First Isolated Severe Thunderstorm Risk of the Season for Parts of Southern Ontario Sunday Afternoon and Evening

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

It’s certainly been a while since we’ve had an isolated risk for severe thunderstorm activity in Southern Ontario, but here we are! Welcome to Spring! What we’re expecting is a line of thunderstorms and based on the time I’m writing this (11:11am), it looks like it has already begun to develop over Lake Erie. This line will continue to push to the northeast, affecting the Niagara Region and potentially all the way up to Barrie and parts of Simcoe County.

RADAR IMAGE FROM 11:12 AM EDT - MAP FROM INSTANTWEATHER PRO

Taking a look at the IW Pro app screenshot above, you can see the thunderstorm line beginning to develop over Lake Erie. We’re expecting nickel-size hail (perhaps a bit larger), strong wind gusts, torrential rain and frequent lightning with this line. Additionally, you can see a red outline of a Tornado Watch south of the border that covers areas south of Lake Erie.

An isolated tornado cannot be entirely ruled out with this system slipping past the international border and tracking into Ontario, so we’ll be keeping a very close eye on radar today. If you don’t already have our free app, InstantWeather, today may be a good day to download it so we can notify you of any rotating storms, funnel cloud reports or Environment Canada alerts.

Some models have also shown some very intense wind gusts, potentially exceeding 100km/h, especially in eastern Ontario, so we’re fairly concerned with that potential. Being an early season event, we decided to go with a Marginal (green) risk, but there certainly is a chance these storms could exceed the Slight (yellow) threshold, especially with the wind risk.

MAX WIND GUST FORECAST FROM THE HRRR MODEL - MAP FROM WEATHERBELL

In the image above, we see the HRRR model’s maximum wind gust forecast for Southern Ontario, showing some very strong winds in yellow and orange. This is just one model’s output so it’s not a guarantee. Nonetheless, if wind gusts do reach these levels, even in isolated areas, we could end up seeing some fairly strong wind damage to trees, hydro polls or perhaps even structures.

The main risk, timing wise, should begin this afternoon in the Niagara Region, with storms moving northeast from Lake Erie and that risk should continue to spread northeast into the evening hours. Generally, our main concern is for Niagara and areas north and east of Lake Ontario into eastern Ontario. However, we have highlighted parts of Southwestern Ontario, the GTHA, and Central Ontario as well, as we’ve seen some model data suggesting strong wind gusts are possible in those regions, along with hail, torrential rain, isolated flooding, frequent lightning and a small risk of an isolated tornado.

In general, the tornado risk is quite isolated. Having said that, with a potent system south of the border, there is always a chance we could see some tornado activity sneak into Ontario and based on some of the model data we’ve seen over the past couple of days, the risk of a spin-up or two cannot be ruled out.

We do plan on doing a livestream if storms continue to look strong this afternoon and evening so make sure to subscribe to our YouTube channel in order to get notified if and when we go live!

We’ll be posting more updates to our social media pages as well so if you’re on Facebook, you can find us at Ontario Storm Watch. We also have a fantastic storm reporting group on FB with Ontario Storm Reports. And if you’re on X/Twitter, you can find us at @IWeatherON.

More details ASAP and stay safe today, folks!

- Adam

Mid-March Snowfall Will Help Build Back Some Snowpack With 10-20cm Expected Across a Wide Stretch of Alberta & Saskatchewan

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

While we’re a little over a week away from the official start of spring, a majority of the snowpack is already gone across parts of Alberta and Saskatchewan. However, winter is still hanging on with more snow incoming over the next couple of days.

This will help to add some much-needed moisture to part of the region, especially since we have seen well below average snowfall since November. Unfortunately for Southern Alberta, the driest part of the Prairies, can expect little to none of this incoming moisture.

The snow will cross through the Rockies and into Alberta at around sunrise on Thursday and spread northeastward deeper into the province throughout the morning and into the afternoon. The snow will intensify starting in the early afternoon and this heavier snowfall will continue straight through overnight. This will lead to a large stretch of Central and Northern Alberta receiving 10-20cm of snow and up to 25cm possible to the north of Lake La Biche and Cold Lake through Friday morning.

Model Image showing the location and intensity of snow (Blue) and Rain (Green) at 4PM MT on Thursday

Light snow will make its way into Northern Saskatchewan early Thursday afternoon, followed by the more intense snowfall beginning in the early evening. This area of heavier snow will cross through Saskatchewan in an almost due easterly path and similar to in Alberta, it will dump 10-20cm across a large stretch of the province and up to 30cm from the Alberta border to almost La Ronge by Friday afternoon.

The arrival of additional moisture from a separate low-pressure system in the US on Friday morning makes the forecast in Central and Southern Saskatchewan a bit more complicated. This appears to be bringing a combination of rain, freezing rain, ice pellets, and snow to most of the southern half of the province throughout the morning as it merges with the system from the west.

There is still some uncertainty regarding the precipitation type and the area that could be impacted by the arrival of the secondary system. Therefore, for this forecast, we are only focusing on the snow coming from Alberta and we will cover this additional precipitation in a separate forecast that will be issued later in the day on Thursday

Model Image showing the location and intensity of snow (Blue), Rain (Green), Freezing rain (pink), and ice pellets (orange) at 2aM MT on Friday

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

Image of a total lunar eclipse/blood moon

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

What to Expect

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

Key Times for Ontario

Eastern Daylight Time

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

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

• Maximum Eclipse: 2:58 AM

• End of Totality: 3:31 AM

• End of Penumbral Eclipse: 6:00 AM

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

Viewing Tips

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

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

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

TOTAL CLOUD COVER ON FRIDAY MORNING - MAP FROM WEATHERBELL

Viewing Conditions Across Ontario

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

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

Photography Tips

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

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

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

More Freezing Rain & Snow in Store, Potential for Flash Freeze Across the Maritimes on Friday

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

The moisture-laden Colorado Low that has brought a mixed bag of precipitation to the Maritimes over the past two days appears to have one last trick up its sleeve. Cold air will flood into the region overnight, transitioning the rain over to snow and bringing some further complications.

In New Brunswick, the rain will start to switch over at around 1-2AM, however there will be a couple of hours of freezing rain in Central and Northern New Brunswick once again before the change over to snow. The heaviest snow is expected to fall in Carleton and Victoria Counties and northward into Madawaska and parts of Restigouche. This region can expect 10-20cm of snow by Saturday morning and the possibility of locally higher amounts, particularly in Madawaska County. Much of the rest of the province will see 5-10cm, with the exception of along the Fundy Coast and into the Southeast and Moncton area, where less than 5cm is anticipated.

Model Image showing the location and intensity of snow (Blue), Rain (Green), Freezing rain (Pink), and Ice pellets (Orange) at 5AM AT Friday

In Western Nova Scotia, the rain will taper off in the early morning hours of Friday, but it will be replaced by snow starting at around 8-9AM. The snow will be light and short-lived for much of the western half of the Mainland, but it will remain fairly steady in the Annapolis Valley through the afternoon and into the evening, leading to 5-10cm by the end of the day.

Across the rest of Mainland Nova Scotia, snowfall will be light and scattered as the band of snow makes its way across the province, leading to up to 5cm. The snow will eventually begin in Cape Breton late Friday evening, where it will continue through to Saturday morning. Most of the Island can expect 5-10cm, with lesser amounts around Sydney and up to 20cm in the Highlands.

The snow in Prince Edward Island, like in most of Nova Scotia, will also be very light and patchy. It will reach the province in the evening and the scattered flurries will continue into Saturday morning, leading to up to 5cm across the Island.

Modelled Temperatures at 9PM Thursday

Modelled Temperatures at 1PM Friday

The drop in temperatures that will cause the transition from rain to snow has another considerable implication. Temperatures are expected to plummet to several degrees below freezing across the region, after climbing into the double digits Thursday, and when combined with the preceding rain and melt-water, most of the Maritimes is under the threat of a flash freeze occurring on Friday.

This potential flash freeze could lead to wet, untreated surfaces quickly becoming icy and making travel hazardous as the temperatures drop across the region. Adding a layer of snow on top of this ice will keep things quite slippery as well.

The winds are expected to pick up on Friday, gusting up to 70km/h through most of the afternoon and then as high as 100km/h beginning in the evening and continuing for most of Saturday. These strong winds will likely reduce visibility due to blowing snow, both during and after the snow has stopped falling, and possibly lead to localized power outages.

Southern Ontario: School Bus Cancellations for Thursday, March 6, 2025

**Please refresh your page every few minutes to receive the latest update**

Cancellation & Closure Map (English Public and Catholic Schools)

Please note: School board boundaries are a rough estimate. Don’t use this map to determine what school board or weather zone you live in as accuracy isn’t guaranteed.

• Green = No Cancellations

• Red = Cancellations (Click for More Details)

• Purple = School Closures (Click for More Details)

List of Cancellations & Closures

English Public and Catholic Schools

• Avon MaitIand Public & Huron-Perth CathoIic: There are several cancellations and school closures, please visit this link for more details: https://geoquery.hpsts.ca/Alerts

• BIuewater Public & Bruce-Grey Catholic: There are several cancellations, please visit this link for more details: https://www.mybrucegreyschoolbus.ca/Cancellations.aspx

• Dufferin-PeeI Catholic: Buses to St Andrew, St Peter, St Benedict and RF Hall are cancelled today. St Andrew, St Peter and St Benedict are closed.

• Durham Public & Durham Catholic: DSTS has cancelled Zone 1, Zone 2 and Zone 3 transportation for today due to inclement weather.

• Near North Public & Nipissing-Parry Sound CathoIic: Bussing for all weather corridors are cancelled today.

• Kawartha Pine Ridge Public & Peterborough Victoria Northumberland Clarington Catholic: All busses are cancelled.

• PeeI Public: All transportation to RF Hall SS is cancelled today due to cancellations in Dufferin County.

• Rainbow Public & Sudbury Catholic: All busses are cancelled.

• Renfrew County Public & Renfrew County Catholic: Transportation services are CANCELLED for Zone 1 (Deep River), Zone 4 (Madawaska), Zone 5 (Cobden, Douglas, Eganville)

• Simcoe County Public & Simcoe Catholic: All busses are cancelled. Schools are closed in Muskoka.

• Thames Valley Public & London CathoIic: ALL school purpose vehicles servicing LDCSB & TVDSB in Middlesex County, Oxford County, Elgin County, and the Red Zone will be CANCELLED

• Tri-Board: Due to current road conditions and the expected drop in temperature, transportation is cancelled in the North Hastings weather zone today.

• Trillium LakeIands: All busses are cancelled and schools are closed.

• Upper Grand Public & Wellington CathoIic: Busses are cancelled for Centre Wellington, Town of Erin, Town of Rockwood (Division 2), North Wellington (Division 3), and Dufferin County and Robert F. Hall (Division 4). Schools in these Divisions are also closed.

French Schools

• Conseil catholique MonAvenir: Disruption to school transport and/or the opening of certain schools in the following regions: Durham, Simcoe, Peterborough

• Conseil scolaire catholique Providence: Busses are cancelled for Region of Oxford, Region of Middlesex (rural routes), Region of Bruce-Grey

• Conseil scolaire public du Grand Nord de l’Ontario (CSPGNO): All busses are cancelled

• Conseil scolaire Viamonde: Busses are cancelled for Region of Simcoe, Region of Durham, Region of Wellington

• Le Conseil scolaire public du Nord-Est de l’Ontario (CSPNE) & Conseil scolaire catholique Franco-Nord: All busses are cancelled.

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

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

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

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

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

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

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

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

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

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

---

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

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

Icy Mix, Flash Freeze and Strong Winds Could Bring Travel Disruptions to Ontario on Thursday

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

Thursday, March 6, 2025: Winter Weather Hazards For Parts of Ontario

Environment Canada is forecasting a mix of snow, strong winds, and rapidly dropping temperatures for Thursday. Rain will transition to snow across much of the province, with accumulations of 5 to 10 cm expected in several areas. Strong northwest winds could reach up to 80 km/h, leading to widespread blowing snow and dangerous travel conditions, especially southeast of Lake Huron and Georgian Bay. Additionally, a sharp temperature drop will cause any standing water or wet surfaces to freeze quickly, creating hazardous icy conditions. Eastern Ontario and the Greater Golden Horseshoe will see a heightened risk of ice as rain transitions to freezing conditions throughout the day. Travelers should prepare for difficult driving conditions, reduced visibility, and potential road closures. Stay updated on this evolving system as details continue to develop.

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

Location: Portions of central Ontario and southern portions of northeastern Ontario

• Hazard(s): Snow, Blowing Snow, and Ice

• Timing: Thursday

• Impact(s): Difficult travel conditions, reduced visibility, and possible road closures.

• Confidence: High

• Impact Level: Moderate

Rain will transition to snow early Thursday morning, with snowfall accumulations of 5 to 10 cm expected. Alongside this snowfall, gusty northwest winds will lead to blowing snow in exposed areas. A sharp temperature drop will cause any standing water or wet surfaces to freeze quickly, creating hazardous icy conditions Thursday morning.

Location: Areas southeast of Lake Huron and Georgian Bay

• Hazard(s): Snow, Blowing Snow, Wind, and Ice

• Timing: Thursday

• Impact(s): Difficult travel conditions, reduced visibility, possible road closures, and potential power outages.

• Confidence: Moderate

• Impact Level: High

Rain will transition to snow overnight or early Thursday morning, with 5 to 10 cm of accumulation possible. Strong northwest winds up to 80 km/h are expected, causing widespread blowing snow and dangerous whiteout conditions. The sharp temperature drop will also lead to ice formation as wet surfaces quickly freeze Thursday morning.

Location: Portions of eastern Ontario and the Greater Golden Horseshoe

• Hazard(s): Ice

• Timing: Thursday

• Impact(s): Difficult travel conditions due to rapid freezing and ice buildup.

• Confidence: Moderate

• Impact Level: Moderate
  
  Rain will transition to snow Thursday morning or afternoon, accompanied by a sharp drop in temperature. Any standing water or wet surfaces are expected to freeze quickly throughout the day, leading to slick and icy conditions on roads and sidewalks.
  

Location: Portions of southwestern Ontario and areas northeast of Lake Erie and Lake Ontario

• Hazard(s): Snow, blowing snow, wind, and ice

• Timing: Thursday

• Impact(s): Difficult travel conditions, reduced visibility, and possible road closures. Possible power outages.

• Confidence: Moderate

• Impact Level: Moderate

Rain will transition to snow overnight or early Thursday morning, with snowfall accumulations of 2 to 4 cm expected. Strong west or southwest winds, potentially reaching 80 km/h, may cause blowing snow in exposed areas, further reducing visibility. A sharp temperature drop will also lead to icy conditions as standing water or wet surfaces freeze rapidly Thursday morning. Travelers should prepare for hazardous road conditions and potential disruptions.

---

Friday, March 7, 2025: Snow Squalls & Blowing Snow

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

Location: Southeast of Lake Superior, Lake Huron, and Georgian Bay

• Hazard(s): Snow and blowing snow

• Timing: Beginning Thursday evening and continuing through Friday

• Impact(s): Possible difficult travel conditions

• Confidence: Moderate

• Impact: Moderate

Lake effect snow is expected to develop Thursday night and persist through Friday, bringing total snowfall amounts of 5 to 10 cm. Gusty winds may lead to areas of blowing snow, particularly in exposed locations, reducing visibility and making travel hazardous. Drivers should prepare for changing road conditions and potential delays.

---

Final Thoughts:

As this storm system moves through, travel across parts of Ontario will become increasingly difficult on Thursday due to a combination of snow, blowing snow, strong winds, and icy conditions. The transition from rain to snow, along with a sharp temperature drop, will create hazardous roads as wet surfaces quickly freeze. Power outages are also a concern in areas experiencing stronger winds, particularly near Lake Erie and Lake Ontario.

Lake effect snow will add to the challenges on Friday, especially southeast of Lake Superior, Lake Huron, and Georgian Bay, where accumulating snowfall and blowing snow could lead to reduced visibility and treacherous driving conditions. While uncertainty remains regarding exact snowfall totals, the potential for rapid changes in weather conditions warrants extra caution.

If you must travel, plan ahead, check road conditions frequently, and be prepared for sudden deteriorations. Stay tuned for updates as this system develops.

Be safe, folks!

---

Disclaimer: These forecasts are issued by Environment Canada and typically published via their Twitter/X accounts. We receive these forecast via a daily email and often publish them for our communities to see.

Southern Ontario: School Bus Cancellations for Wednesday, March 5, 2025

**Please refresh your page every few minutes to receive the latest update**

Cancellation & Closure Map (English Public and Catholic Schools)

Please note: School board boundaries are a rough estimate. Don’t use this map to determine what school board or weather zone you live in as accuracy isn’t guaranteed.

• Green = No Cancellations

• Red = Cancellations (Click for More Details)

• Purple = School Closures (Click for More Details)

List of Cancellations & Closures

English Public and Catholic Schools

• Durham Public & Durham Catholic: DSTS has cancelled Zone 1, Zone 2 and Zone 3 transportation for today due to inclement weather.

• Near North Public & Nipissing-Parry Sound CathoIic: Bussing for all weather corridors are cancelled today.

• Rainbow Public & Sudbury Catholic: All busses are cancelled.

• Renfrew County Public & Renfrew County Catholic: Transportation services are CANCELLED for ALL AREAS by for Wednesday March 5, 2025 due on going Freezing Rain with mixed precipitation forecasted throughout the day.

• Simcoe County Public & Simcoe Catholic: Busses are cancelled for Muskoka.

• Tri-Board: Due to current road conditions, transportation is cancelled in some of Tri-Board’s north and central weather zones today. For a complete list of bus cancellations and delays visit: https://triboard.mybusplanner.ca/Alerts

• Trillium LakeIands: All school vehicles to schools in all Zones for Trillium Lakelands District School Board have been cancelled.

French Schools

• Conseil des écoles publiques de l’Est de l’Ontario (CEPEO): School transport is cancelled today for schools in Pembroke due to poor road conditions in this area.

• Conseil des écoles catholiques de langue française du Centre-Est: transportation has been cancelled for schools in Pembroke due bad road conditions.

• Conseil scolaire public du Grand Nord de l’Ontario (CSPGNO): All busses are cancelled.

• Le Conseil scolaire public du Nord-Est de l’Ontario (CSPNE) & Conseil scolaire catholique Franco-Nord: All busses are cancelled.

Threat of Localized Flooding & Freezing Rain Risk in New Brunswick with the Arrival of a Winter Storm Wednesday

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

A Colorado Low is set to move through the Maritimes this week, bringing a mixture of rain, freezing rain, and snow to the region, along with the risk of flooding as temperatures rise.

Brief light snow will begin in Southwestern New Brunswick at around sunrise on Wednesday, spreading northeastward into the province throughout the morning and early afternoon. There is a chance for some freezing drizzle around Saint John mixed with the snow. Meanwhile in Nova Scotia, the precipitation will fall as rain across much of the western half of the province, aside from some light snow expected in Northern Nova Scotia.

Model Image showing the location and intensity of snow (Blue), Rain (Green), Freezing rain (Pink), and Ice pellets (Orange) at 1PM AT Wednesday

By the mid-afternoon, the bulk of the moisture from the system will push eastward into the region, bringing rain to Nova Scotia and Southern New Brunswick while Central and Northern New Brunswick will start to receive snow. The precipitation will reach PEI later in the afternoon as a mix of rain and snow across the Island.

Model Image showing the location and intensity of snow (Blue), Rain (Green), Freezing rain (Pink), and Ice pellets (Orange) at 12AM AT Thursday

Starting in the evening, the warm air and rain will start to push northward, leading to a transition from snow to a few hours of freezing rain across Central and Northern New Brunswick, as well as into PEI and Cape Breton. The freezing rain will continue overnight and into early Thursday morning. Ice accretions of up to 5mm are likely, but buildup will be short-lived as the temperatures will continue to rise and the freezing rain will switch over to rain for the remainder of Thursday.

Ahead of the transition to freezing rain and rain, up to 10cm of snow will fall, with the highest amounts expected in Retigouche County and into the Acadian Peninsula.

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

Not only will the fresh snowfall melt with the rain and temperatures climbing into the double digits on Thursday, but a considerable amount of pre-existing snowpack, especially across New Brunswick will also melt. Parts of Central and Northern New Brunswick have over 70cm of snow on the ground as of Tuesday evening and that value is expected to drop to below 50cm in some areas by Friday. Similarly, Moncton and Saint John, where 10-20cm is already on the ground, could see most, if not all, of their snow melt.

This rapid melting of the snow, along with some heavy rain expected later in the day on Thursday, has led to a significant flooding threat across New Brunswick. The ground is still frozen and recent frigid temperatures have led to ice buildup on lakes and rivers, which will limit where the water from the snow melt and rain can go.

The situation in Nova Scotia and into PEI is less widespread with lesser snowpack overall. There are some areas in Nova Scotia that have up to 30cm of snow on the ground that will almost completely melt, namely in the Annapolis Valley and in Cumberland and Colchester Counties. Those in Cape Breton can expect to see some of their snowpack melt, but the Highlands will experience very little change. In Prince Edward Island, on the other hand, next to no snow will remain on the Island come Friday aside from pockets of up to 5cm possibly remaining in Prince and/or Kings Counties.

The modelled depth of snow across Atlantic Canada, in centimetres, as of 8pm Tuesday.

Flooding Risk & Heavy Snow Possible Wednesday For Parts of Ontario Says Environment Canada's Forecast

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

A Colorado Low is expected to bring a mix of rain and snow to Ontario on Wednesday, potentially leading to flooding concerns in some areas and hazardous winter weather in others. The exact track of this system remains uncertain, and future updates may bring changes to precipitation amounts and affected areas. Here’s what Environment Canada has mentioned in their forecast:

---

Southern Ontario: Flooding Risk for Tuesday night - Wednesday, March 5:

Hazard: Rain
Location: East of Lake Huron, central Ontario, and portions of northeastern Ontario
Timing: Tuesday night through Wednesday
Impact: Potential flooding in low-lying areas and possible washouts near rivers, creeks, and culverts.
Confidence: Low
Impact: High

A strong system moving into the province could bring significant rainfall to these regions. The combination of heavy rain and rapid snowmelt in areas with a deep snowpack could lead to localized flooding issues. The exact track of the system remains uncertain, so be sure to stay updated as new information becomes available.

Hazard: Rain
Location: Southwestern, eastern Ontario, and the Golden Horseshoe
Timing: Tuesday night through Wednesday
Impact: Possible flooding in low-lying areas.
Confidence: Low
Impact: Moderate

Rainfall from the same system could cause flooding concerns in urban areas and places with poor drainage. While the overall flood risk is lower than in central and northeastern Ontario, localized issues remain possible due to snowmelt and prolonged rainfall.

---

Northeastern Ontario: Heavy Snow Possible Wednesday, March 5:

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

Environment Canada’s forecast:

Hazard: Snow
Location: Northeastern Ontario and areas north of Lake Superior
Timing: Wednesday
Impact: Difficult travel conditions, reduced visibility, and possible road closures.
Confidence: Low
Impact: High

While some areas receive heavy rain, northern Ontario will likely see significant snowfall, which could lead to hazardous travel conditions. The heaviest snow is expected in areas north of Lake Superior, but the exact placement of the heaviest bands will depend on the storm’s final track.

---

Final Thoughts:

There remains significant uncertainty regarding the exact storm track, precipitation types, and total amounts. Future updates may adjust the areas of concern and the severity of the impacts. Residents in flood-prone areas should monitor conditions closely and be prepared for potential flooding. Those in Northeastern Ontario should prepare for heavy snowfall and difficult travel conditions. Stay tuned for further updates as more details become available.

---

Disclaimer: These forecasts are issued by Environment Canada and typically published via their Twitter/X accounts. We receive these forecast via a daily email and often publish them for our communities to see.

Southern Ontario: School Bus Cancellations for Friday, February 28, 2025

**Please refresh your page every few minutes to receive the latest update**

Cancellation & Closure Map (English Public and Catholic Schools)

Please note: School board boundaries are a rough estimate. Don’t use this map to determine what school board or weather zone you live in as accuracy isn’t guaranteed.

• Green = No Cancellations

• Red = Cancellations (Click for More Details)

• Purple = School Closures (Click for More Details)

List of Cancellations & Closures

English Public and Catholic Schools

• Kawartha Pine Ridge Public & Peterborough Victoria Northumberland Clarington Catholic: All busses are cancelled.

• Near North Public & Nipissing-Parry Sound CathoIic: All busses are cancelled.

• Rainbow Public & Sudbury Catholic: All busses are cancelled.

• Tri-Board: Transportation is cancelled in the North Hastings weather zone today.

French Schools

• Conseil catholique MonAvenir: Busses are cancelled in the Peterborough Region

• Conseil scolaire public du Grand Nord de l’Ontario (CSPGNO): All busses are cancelled.

• Le Conseil scolaire public du Nord-Est de l’Ontario (CSPNE) & Conseil scolaire catholique Franco-Nord: All busses are cancelled.

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

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

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

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

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

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

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

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

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

Likely (75–90% Chance)

• Near North District School Board (All Regions)

• Tri-Board (North Hastings)

Possible (50–75% Chance)

• Bluewater District School Board (Bruce Peninsula)

• Simcoe County District School Board (North Zone)

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

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

• Renfrew County District School Board (Madawaska)

• Rainbow District School Board

• Algoma District School Board

Maybe (25–50% Chance)

• Bluewater District School Board (Rest of Regions)

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

• Trillium Lakelands District School Board (South CKL)

• Kawartha Pine Ridge District School Board (Peterborough)

• Tri-Board (North & Central Frontenac)

• Renfrew County District School Board (Rest of Regions)

• Upper Canada District School Board

Unlikely (10–25% Chance)

• STWDSTS (Dufferin & Wellington)

• Simcoe County District School Board (South Zone)

• Durham District School Board (North)

• Kawartha Pine Ridge District School Board (Northumberland)

• Tri-Board (Rest of Regions)

• Ottawa-Carleton District School Board

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

---

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

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

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

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

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

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

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

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

PRECIPITATION TYPE - MAP FROM WEATHERBELL

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

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

PRECIPITATION TYPE - MAP FROM WEATHERBELL

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

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

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

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

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

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

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

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

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

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

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

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

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

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

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

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

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

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

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

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

Quick Blast of Intense Snowfall Could Bring Over 20cm to Parts of Saskatchewan and Manitoba

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

February has been a quiet month across the Prairies, as far as active weather is concerned. That has changed though, with the arrival of warmer air in the past few days, which has also brought heavier snowfall back to the region. Now, we are looking at that heavy snow across Saskatchewan and Manitoba for Thursday and Friday.

The snow will begin early Thursday in Northern Saskatchewan and surge southeastward throughout most of the morning, crossing into Manitoba at around 8-9am. The snow will be steady and fairly light for most of the day, falling at up to 2cm/hr, leading to a large swath of over 10cm across both provinces.

In the late afternoon and early evening, the snow will begin to taper off in Saskatchewan while at the same time, intensifying in Central Manitoba. The heavier snow is expected to cross the province throughout the evening and will bring snowfall totals to the higher end of the 10-20cm range, with a strong likelihood of localized pockets of over 20cm, particularly around Flin Flon, The Pas and Norway House. The intensified snowfall will also be associated with some stronger wind gusts of up to 70km/h, which could result in isolated whiteouts due to blowing snow.

As the short-lived system exits the region, the snow will finally taper off in Saskatchewan shortly after midnight on Friday and in Manitoba just before sunrise. The winds are also expected to weaken Friday morning, therefore reducing the blowing snow risk.

Southern Ontario: School Bus Cancellations for Wednesday, February 19, 2025

**Please refresh your page every few minutes to receive the latest update**

Cancellation & Closure Map (English Public and Catholic Schools)

Please note: School board boundaries are a rough estimate. Don’t use this map to determine what school board or weather zone you live in as accuracy isn’t guaranteed.

• Green = No Cancellations

• Red = Cancellations (Click for More Details)

• Purple = School Closures (Click for More Details)

List of Cancellations & Closures

English Public and Catholic Schools

• Avon MaitIand Public & Huron-Perth CathoIic: There are several cancellations and school closures, please visit this link for more details: https://geoquery.hpsts.ca/Alerts

• BIuewater Public & Bruce-Grey Catholic: There are multiple cancellations and school closures, please visit this link for more details: https://www.mybrucegreyschoolbus.ca/Cancellations.aspx

• Dufferin-PeeI Catholic: Buses to St Andrew, St Peter, St Benedict & RF Hall are cancelled today.

• PeeI Public: All transportation to RF Hall SS is cancelled today due to cancellations in Dufferin County.

• Thames Valley Public & London CathoIic: There are isolated cancellations, please visit this link for more details: https://transportation.mybigyellowbus.ca/Cancellations.aspx

• Upper Grand Public & Wellington CathoIic: Busses are cancelled for North Wellington (Division 3) & Dufferin County and RF Hall (Division 4).

French Schools

• Conseil scolaire catholique Providence: Busses are cancelled for the Region of Bruce-Grey & Huron Perth of Middlesex Region

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

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

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

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

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

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

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

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

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

Almost Certain (90–99% Chance)

• Avon Maitland District School Board (Goderich)

• Bluewater District School Board (All Regions)

• Simcoe County District School Board (West Zone)

Likely (75–90% Chance)

• Avon Maitland District School Board (Listowel)

• STWDSTS (Dufferin)

• Simcoe County District School Board (Central Zone)

Possible (50–75% Chance)

• Avon Maitland District School Board (Exeter & Stratford)

• STWDSTS (Wellington)

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

Maybe (25–50% Chance)

• Durham District School Board (North)

• Trillium Lakelands District School Board (South CKL)

Unlikely (10–25% Chance)

• Thames Valley District School Board (Middlesex & Oxford)

• Waterloo Region District School Board

• Peel District School Board (North)

• Trillium Lakelands District School Board (North CKL)

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

---

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

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

Southern Ontario: School Bus Cancellations for Tuesday, February 18, 2025

**Please refresh your page every few minutes to receive the latest update**

Cancellation & Closure Map (English Public and Catholic Schools)

Please note: School board boundaries are a rough estimate. Don’t use this map to determine what school board or weather zone you live in as accuracy isn’t guaranteed.

• Green = No Cancellations

• Red = Cancellations (Click for More Details)

• Purple = School Closures (Click for More Details)

List of Cancellations & Closures

English Public and Catholic Schools

• Avon MaitIand Public & Huron-Perth CathoIic: There are several cancellations and school closures, please visit this link for more details: https://geoquery.hpsts.ca/Alerts

• BIuewater Public & Bruce-Grey Catholic: There are multiple cancellations and school closures, please visit this link for more details: https://www.mybrucegreyschoolbus.ca/Cancellations.aspx

• Dufferin-PeeI Catholic: Buses to St Andrew, St Peter, St Benedict & RF Hall are cancelled today. St Andrew, St Peter and St Benedict are CLOSED,

• Durham Public & Durham Catholic: DSTS has cancelled Zone 1 transportation for today

• Kawartha Pine Ridge Public & Peterborough Victoria Northumberland Clarington Catholic: All transportation is cancelled today in Northumberland, Clarington, Peterborough City and County.

• PeeI Public: All transportation to RF Hall SS is cancelled today due to cancellations in Dufferin County.

• Simcoe County Public & Simcoe Catholic: Busses are cancelled in all Simcoe County zones.

• Thames Valley Public & London CathoIic: School purpose vehicles are CANCELLED for the day in MIDDLESEX & OXFORD Counties.

• Trillium Lakelands: All school vehicles to schools in Zone 4 and Zone 5 have been cancelled today.

• Upper Grand Public & Wellington CathoIic: All busses are cancelled and schools are closed, except for RF Hall.
  

French Schools

• Conseil catholique MonAvenir: Disruption to school transport and/or the opening of certain schools in the following regions: Wellington, Simcoe & Peterborough

• Conseil scolaire catholique Providence: Busses are cancelled in Region of Oxford, Region of Middlesex, Region of Bruce-Grey

• Conseil scolaire Viamonde: Busses are cancelled for the Region of Durham and the Region of Waterloo (Guelph routes)

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

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

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

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

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

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

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

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

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

Almost Certain (90–99% Chance)

• Bluewater District School Board (All Regions)

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

Likely (75–90% Chance)

• Avon Maitland District School Board (Goderich)

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

Possible (50–75% Chance)

• Avon Maitland District School Board (Listowel)

• STWDSTS (Dufferin)

Maybe (25–50% Chance)

• Avon Maitland District School Board (Exeter & Stratford)

• STWDSTS (Wellington)

• Durham District School Board (North)

• Trillium Lakelands District School Board (South CKL)

Unlikely (10–25% Chance)

• Waterloo Region District School Board

• STWDSTS (Guelph)

• Peel District School Board (North)

• York Region District School Board

• Kawartha Pine Ridge District School Board (Clarington)

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

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

---

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

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

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

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

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

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

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

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

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

Projected Snowfall Totals:

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

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

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

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

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

Stay safe and stay warm!

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

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

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

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

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

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

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

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

PRECIPITATION TYPE - MAP FROM WEATHERBELL

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

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

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

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

PRECIPITATION TYPE - MAP FROM WEATHERBELL

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

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

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

PRECIPITATION TYPE - MAP FROM WEATHERBELL

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

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

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

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

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

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

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

HOURLY SNOWFALL RATE/intensity - MAP FROM WEATHERBELL

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

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

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

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

ESTIMATED WIND GUSTS - MAP FROM WEATHERBELL

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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