcoe County. Some locations within this zone could see hefty snowfall totals approaching 25 or even 50cm.

The rest of the regions east of Lake Huron and Georgian Bay can expect a moderate impact from snow squall activity, with up to 25cm of snow possible. The Georgian Bay squall may extend quite far inland at times, affecting parts of Durham region and Kawartha Lakes.

While lake effect activity off Lake Ontario and Erie is expected to remain mostly stateside, it could briefly drift north late Tuesday, leading to heavy snow in the southern part of the Niagara region and Prince Edward County. Locally, 5-10cm of snow is possible within a few hours.

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Turning our attention to Northern Ontario, snow squall activity off Lake Superior is anticipated to be relatively weaker than those off Georgian Bay and Lake Huron. However, we could still see up to 25cm throughout the Sault Ste. Marie and Wawa area, primarily on Sunday and early Monday.

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Snow Squalls Could Bring Over 10cm of Snow to Parts of Ontario’s Snowbelt on Friday

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The chill is set to descend upon Ontario to wrap up the week, heralding the return of lake-effect snow in the traditional snowbelt on Friday. Some regions surrounding Lake Huron, Superior, and Georgian Bay could experience accumulations of over 10cm from the snow squall activity before it diminishes late Friday.

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Lake-effect snow has already materialized off Lake Superior in Northern Ontario as of Thursday evening, accompanied by temperatures well below freezing. This trend is expected to persist overnight and into Friday, primarily affecting areas southeast of the lake, including Sault Ste. Marie.

Heading further south, temperatures are still above the freezing point, but this is anticipated to change in the coming hours. Lake-effect snow is expected to commence around midnight, likely remaining relatively unorganized for much of the night.

Current indications suggest the heaviest snowfall will be concentrated in Grey, Bruce, and Simcoe counties, with the activity becoming more organized by early Friday morning. Localized snow squalls are expected to persist throughout the morning and afternoon hours.

The Lake Huron squall is projected to come onshore around Point Elgin and extend inland towards Hanover, while the Georgian Bay squall will focus on the Wasaga Beach, Barrie, and Angus areas. However, it may extend into parts of the Northern Greater Toronto Area (GTA) at times.

Activity off Lake Superior should taper off by late Friday afternoon. However, around Lake Huron and Georgian Bay, lake-effect snow may linger into the evening and potentially even early Saturday morning before tapering off just after midnight. The most intense activity is expected during the morning and afternoon.

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As is typical with a lake-effect event, snowfall totals will vary considerably, depending on the exact placement of the squalls and their duration over a particular area. Our forecast predicts a general 5-10cm in locations including Port Elgin, Chatsworth, Hanover, Wasaga Beach, Angus, and Barrie.

There's potential for a few localized regions to accumulate up to 15cm, as one model, in particular, is aggressive with squall intensity. Conversely, some regions may struggle to reach the 5cm mark due to the localized nature of lake-effect snow.

Between 2-5cm of snow is possible for surrounding regions, including those northeast of Lake Huron and around the southern shoreline of Georgian Bay.

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This potential also extends into parts of York Region due to the Georgian Bay snow squall occasionally reaching that far inland, although it isn't guaranteed, and the lake-effect snow may stay closer to the shoreline.

A few flurries are possible for the rest of Southwestern and Central Ontario, including much of the GTA away from the lake. No accumulation is expected, as there won't be enough snow to stick to the ground.

The scenario is similar off Lake Superior, with our forecast calling for between 5-10cm for locations, including Sault Ste. Marie. Again, some locations could exceed that, with upwards of 15cm possible. A few centimetres of snow are possible for the rest of the eastern shoreline of Lake Superior.

UPDATE: Ontario’s Wintery Blast of Freezing Rain & Snow Starting Wednesday Is Trending Stronger

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Concern is growing for what could be a disruptive freezing rain event for parts of Southwestern, Central and Eastern Ontario between Wednesday and Thursday. Heavy snow and ice pellets to the north may bring up to 20cm of snow to parts of Northeastern Ontario by the end of Thursday.

The latest model data indicates a more extensive and impactful freezing rain risk than initially anticipated in our previous forecast. As a result, we have made adjustments to our freezing rain forecast to align with these new developments.

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We have already received reports of some ice accretion in parts of Southwestern Ontario early Wednesday afternoon. Freezing rain is projected to continue spreading across Southwestern Ontario throughout the afternoon. Current ground observations reveal a persistent pool of cold air at the surface in much of the region.

As heavy rainfall currently positioned over Michigan advances into our area, there is a growing concern of significant icing over the next 6-12 hours, with temperatures hovering just below the freezing point.

The higher elevations northwest of the Greater Toronto Area (GTA), including Shelburne and Orangeville, are expected to bear the brunt of freezing rain from this event. Freezing rain will start within the next few hours and may persist into the early overnight period before transitioning to rain.

Additionally, we are also expecting strong wind gusts approaching 60-80km/h late Wednesday into early Thursday. This combined with the freezing rain could lead to power outages in the regions that see significant ice accretion today.

Our forecast for this region has been upgraded to 10-15mm of ice accretion. However, accurately estimating how much of the rain will adhere to surfaces remains challenging, as it could fall rapidly at times.

In the surrounding areas, such as Kitchener, Guelph, Owen Sound, and regions east of Lake Huron, a few hours of freezing rain are expected this afternoon and early evening. It should change to regular rain shortly after dinner. The total ice accretion in these areas will range from 2-5mm, with the potential for up to 5-10mm in higher elevations, including Fergus, Listowel, and Hanover.

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As we progress into the overnight hours, our focus will shift to the north and east, with a secondary area of freezing rain set to develop just before midnight across Central and Eastern Ontario. This is likely to continue into Thursday morning, potentially leading to school bus cancellations - further details will be available in our first 'ice day' forecast of the season tonight.

The freezing rain forecast for Central and Eastern Ontario carries some uncertainty due to the presence of ice pellets and snow mixing with freezing rain. The area hardest hit appears to be east of Lake Simcoe, with an expected 5-10mm of ice for Kawartha Lakes and Peterborough.

An extensive zone spanning from Muskoka through the Ottawa Valley should anticipate around 2-5mm of freezing rain. Less freezing rain is expected further north, where snow and ice pellets will take precedence.

It's important to note that the inclusion of ice pellets in Central and Eastern Ontario may lead to reduced ice accretion. This is shown on our map in the orange hatched outline where we expected ice pellets could reduce the ice accretion.

We anticipate that the wintry weather across Southern Ontario will subside by early Thursday afternoon as the system departs the region.

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The story further north across Northeastern Ontario will be about the heavy snow starting Wednesday evening. This snow will continue overnight and linger throughout the day on Thursday. We expect that the worst conditions will be felt during the morning hours on Thursday with the heaviest snowfall rates.

As the snow comes to an end by Thursday evening, some parts of Northeastern Ontario could be looking at between 15-20cm of snow on the ground. This includes Chapleau, Timmins, Kirkland Lake and Temiskaming Shores. It isn’t out of the question that some locally higher totals of up to 25cm could occur within this region.

For the rest of Northeastern Ontario, you can expect between 10-15cm of snow along with some ice pellets for locations around Georgian Bay including Sudbury and North Bay. Less than 10cm of snow is expected across Northwestern Ontario so we haven’t included them in this forecast.

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The mixing line with this system will likely set up somewhere in the northern section of Central and Eastern Ontario. As a result, the potential for snow extends southwards into parts of Southern Ontario. We are expecting the highest totals through Sundridge and Algonquin Park with between 10 to 15cm of snowfall accumulation.

Around 5 to 10cm of snow is on tap for Huntsville, Bancroft and the Ottawa Valley including the City of Ottawa. Lower amounts are expected further south where freezing rain will be the focus. Between 2-5cm of snow is possible for Bracebridge, Smiths Falls and Cornwall. A few wet flurries are likely across the Golden Horseshoe and around Lake Simcoe this afternoon before it switches over to ice pellets and freezing rain.

Similarly to the freezing rain, ice pellets could also affect the overall snowfall totals. Especially in Central and Eastern Ontario where models disagree on the extent of ice pellets mixing in with the snow. More ice pellets would likely lead to lower snowfall totals in this area.

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Messy Commute Ahead: Prolonged Freezing Rain Risk in Parts of Southern Ontario Starting Wednesday Afternoon

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UPDATED FORECAST:

OLD FORECAST:

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Ontario has seen an early onset of winter weather with multiple snowfalls, yet the first true ‘winter storm’ has been absent—until now. A complex wintery mix looms, set to deliver a blend of freezing rain, ice pellets, and heavy snow to parts of the province beginning Wednesday.

A system from the US Midwest will arrive in Ontario by Wednesday afternoon. As the initial bands of precipitation first reach Southwestern Ontario, the rain will meet a pocket of cold air at ground level, leading to the formation of freezing rain.

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The higher terrain of Southwestern Ontario, just northwest of the Greater Toronto Area (GTA), could face extended periods of freezing rain, peaking during the evening rush hour.

Locations like Guelph, Kitchener, Hanover, and Orangeville might see freezing rain lasting throughout the late afternoon and early evening.

Areas around Lake Simcoe are also in the bullseye for a mix of freezing rain, ice pellets, and wet snow starting early in the evening.

Overnight, temperatures are predicted to climb, transitioning the freezing rain in Southwestern Ontario to plain rain, while Eastern and Central Ontario will likely see snow and ice pellets.

By Thursday morning, however, the southern portion of Central/Eastern Ontario—stretching from Muskoka through Bancroft to the Ottawa Valley—may experience some freezing rain.

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Our forecast splits the difference, with up to 5-10mm of ice accumulation in the Dundalk Highlands and east of Lake Huron, with 2-5mm possible in the northern GTA, around Lake Simcoe, and towards Peterborough.

Light icing is likely across Central and Eastern Ontario with freezing drizzle during Thursday's early hours. Remember, ice accumulation will depend on the precise temperatures and how swiftly they rise past freezing. Given the short duration, the impact should be more limited.

Yet, even this amount of ice can cause treacherous roads and power outages, not to mention the potential for school bus cancellations, especially in Central and Eastern Ontario, where conditions will remain challenging into Thursday morning.

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Northeastern Ontario is set to see primarily snowfall, with ice pellets likely near Sudbury and North Bay. Snowfall begins late Wednesday and continues into early Thursday, with the heaviest snow expected overnight at rates of 2-3cm per hour.

Initial data showed Northeastern Ontario could receive up to 30cm of snow, but recent updates suggest a more manageable 10-15cm for Sudbury, Chapleau, and Temiskaming Shores. Elsewhere in Northern Ontario, from Thunder Bay to the Manitoba border, 5-10cm is forecasted.

Moving south into Central and Eastern Ontario, less snow is anticipated. Algonquin Park and northern Central Ontario may still see a notable accumulation of 5-10cm with ice pellets, while less than 5cm is expected for the remainder of these regions.

Rain is on the menu for Windsor, Chatham, Sarnia, London, and the Golden Horseshoe, which will sidestep the winter conditions. Come Thursday, they can expect 10-20mm of rain, with potential for higher localized totals.

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Snow Squalls Could Bring a Frightening 15-25cm of Snow to Parts of Southern Ontario on Halloween Night

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Many across Southern Ontario received a chilling surprise this morning: a blanket of snow. Notably, areas around Lake Huron and Georgian Bay saw accumulations thanks to the active lake effect snow from the past 24 hours.

However, Mother Nature isn’t done playing her snowy tricks, as snow squalls are predicted to make a comeback later today. In fact, lake-effect snow off Georgian Bay is already affecting the Parry Sound region this afternoon.

These snow bands will persist into the evening off Georgian Bay, but a wind shift around midnight will divert this lake effect activity southward. This means a brief but intense bout of snowfall for Muskoka and Simcoe County between 10 PM and 1 AM.

If you're travelling in this area tonight, exercise caution: these squalls can dramatically reduce visibility within seconds!

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Another round of lake effect snow from Lake Huron may result in heavy snowfall from Goderich through Kincardine to the Owen Sound region, primarily in the evening and early hours, shifting south after midnight.

As the night progresses, the snow activity off Georgian Bay appears to weaken, leaving some lingering flurries near Meaford and Collingwood. On the other hand, the squalls from Lake Huron may intensify before dawn on Wednesday.

Current data suggests this main band will target the southeastern shoreline of Lake Huron, especially from east of Sarnia through Lambton Shores to Grand Bend. This region may bear the brunt of the lake effect activity from late night to Wednesday morning.

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There is some uncertainty about the exact location and intensity of the lake-effect snow. It could potentially be strong leading to heavy snowfall rates lasting several hours between Sarnia and Grand Bend. Wednesday morning might pose challenging driving conditions, with a possibility of localized school bus cancellations.

By Wednesday noon, the organized lake effect snow should dissipate. Some residual flurries east of Lake Huron might linger, but no significant accumulation is anticipated.

As typical with lake effect events, the heaviest snowfall will be localized. Current model data shows a pocket between Sarnia and Lambton Shores could see up to 25cm by Wednesday afternoon.

We're forecasting 15-25cm, but it’s crucial to understand the unpredictable nature of lake-effect snow. We’re confident someone in this zone will approach 25cm, depending on the squall’s precise path. But not everyone will see that much snow and even some may see only a few centimetres as the squall will be very narrow.

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For areas northeast of Georgian Bay, up to 10-20cm is expected around Parry Sound and Sundridge, mostly falling this afternoon and evening. Surrounding regions east of Lake Huron and south of Georgian Bay might see 6-12cm, depending on the location of the lake effect activity

Central Ontario regions like Muskoka and Simcoe County could receive about 4-8cm, primarily over the period of a few hours late tonight as the squalls move south.

For the rest of Southern Ontario, significant accumulation is unlikely. However, some scattered lake effect flurries tonight and early tomorrow are possible, but it won't be widespread and more likely the closer you are to Lake Huron or Georgian Bay.

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Spooky Snow Set to Haunt Ontario With Up to 15-25cm Possible by Tuesday

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October in Ontario has been a mix of tricks and treats. While we've basked in some unseasonably warm "treats" this month, including record-breaking highs last week, it seems Mother Nature might have a little "trick" up her sleeve just in time for Halloween.

This unexpected surprise will unfurl as widespread snowfall, starting early Monday and stretching into Tuesday, with some lake-effect snow hauntings around Georgian Bay, Lake Huron, and Lake Superior. By the time trick-or-treaters venture out on Halloween evening, some parts of Ontario might be walking through a 15-25cm blanket of ghostly white snow!

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Ontario's current chilling touch is a prelude to what lies ahead. A system is breezing through Southern Ontario, mainly shedding tears of rain, but there've been whispers of sleet in some corners. Temperatures are expected to take a ghostly dip overnight, nearing the freezing mark in Central and Eastern Ontario.

With rain continuing into Monday, expect some of it to transform into wet snow by dawn. Early risers in Eastern Ontario, especially the Ottawa Valley, might find a sprinkling of this icy confetti. However, with temperatures close to freezing, this early snowfall might melt as quickly as a vampire in sunlight. But regions like Bancroft and Barry’s Bay might see a more noticeable 4-6cm of snow.

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As colder air follows this system, lake-effect snow will intensify, starting with Lake Superior on Monday. Snow squalls will push heavy snow into the Sault Ste. Marie region from Lake Superior. Other lake effect snow bands will impact areas east of Lake Superior, like Wawa and Marathon, though less intensely. This activity will persist until Tuesday afternoon.

Further south, Lake Huron and Georgian Bay will join the Halloween mischief by Monday evening. The main snow band could stretch from the Bruce Peninsula to between Barrie and Orillia, though its exact path remains uncertain.

By Monday's witching hour, Central Ontario's temperatures will dip below freezing, giving the lake effect snow a boost. Early Tuesday might even feature thundersnow, so don’t be too spooked if early Tuesday brings a rare thundersnow event!

On Halloween morning, you might have to brush off a light layer of snow from your jack-o'-lanterns. The sun should help melt some of it, but lake-effect snow might make a brief comeback just as the evening's ghoulish festivities begin. The Parry Sound region seems to be the favoured haunt for this snow activity. A clearer forecast for Tuesday evening and Wednesday will be conjured up closer to the event.

The projected snowfall accumulation may cause you to let out a blood-curdling scream in some areas. The Sault Ste. Marie area, in particular, could receive 15-25cm of snow, or possibly more if the snow remains intense. Areas east of Lake Superior might get around 6-12cm.

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Accumulation in Southern Ontario is uncertain due to temperatures near freezing. The Bruce Peninsula and Simcoe County might see 6-12cm, with localized areas possibly reaching 15-20cm if conditions are right.

Other parts of Southern Ontario might get a sprinkle of wet snow, but significant accumulation is unlikely. Deep Southwestern areas, like Sarnia, Windsor, and the Niagara region, probably won't see any snow in the coming days.

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Do You Want to Build a Snow Turkey? Parts of Ontario to See Up to 10-20cm of Snow for Thanksgiving

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October has started on a wild note in Ontario this year. After experiencing record-breaking temperatures soaring past 30°C earlier in the week, we're now shifting gears. The recent days have showcased more traditional fall weather with rain and chilly evenings. Yet, as the forecast suggests, it seems Mother Nature might be pulling a spooky Halloween prank on our region a bit early.

Indeed, the forecast hints at the season's first snowfall covering a vast portion of Northeastern Ontario and extending to the northern regions of Southern Ontario. By Tuesday, some areas could see snow accumulations reaching 10-20cm.

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As the temperatures gradually dip overnight heading into Sunday morning, anticipated rainfall is expected to transition into wet snow in areas such as Timmins, Cochrane, and Chapleau in Northeastern Ontario. The snow will slowly draw south, enveloping Sudbury, North Bay, and parts of Central Ontario. Considering the ground's retained warmth, most snowfall is likely to melt upon impact.

The snow is set to persist from Sunday night into Monday for Northeastern and Central Ontario. With temperatures possibly plummeting a few degrees below freezing in certain areas, we may start to see the snow accumulating on the ground by Monday morning.

During late Sunday and early Monday, the snow could be heavy at times, leading to slush-covered roads and diminished visibility. It's essential for drivers to be cautious, especially since many might not have transitioned to winter tires yet. Monday will continue the potential for scattered flurries, eventually turning into rain showers as temperatures climb. Although the snow might still be present in Northeastern Ontario by Monday night, it should dissipate by Tuesday morning.

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Predicting the exact accumulation is challenging. While models are good at estimating the amount of precipitation that will come from the sky, the ground's warmth and hovering freezing temperatures could result in much of the snow melting on contact.

Raw model data indicates that areas just north of Sudbury, like Timmins and Englehart, could experience the most snow. Here, upwards of 30cm might fall from the sky, but considering the factors mentioned earlier, the actual ground accumulation should end up between 10-20cm. These numbers are a rough idea and depend on various local dynamics.

The next few days carry the potential for both under and overperformance due to the expected amount of precipitation. Maximum accumulation is likely during Sunday night or early Monday. As Monday warms up, any snow gathered on the ground will quickly melt.

The rest of Northeastern Ontario away from the shoreline of Lake Superior and Georgian Bay including Sudbury, Elliot Lake, Chapleau and Cochrane can expect some minor accumulation ranging from 4 to 10cm by early Monday morning.

For Southern Ontario, Central Ontario might also experience the season's first few snowflakes, with accumulations possibly reaching 2-6cm in areas like Algonquin Park, Sundridge, and Huntsville. The rest of Central Ontario including Parry Sound, Bracebridge, Haliburton, Bancroft, Pembroke and Renfrew can expect a few flakes, but no substantial accumulation is anticipated.

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The imminent cold combined with the Great Lakes' warmth will bring the return of lake-effect precipitation in the coming days. Most of Southern Ontario will be spared from snow, but regions around Lake Huron and Georgian Bay could see rainfall totals of between 25-50mm by Monday's end, with some areas potentially receiving up to 75mm.

Elsewhere in Southern Ontario, intermittent showers are predicted, with the heaviest rainfall in Southwestern and Eastern Ontario. Regions in deep Southwestern Ontario and along the Golden Horseshoe might experience minimal rain, with less than 10mm of accumulation expected.

Another Week, Another Season; Accumulating Snow Returns to Parts of Southern Ontario for Monday and Tuesday

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Reality is setting in across Southern Ontario, reminding us that it isn't done with us just yet, despite the unseasonably warm weather we've enjoyed last week and into the weekend. We're in for a rollercoaster ride as temperatures drop from the 20s and even lower 30s a few days ago to daytime highs struggling to reach double digits in the coming days. The colder air will also bring back a sight we thought was behind us - snowflakes falling from the sky!

Indeed, we are looking at the risk of flurries and wet snow over the next couple of days across much of Southern Ontario. We've already seen some flakes in parts of Deep Southwestern Ontario early this afternoon. The potential for snow will encompass much of Southern Ontario by later tonight and into the overnight hours as temperatures drop to near the freezing mark. We aren't expecting significant accumulation, and with the ground still somewhat warm from last week's heat, much of what falls will likely melt on contact.

However, we do see the chance of minor accumulation east of Lake Huron and Georgian Bay, where lake effect snow could boost snow totals in those regions. Some higher elevations east of Lake Huron through parts of Huron, Bruce, Grey, and Perth counties could see up to 4-8cm of accumulation! Surrounding regions, including Central Ontario, may see a light dusting of snow, especially during the overnight hours when temperatures will be cold enough to allow for accumulation.

Scattered flurries will continue throughout the day on Tuesday, with the heaviest snow found east of Lake Huron and Georgian Bay. It appears Eastern Ontario will mostly escape the snow, as this will be mainly a lake-driven event. However, they could see a few flakes later in the day on Tuesday and Wednesday mornings as the moisture associated with this system moves out of the region.

Keep in mind, actual accumulation may vary due to temperatures being very close to the freezing mark. As such, totals may be lower than forecasted, given the potential for some snow to melt on contact with the ground. It will come down to how cold the temperature can get during the overnight hours, which will dictate how much snow will stick to the ground.

Be sure to take your time on the roads if you need to travel, as many have likely already switched from winter to summer tires. While this won't be a high-impact event, it could cause some delays since drivers haven't had to deal with wintry weather in a while. Stay safe!