August 12, 2026

Potential Tornado Risk for Greater Toronto Area and Southwestern Ontario With Severe Storms Wednesday

August 12, 2026/ Brennen Perry

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

Another storm threat is on the horizon for Southern Ontario this week, with widespread severe weather potential expected across a large portion of Southwestern Ontario and into the Golden Horseshoe on Wednesday.

A cluster of thunderstorms is expected to develop during the early afternoon to the northwest of the Greater Toronto Area before gradually tracking southeastward through the afternoon.

These storms will have the potential to produce all severe hazards, including damaging wind gusts, up to Timbit-sized hail, and an isolated tornado. Some stronger cells could even produce locally up to golf ball-sized hail, particularly closer to the Lake Ontario shoreline.

Join Us on YouTube for Storm Coverage:

We'll be providing comprehensive live coverage of any storms that develop on Wednesday on our YouTube channel. Our team will be tracking storms in real time with live radar analysis, warnings, and storm reports, so if severe weather threatens your area, be sure to join us live to help stay informed.

Flooding will also be a concern, as there are some indications that these storms could be fairly slow-moving and potentially regenerate over the same areas for several hours.

This will be especially important to watch in urban areas such as the Greater Toronto Area, as well as the Niagara Region, which has already been hit hard by flooding over the past few weeks. Any locations that receive repeated thunderstorms could quickly pick up significant rainfall over a short period of time.

As for the tornado risk, the latest data has been particularly focused on the western GTA through Hamilton and into portions of the Niagara Region during the mid to late afternoon hours.

The tornado threat isn't particularly strong, but the consistency in the latest data is noteworthy. We can't rule out a brief tornado somewhere around the Lake Ontario shoreline as storms move through the region.

A tornado risk may also extend farther west into Southwestern Ontario, including around Kitchener and London. However, this threat is less certain because storm development becomes more questionable farther west.

We could also see some isolated thunderstorms develop across Central Ontario and track into portions of the Ottawa Valley.

The severe threat doesn't appear to be as widespread in this region compared to Southwestern Ontario and the Golden Horseshoe. However, a few stronger storms capable of producing large hail and damaging wind gusts will still be possible.

Most of the thunderstorm activity is expected to gradually wind down during the early evening as we lose the daytime heating that will help fuel these storms.

One factor that could throw a wrench into Wednesday's severe weather setup is wildfire smoke.

As we've seen with a few previous storm threats, including on Monday when smoke contributed to part of the severe risk busting across Southwestern Ontario, wildfire smoke can have a significant impact on how much instability is able to build.

Models show some fairly thick upper-level wildfire smoke covering much of Southwestern Ontario and the Golden Horseshoe on Wednesday morning.

However, the latest data suggests that the smoke should begin to thin somewhat around or shortly after the noon hour. If that happens as expected, there should still be enough daytime heating to allow the atmosphere to destabilize and thunderstorms to develop.

If the smoke hangs around longer or is thicker than expected, storms could struggle to develop and take advantage of the otherwise favourable environment.

At this point, that bust potential appears fairly low, but it can't be completely taken off the table.

Based on the latest model data, there appear to be two main corridors where thunderstorm development could begin sometime between approximately 12 and 2 PM across Southern Ontario.

The first area is around the southern Georgian Bay shoreline, extending southeastward into the Lake Simcoe region.

Isolated thunderstorms are expected to develop in this area before quickly strengthening as they slowly track southeastward toward Lake Ontario and the Greater Toronto Area.

Given the environment in place, any storm that can remain isolated could quickly become severe, with large hail and damaging wind gusts being the main threats initially.

The second area of potential development extends from Algonquin Park into the Ottawa Valley, where a few isolated thunderstorms may begin to pop up during the early afternoon.

It remains unclear whether these storms will become organized enough to produce widespread severe weather. However, locally large hail and damaging wind gusts can't be ruled out with any stronger cells that develop.

By the middle of the afternoon, another area could enter the picture around the southeastern Lake Huron shoreline as isolated thunderstorms potentially begin to develop.

Storm development in this area is more questionable, and not every model shows storms forming. However, any thunderstorms that do develop will have a favourable environment to work with around Sarnia, London and Goderich.

These storms could produce up to toonie-sized hail along with damaging wind gusts. An isolated tornado risk also can't be ruled out, particularly if storms are able to remain discrete as they mature and move inland from the Lake Huron shoreline.

The most notable tornado threat appears to develop as the earlier storms track into the Greater Toronto Area sometime between approximately 3 and 5 PM. The storms are then expected to continue southeastward into Hamilton and the Niagara Region between approximately 4 and 6 PM.

Models have been fairly consistent in highlighting this corridor as having the strongest tornado potential on Wednesday. However, one factor that could reduce the tornado threat is storm mode.

Some models show the individual thunderstorms gradually merging into a larger cluster as they move into the Golden Horseshoe. If this happens, a more linear storm structure would likely reduce the tornado and very large hail threat, while increasing the focus on damaging wind gusts and heavy rainfall.

If the storms can remain more isolated, there is a chance we could see a few supercells move through portions of the Golden Horseshoe.

Those stronger storms could produce Timbit to golf ball-sized hail, damaging wind gusts and an isolated tornado.

Farther east, isolated thunderstorms may continue to affect the Ottawa Valley through the late afternoon.

While the severe threat is more isolated compared to the Golden Horseshoe, some stronger cells could still produce locally large hail, damaging wind gusts and torrential rainfall.

This activity should gradually weaken shortly after the dinner hour as instability begins to decrease.

Across Southwestern Ontario and the Greater Toronto Area, thunderstorms are expected to slowly track southeastward toward Lake Erie and Lake Ontario through the late afternoon and early evening.

Storms should then gradually weaken as they move south of the border and daylight begins to fade.

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

For now, our maximum severe threat for Wednesday is a widespread (level 2/5) risk covering a large portion of Southwestern Ontario and the Golden Horseshoe.

There is a chance we may introduce a strong (level 3/5) risk around parts of the Golden Horseshoe if Wednesday morning's data continues to strengthen the signal for large hail, damaging wind gusts and an isolated tornado.

The widespread risk currently includes Toronto, Mississauga, Hamilton, Niagara Falls, Brantford, Tillsonburg, Woodstock, London, St. Thomas, Sarnia, Grand Bend, Goderich, Kitchener, Guelph, Orangeville, Hanover, Collingwood, Barrie, Orillia, Newmarket and Oshawa.

Storms within this region will have the potential to produce damaging wind gusts in excess of 100 km/h, large hail up to Timbit-sized, and an isolated tornado.

Locally larger hail approaching golf ball size could be possible with the strongest storms, particularly around the Lake Ontario shoreline if storms are able to remain isolated.

The rest of Southern Ontario, including Deep Southwestern Ontario and portions of Central and Eastern Ontario, is under an isolated severe risk for Wednesday.

Storms in these areas could produce marginally severe hazards, including up to quarter-sized hail, locally approaching toonie size, isolated damaging wind gusts in excess of 90 km/h and heavy rainfall.

As always with summertime thunderstorm risks, not everyone will see severe weather. However, those who do get caught under one of the stronger storms could experience significant conditions over a short period of time.

We'll be closely monitoring the latest data and any changes caused by wildfire smoke Wednesday morning, as even a small change in available instability could have a major impact on where storms develop and how strong they become.

August 10, 2026

Strong Severe Thunderstorms Target Calgary and Surrounding Area Today with the Risk of Possibly Destructive Wind-Driven Hail

August 10, 2026/ Alannah Campbell

Yesterday afternoon, we shared the Environment Canada thunderstorm outlook for today, which had a High Risk for severe weather today for parts of Central and Southern Alberta, including Calgary. That risk did not diminished overnight and we are still expecting to see some strong thunderstorms today.

We're already seeing some non-severe thunderstorms in parts of Central Alberta this morning. These storms should stay sub severe over the next few hours, but there is a slight chance that one could surpass the threshold of becoming severe.

More thunderstorms are expected to develop this afternoon, popping up across much of the province, some of which may persist into the overnight hours. As far as the Calgary area is concerned, it's likely that severe storms will develop to the northwest of the city in the mid-to-late afternoon, around 3-5pm, which could long-lived and track southeast towards the Saskatchewan border through to the late evening.

***Simulated reflectivity from the hrrr model at 5pm MdT, courtesy of weatherbell.***

At this point, there is still a bit of disagreement between models when it comes to what kind of thunderstorms could develop today and it's most likely that we will see a mixture of individual supercells in the south and multicellular clusters of thunderstorms in Central Alberta.

The multicellular clusters of storms are expected to mostly have a strong wind risk, along with the possibility of some fairly large hail. Meanwhile, the supercell storms will come with the greatest threat of large hail, which could be bigger than golf balls, as well as damaging winds well above 100km/h. This could particularly be the case for the storms that form to the northwest of Calgary and track into Southern Alberta.

As with any severe thunderstorms in the Prairies, especially with supercells, there will a tornado risk today, however it's looking like the greatest threat today will be large hail and damaging straight-line winds.

Today's setup is actually looking a little reminiscent of the destructive hail storm that tracked through parts of Calgary in August 2024, with the possibility of large hail that could be driven by very strong winds hitting the city. If you live in the area outlined in orange on our forecast map, especially if you're in Calgary, you may want to take precautions in the event that a similar destructive hail storm does end up forming.

We will certainly be going live today and we will be covering the severe thunderstorm and tornado risk in Southern Ontario, as well. Please be sure to join us later at instantweather.ca/live!

August 09, 2026

Ottawa Valley and Central Ontario Face Tornado and Large Hail Risk Monday as Wildfire Smoke Adds Uncertainty to Storm Threat for Southwestern Ontario

August 09, 2026/ Brennen Perry

After at least two tornadoes were confirmed to have touched down in Southern Ontario on Saturday, the risk of active weather will continue into the start of the week.

A complex, multi-wave severe weather threat is expected to unfold across Southern Ontario on Monday, including in some of the areas that experienced the worst storms on Saturday.

The first round will begin with a complex of storms moving across Michigan and potentially crossing the border into Deep Southwestern Ontario around sunrise.

There is some uncertainty about how strong these storms will be since there will not be any daytime heating to fuel them. However, the environment could still be supportive enough for the storms to reach near-severe or severe levels.

Join Us on YouTube for Storm Coverage:

We'll be providing comprehensive live coverage of any storms that develop Monday on our YouTube channel. Our team will be tracking storms in real time with live radar analysis, warnings, and storm reports, so if severe weather threatens your area, be sure to join us live to help stay informed.

The strongest severe weather threat could take shape during the early afternoon as isolated cells begin to develop across Central Ontario and track into the Ottawa Valley.

Another corridor of storms may develop around Lake Simcoe before tracking through the Kawartha Lakes and into the Peterborough and Belleville areas.

These storms could produce all severe weather hazards, including hail up to the size of Timbits, with locally larger hail approaching golf ball size. Damaging wind gusts and an isolated tornado will also be possible.

Another round of storms could develop during the late afternoon and early evening across Deep Southwestern Ontario and into the Niagara Region.

However, wildfire smoke from Western Canada is expected to move into Southwestern Ontario during the late afternoon.

The smoke should remain elevated high in the atmosphere, so impacts at ground level are expected to be limited. However, as we have seen in the past, elevated wildfire smoke can reduce daytime heating and inhibit thunderstorm development.

A strong complex of storms is expected to move across Lower Michigan during the pre-dawn hours on Monday.

Based on the latest data, these storms could reach the Canadian border sometime between 6 and 8 a.m.

There is still some uncertainty about how strong the storms will be by the time they track into Deep Southwestern Ontario.

However, the environment could support damaging wind gusts, particularly around Essex County. Isolated large hail up to the size of toonies will also be possible.

By the early afternoon, attention will turn to two main corridors where thunderstorm development appears most likely.

The most prolific storms are expected to form around Algonquin Park before tracking through Pembroke, Renfrew and into the Ottawa region.

These storms could produce large hail, damaging wind gusts and an isolated tornado.

Another area where isolated storms may develop includes the Lindsay area, where one of Saturday’s confirmed tornadoes occurred.

Storms are once again expected to form around Lake Simcoe before slowly tracking through the Kawartha Lakes, Peterborough and Belleville corridor.

Large hail will likely be the primary threat in this area, but damaging wind gusts and an isolated tornado cannot be ruled out.

However, a familiar theme this year could throw a wrench into yet another severe weather threat, and that is wildfire smoke.

This time, the smoke will originate from the West Coast. It is expected to remain mostly elevated in the upper levels of the atmosphere, meaning significant impacts on air quality are not anticipated.

What the smoke can do, however, is act like a blanket over the region. This could reduce daytime heating and make it more difficult for thunderstorms to develop.

Based on the latest data, the smoke should be less of an issue across the Central Ontario and Ottawa Valley corridor.

This means those areas are less likely to experience a smoke-driven bust, although that possibility cannot be completely ruled out.

Thicker smoke across Southwestern Ontario could have a greater impact on thunderstorm development, despite the presence of an otherwise fairly strong severe weather environment.

The significant tornado parameter provides an overview of where the atmospheric environment could support tornadoes if a storm develops in a particular area.

Current data shows a somewhat favourable environment across Deep Southwestern Ontario, extending into portions of the western Greater Toronto Area and the Niagara Region during the late afternoon and early evening.

However, as mentioned above, thunderstorm development in this area remains highly uncertain because of the expected presence of wildfire smoke.

For now, we are maintaining a widespread severe risk as the highest threat level in this forecast.

We may consider upgrading parts of the region to a strong risk if confidence increases that the wildfire smoke will not significantly affect thunderstorm development.

The widespread severe risk includes Ottawa, Cornwall, Brockville, Smiths Falls, Renfrew, Bancroft, Kingston, Belleville, Pembroke, Algonquin Park, Peterborough, Oshawa, Newmarket, Barrie, Orillia, Bracebridge and Huntsville.

The main hazards include localized damaging hail up to golf ball size, although most hailstones are expected to range from quarter to toonie size. Damaging wind gusts will also be possible.

An isolated tornado cannot be ruled out, particularly through the Ottawa Valley and in areas east of Lake Simcoe.

A conditional widespread severe risk covers Deep Southwestern Ontario and extends along the Lake Erie shoreline into the Niagara Region.

This risk depends on the wildfire smoke holding off or having less of an impact later in the day, allowing the atmosphere to become unstable enough for thunderstorms to develop.

If storms can form, the environment could support all severe weather hazards, including hail up to the size of Timbits, damaging wind gusts and an isolated tornado.

Elsewhere across Southern Ontario, isolated thunderstorms could produce damaging wind gusts and hail up to the size of quarters.

Localized flooding may also become an issue with any of these storms, as some could move slowly or repeatedly track over the same area for several hours.

August 08, 2026

Weekend Severe Storm Risk Targets Southern Ontario Including the Greater Toronto Area on Saturday

August 08, 2026/ Brennen Perry

Hot and humid conditions have returned to Southern Ontario, helping fuel isolated pop-up thunderstorms over the past few days.

While most of these storms have remained below severe limits, that is expected to change on Saturday as a more widespread severe thunderstorm threat develops across the region.

The strongest risk zone on Saturday will extend from the London area northward toward Lake Simcoe. Thunderstorms are expected to develop during the afternoon and early evening before tracking eastward into the Greater Toronto Area and communities along the Lake Ontario shoreline.

Storms will likely begin as discrete cells, meaning they will initially develop separately instead of forming one organized line. This type of storm development could support all severe hazards, including damaging wind gusts, large hail and an isolated tornado threat.

The tornado threat remains somewhat uncertain and will depend heavily on exactly where storms develop.

Join Us on YouTube for Storm Coverage:

We'll be providing comprehensive live coverage of any storms that develop Saturday on our YouTube channel. Our team will be tracking storms in real time with live radar analysis, warnings, and storm reports, so if severe weather threatens your area, be sure to join us live to help stay informed.

Based on the latest data, the most favourable environment for tornado development appears to be focused along the Lake Erie shoreline near Chatham, extending through London, Kitchener and northward toward Lake Simcoe.

Any storm that can become established within this corridor while remaining isolated could produce strong wind gusts, large hail and possibly a tornado. The tornado threat should become clearer on Saturday once we see how the morning storms evolve and what environment is left behind.

Later in the day, the storms are expected to merge into a more organized line or cluster as they track into the Golden Horseshoe and eventually Eastern Ontario.

This transition would make damaging wind gusts the primary concern, while the threat of large hail and tornadoes gradually becomes less prominent. However, brief spin-up tornadoes can occasionally occur within a line of storms, so the tornado risk may not disappear entirely.

There is still an important question mark surrounding Saturday’s severe threat due to the potential for morning thunderstorms.

As we often see on days with a stronger severe thunderstorm risk, morning convection can make or break the threat later in the day. Clouds and rainfall from these storms could limit daytime heating and reduce the amount of energy available for afternoon thunderstorm development.

Most models currently show the morning activity clearing Southern Ontario between approximately 11 a.m. and 1 p.m. While that timing is cutting it close, it should still leave enough time for the atmosphere to recover before the next round develops during the afternoon and early evening.

If the morning storms linger longer than expected, they could use up much of the available storm energy and reduce the strength or coverage of the afternoon severe threat.

On the other hand, if the morning activity clears earlier and sunshine quickly returns, the atmosphere could recharge rapidly. This would allow the afternoon storms to take full advantage of the hot and humid conditions during the peak of daytime heating.

The main focus of Saturday’s severe thunderstorm risk is Central Ontario, particularly around Lake Simcoe, extending southward into Southwestern Ontario.

This risk zone includes Bracebridge, Peterborough, Orillia, Midland, Barrie, Collingwood, Orangeville, Newmarket, Toronto, Hamilton, Guelph, Kitchener, Woodstock, Brantford, London, Grand Bend, Sarnia and Chatham.

These areas are included in a widespread severe thunderstorm risk, which is level 2 out of 5 on our scale.

The main threats will be damaging wind gusts and hail up to the size of a toonie. An isolated tornado cannot be ruled out, particularly while storms remain discrete during the earlier stages of development.

Flash flooding could also become a significant concern. Many areas have already received substantial rainfall over the past few weeks, leaving the ground saturated and less able to absorb additional water.

Thunderstorms could produce torrential rainfall over a short period, especially if they repeatedly track over the same locations. This may lead to localized flooding in low-lying areas, poor drainage locations and urban communities.

The rest of Southern Ontario is included in an isolated severe thunderstorm risk, which is level 1 out of 5.

This includes Deep Southwestern Ontario around Windsor and Leamington, the Niagara Region, northern portions of Central Ontario and much of Eastern Ontario.

Isolated thunderstorms will be possible in these areas, including some pop-up activity across Eastern Ontario during the afternoon ahead of the main storm zone.

However, it remains questionable whether the environment in these areas will support anything more than localized pulse thunderstorms. While a few storms could briefly approach severe limits, the most serious and widespread threat is expected to remain focused from Southwestern Ontario through the Lake Simcoe area and into the Greater Toronto Area.

August 07, 2026

Massive Upgrade to Environment Canada's Warning System Coming as Early as Tuesday

August 07, 2026/ Adam Skinner

For as long as Canadians have received Tornado Warnings on their phones, those warnings have been shaped by lines that have nothing to do with weather.

Municipal boundaries. County lines. Forecast regions drawn decades ago for the convenience of the people issuing the alert, not the people receiving it. When a supercell crossed into one of those zones, everyone inside got the same alert: the family directly under the storm and the family 60 kilometres away on the other side of the region, watching a sunset.

That is about to end.

Environment Canada is finally replacing the giant zone-based Tornado Warnings and Severe Thunderstorm Warnings with much more focused storm-based warnings, which forecasters will hand-draw based on the storm's location and direction. We say 'finally' because the US implemented storm-based warnings 19 years ago on October 1st, 2007. Here at Instant Weather, we've sent custom notifications for dangerous storms using hand-drawn polygons for the past 10 years. Additionally, Environment Canada has been attempting to launch the new system for two years but downstream setbacks have forced several delays. Nonetheless, it’s better late than never and we certainly appreciate how important it is to get a change like this right when lives depend on it.

The new system, called CAM or Convective Alert Modernization is planned to launch on Tuesday, August 11th, 2026. However, the Environment Canada team responsible for launching it told Instant Weather in an email that the launch is largely weather dependent and the 12th and 13th are backup dates. Additionally, there's a small chance unforeseen technical setbacks could delay it even further but from what we're hearing, it's looking very promising that the new system will launch sometime between Tuesday and Thursday.

HOW ABOUT TV AND RADIO ALERTS?

HYPOTHETICAL EXAMPLE OF HOW STORM BASED ALERTS WILL ONLY SHOW MARGINAL IMPROVEMENTS FOR TV AND RADIO ALERTING

The amazing news: this change is expected to reduce the number of cell phones automatically receiving Tornado Warnings and red-level Severe Thunderstorm Warnings by roughly 70%, with the greatest improvements seen by those in rural communities where legacy alert zones are massive.

The not-so-good news: Radio and T.V. alerts will only see very marginal improvements. This is still a major issue as broadcast alerts can notify people more than 100 km away from the path of the storm in some circumstances.

Long story short, if you do receive a Tornado Warning or red-level Severe Thunderstorm Warning on your T.V. or Radio but not on your phone, take the warning seriously and make sure to check the storm-based polygon to determine whether your location is in the storm’s warned path. You can check using our free app Instant Weather or Environment Canada's website, for example to quickly determine this.

This is the most consequential change to Canadian storm alerts in a generation, and it did not arrive a moment too soon.

THE TIME FOR CHANGE IS NOW

The case for storm-based warnings has been building for decades and this above-average tornado season made it hard to ignore.

Canada is on pace for an above-average tornado year. By August 7th, 87 tornadoes had been confirmed nationally, more than 70 of them across Alberta, Saskatchewan and Manitoba. Manitoba alone had logged 10 by mid-July, against a 30-year average of 8.5 for an entire season, according to the Northern Tornadoes Project.

But warnings have been outpacing the tornadoes, and this mismatch has been frustrating some Canadians.

In June, phones across southern Manitoba lit up repeatedly during a single evening of storms. Some Winnipeg residents reported receiving upwards of 20 alerts. Two tornadoes did touch down that night, 30 to 50 kilometres south of the city. For people in Winnipeg, the threat was never close. Environment Canada later confirmed it was investigating why some recipients received the same alert multiple times.

WHAT ACTUALLY IS A POLYGON?

It's actually simpler than the name suggests.

Instead of selecting large zone-based regions when issuing a warning, an Environment Canada forecaster will now draw a small shape directly on a map: a box enclosing where the storm is now and where it is going. Forecasters then use that shape to target the alert, which is pushed to cell towers.

Something important to consider: these new hand-drawn warnings will continue to notify phones outside the actual alert region if their phone is reachable by the cell phone towers inside the alert. However, since alert regions will be 75% smaller, the number of people alerted inside and outside of the alert will decrease significantly. There can also be a benefit to some people just outside the polygon being notified, particularly if they are travelling toward the warned area.

Importantly, Environment Canada is applying this only to Severe Thunderstorm Warnings and Tornado Warnings. Every other alert type, including winter storm warnings, rainfall warnings, heat warnings, snow squall warnings, air quality statements, etc., continues to be issued using the legacy, zone-based areas. This is a surgical change to the two alert types where minutes and kilometres matter most.

ARE LEGACY ALERT ZONES STILL ACTIVE?

For broadcasters, app developers, emergency managers and anyone else consuming Environment Canada's alert feed, this is the section that matters. The technical documentation Environment Canada has released is unusually specific, and its design decisions are worth understanding.

The zone blocks are not going away. This is the single most important compatibility fact. The new free-form polygon arrives as an additional product within the alert message. The existing, large county-based and municipality-based zone alerts continue to exist exactly as they do today, so systems not ready for storm-based warnings will keep working. It is an addition, not a replacement.

Based on Environment Canada’s documentation, two versions of the same Tornado Warnings and Severe Thunderstorm Warnings will be issued simultaneously. One will be issued for the legacy zone-based regions to support those slow to adopt to the new system and as a fallback, and an additional, more accurate storm-based warning will also be issued.

Thankfully, and this part is huge: AlertReady, the system that pushes Amber Alerts, Tornado Warnings, etc., directly to your cell phone will use the drastically smaller storm-based warning, not the legacy zone-based warnings. Only in the case of a storm-based warning failure will the legacy system be used.

WHAT POLYGONS WILL NOT FIX

Precision within a Tornado Warning region is not the same as precision in tornado detection, and it is worth clarifying that gap.

Environment Canada's upgraded S-Band radars are a significant improvement over the replaced C-Band radars. However, due to technical choices made by Environment Canada, detecting small areas of rotation in high-shear environments is a huge problem because of noisy velocity (wind) data.

The math behind false alarms is also unforgiving. According to historical data, like that produced by the Northern Tornadoes Project, less than 10% of severe thunderstorms produce a tornado. Forecasters will continue to warn on storms that never produce, because the alternative, waiting for confirmation, costs lives. What polygons change is who receives those false alarms. Under the old system, an entire region dealt with every false alarm. Under the new one, only the people genuinely downstream do. That is how a warning system rebuilds credibility: not necessarily by eliminating false alarms, but by exposing far fewer unaffected people to them.

And a smaller warning area carries its own risk. A tighter polygon means more people just outside the line, people who, under the old system, would have been warned. Storms deviate. Tornadoes form on the flank. No alert on your phone is not the same as no threat near you, and it never has been.

WHAT TO DO ABOUT IT

Keep watching the sky and the radar, not just your notifications. Targeted alerting works when it is paired with situational awareness, not when it replaces it.

Get alerts from at least two trusted sources, as no system is perfect.

And when your phone does go off, take it seriously. Starting next week, the Tornado Warning or red-level Severe Thunderstorm Warning that reaches you via AlertReady is far more likely to affect your community than in previous years.

Welcome to the future of severe weather alerting, Canada.

July 28, 2026

Strong Severe Thunderstorms with Tornado Risk Once Again Target Edmonton and Parts of Central & Northern Alberta Tuesday

July 28, 2026/ Alannah Campbell

It has been a seemingly never-ending pattern of severe weather for Central and Northern Alberta lately and unfortunately, that pattern will continue today. We are once again looking at the possibility of strong severe thunderstorms that could impact parts of Central and Northern Alberta, including Edmonton, beginning this afternoon and continuing through the evening.

The environment will be favourable for the development of supercell thunderstorms today. There will be plenty support for these storms, with CAPE values exceeding 2000J/kg in some areas, along with a considerable amount of shear and moisture. A low that will move through the province this afternoon will then be the trigger that causes the storms to develop.

Thunderstorms are expected to fire up early this afternoon in the Foothills. From there, they will track eastward, into the most favourable environment by the late afternoon and continuing through the evening. The greatest severe threat will be in the 5-10pm timeframe and those in the Edmonton area could see severe weather in the window of 6-9pm.

As we get later into the evening, after around 10pm, the storms are expected to weaken as they gradually continue east towards the Saskatchewan border and most thunderstorm activity should end by midnight.

***Hourly Precipitation at 5Pm MDt, courtesy of weatherbell.***

The strong supercell storms this evening could have the potential to produce very large hail that could be as large as tennis balls, damaging wind gusts in excess of 100km/h, and very heavy rain. The rain will be a concern particularly in Edmonton, which is just inside the area at risk for the strongest storms, since there has been considerable flooding after every thunderstorm that has tracked through the city lately.

There will also be a widespread risk for severe thunderstorms that are expected to be slightly weaker, in an area that surrounds the highest risk. This covers Hinton, High Prairie, Slave Lake, Cold Lake, and Camrose, with Rocky Mountain House and Fort McMurray just inside the risk area.

The storms in this region will likely still be able to produce damaging wind gusts above 100km/h, but the hail associated with them is expected to be a bit smaller, maxing out at the size of a golf ball.

Beyond this region, there is a much more isolated severe risk in an area that covers Red Deer, Jasper, Grande Prairie, Peace River, and north to the Northwest Territories border.

It’s important to note that today’s thunderstorms will have a tornado risk associated with them, but this risk is the most significant for the area marked by hatching on our forecast map, where the strongest storms are expected. This includes Edmonton, Edson, Whitecourt, and Lac La Biche.

With the threat of tornadoes today, please make sure that you have a plan in place in the event that severe weather approaches your area. Make sure to have all of your devices charged and that you have more than one way to receive critical weather alerts.

It’s likely that we will be going live later this afternoon, as the storms start to strengthen, so be sure to tune in at instantweather.ca/live.

July 27, 2026

Multiple Rounds of Severe Thunderstorms Expected Across Southern Ontario on Monday

July 27, 2026/ Brennen Perry

After a relatively quiet stretch of weather, Southern Ontario is heading into a much more active pattern on Monday as multiple rounds of thunderstorms threaten a wide swath of the province. Some of these storms could become severe, bringing the risk of damaging wind gusts, large hail and the potential for one or two tornadoes.

The first round of storms has already developed early this afternoon, with a cluster of thunderstorms producing damaging wind gusts as they tracked inland from Lake Huron into parts of the London area. While this initial activity is ongoing, it is only the beginning of what could become a busy weather day across Southern Ontario.

Additional thunderstorms are expected to develop through the afternoon across Southwestern Ontario before spreading into portions of Central Ontario, particularly around the Lake Simcoe region. Exactly where these storms form remains uncertain, as forecast models continue to struggle with pinpointing the locations where new storms will develop.

Track the storms with us on YouTube

The severe weather threat is expected to continue through the afternoon and early evening, when daytime heating will provide the greatest amount of energy for storm development. Storms may continue well into the evening and persist into the early overnight hours, although the overall severe threat should gradually diminish after midnight as the atmosphere begins to stabilize.

Periods of rain and embedded thunderstorms are expected to linger into Tuesday morning before the system finally begins to move out of the region. Another round of potentially severe storms could affect Eastern Ontario on Tuesday afternoon.

The greatest concern remains across Deep Southwestern Ontario and communities along the Lake Huron shoreline, including Goderich, Sarnia, London, Chatham, Leamington and Windsor.

We have placed this region under a ‘Strong’ severe weather risk. Storms that develop here will have the potential to produce widespread damaging wind gusts capable of downing trees and power lines, hail ranging from toonie-sized up to Timbit-sized, along with the possibility of one or two tornadoes. Torrential rainfall may also lead to localized flash flooding, particularly where multiple thunderstorms repeatedly move over the same communities in a short period of time.

Further north and east, a ‘Widespread’ severe risk stretches across much of Southern and Central Ontario, including Kitchener, Guelph, Hamilton, Toronto, Barrie, Niagara, Hanover, Collingwood and Owen Sound.

The primary threats in this region will be damaging wind gusts and hail up to the size of toonies. While the tornado risk is lower than in Southwestern Ontario, an isolated tornado cannot be completely ruled out if a storm is able to remain isolated and tap into the favourable atmospheric conditions.

An ‘Isolated’ severe weather risk covers the remainder of Central Ontario, including Peterborough, Muskoka, Parry Sound and Algonquin Park. This risk also extends into parts of Northeastern Ontario, including Sudbury and North Bay.

Only a few storms are expected to develop in these areas, but any storm that does form could still briefly reach severe limits with strong wind gusts, hail and frequent lightning.

Given the uncertainty surrounding exactly where storms will develop, everyone across Southern Ontario should keep a close eye on the forecast throughout the day. Conditions can change quickly, and warnings may be issued with little lead time once thunderstorms begin to intensify.

We’ll be tracking every storm as it develops with live coverage on our YouTube channel, along with real-time updates through the free Instant Weather app. If you live anywhere within the risk areas, now is a good time to make sure notifications are enabled so you can receive notifications the moment they are issued.

July 26, 2026

Ontario Faces 100 km/h Winds, 4 cm Hail and Up to 60 mm of Rain as Heat Builds This Week

July 26, 2026/ Adam Skinner

Ontario faces a stormy and increasingly hot week, with 100 km/h wind gusts, 4 cm hail and 50 mm of rain possible Monday before parts of southern Ontario face up to 60 mm Tuesday. Northwestern Ontario could reach 31°C by midweek.

July 25, 2026

Widespread Severe Thunderstorm Threat in Southwestern Ontario Sunday With Timbit-Sized Hail and Damaging Winds Possible

July 25, 2026/ Brennen Perry

After a few days of below-seasonal temperatures across Southern Ontario, with daytime highs making it feel more like early September, temperatures are back on the upswing over the next few days.

The cooler weather also brought a quieter period for thunderstorm activity, with our last widespread severe weather event occurring on Tuesday.

While no extreme heat is expected in the near future, temperatures will climb slightly above seasonal levels to start the week. Many areas will see daytime highs in the upper 20s or even low 30s on Monday.

That will be enough to increase instability and bring the potential for multiple rounds of thunderstorms beginning Sunday.

Sunday’s severe thunderstorm threat is expected to be mostly confined to Deep Southwestern Ontario, including Windsor, Chatham and Sarnia. Moderate instability combined with strengthening wind shear could create an environment capable of supporting severe storms.

However, there is still some uncertainty about whether storms will develop and exactly where they might form, as there is no obvious trigger such as a cold front.

Instead, storm development will depend on whether isolated cells can form along smaller-scale boundaries, including lake breezes.

Lake breeze-driven pop-up storms will be possible across Southern Ontario. However, outside of the Lake Erie shoreline and Deep Southwestern Ontario, the environment is not expected to be strong enough to support anything more than isolated, non-severe storms.

Join Us on YouTube for Storm Coverage:

We'll be providing comprehensive live coverage of any storms that develop Sunday on our YouTube channel. Our team will be tracking storms in real time with live radar analysis, warnings, and storm reports, so if severe weather threatens your area, be sure to join us live to help stay informed.

The focus is expected to remain on Southwestern Ontario on Monday, although more widespread thunderstorm development appears increasingly likely as a cold front potentially sweeps through later in the day.

The timing of that cold front is still uncertain and will have a significant effect on the severity of Monday’s storms. A later arrival during the prime hours of daytime heating would likely result in a stronger severe weather threat compared to an evening arrival.

At this point, a wide swath of Southwestern Ontario, including Windsor, Sarnia, London, Hamilton, Kitchener, Goderich, Hanover and Owen Sound, could see severe storms on Monday.

There is also an isolated severe risk extending into the Greater Toronto Area and portions of Central and Northeastern Ontario, including Barrie, Peterborough, Muskoka, Parry Sound, North Bay and Sudbury.

We’ll have more details about Monday’s storm risk, including the expected hazards and timing, in a separate forecast.

For Sunday, isolated thunderstorm activity is possible across Southern Ontario beginning during the early afternoon and continuing into the evening.

Most of these storms are expected to remain below severe levels, with small hail, strong wind gusts and heavy rainfall as the main threats.

The greatest concern for severe weather will be across Deep Southwestern Ontario, extending along the northern Lake Erie shoreline and into the Hamilton and Niagara regions.

If lake breeze boundaries can trigger storms in this area, the environment could support a few storms reaching severe levels. Damaging wind gusts and large hail would be the primary threats.

Weather models often struggle to predict lake breeze-driven pop-up storms. However, the latest data has consistently focused on the Windsor to Leamington corridor as the area most likely to see a storm between 5 and 9 p.m.

Additional thunderstorm activity could develop farther north and east, including around Sarnia, Chatham, London and Hamilton, although models are less certain about storm development in these areas.

The severe weather risk should quickly diminish after sunset, around 9 p.m., as storms lose the daytime heating that helped fuel their development.

Large hail and damaging wind gusts will be the primary threats from any severe storms that develop across Deep Southwestern Ontario on Sunday.

However, increasing wind shear during the early evening could create a narrow window capable of supporting a brief spin-up and an isolated tornado.

The latest model data shows an elevated Significant Tornado Parameter across Essex County. This parameter highlights areas where the atmospheric ingredients could support tornado development.

The most favourable environment appears to be concentrated over Essex County, although it may extend into Chatham-Kent and along the Lake Erie shoreline.

We have a ‘widespread’ severe risk for Windsor, Leamington, Chatham and Sarnia. This risk is driven by the potential for damaging wind gusts and hail up to the size of a Timbit. An isolated tornado cannot be ruled out.

There is an ‘isolated’ severe risk farther north and east along the Lake Erie shoreline, including Grand Bend, London, St. Thomas, Woodstock, Tillsonburg, Brantford, Hamilton and Niagara Falls.

A few storms in this area could reach marginally severe levels, producing hail up to the size of a quarter and isolated damaging wind gusts.

Across the rest of Southern Ontario, isolated non-severe thunderstorms are possible throughout the afternoon and early evening, including across the Golden Horseshoe and portions of Central and Eastern Ontario.

While these storms are expected to remain below severe levels, anyone planning to be outside or on the water should closely monitor the radar.

Be prepared to seek shelter indoors if a storm approaches, as even non-severe thunderstorms can pose a significant safety risk due to lightning, strong wind gusts and small hail.

July 25, 2026

Wildfire Smoke Could Hinder Severe Thunderstorm and Tornado Threat for Edmonton and Parts of Central & Northern Alberta Saturday

July 25, 2026/ Alannah Campbell

The risk for severe weather returns to Edmonton and parts of Central and Northern Alberta with the possibility of severe thunderstorms across the region beginning this afternoon and continuing into the overnight hours.

In yesterday’s thunderstorm outlook from Environment Canada, they had a High Risk for this region. That High Risk has since been downgraded to a Moderate Risk, likely due to the impact that wildfire smoke will have on the potential development of thunderstorms later today.

Smoke from wildfires in British Columbia and the US Pacific Northwest has been significantly impacting air quality at ground level across Alberta over the past few days. However, the presence of smoke higher up in the atmosphere can greatly influence our weather conditions.

***Modelled Vertically Integrated Smoke at of 12pm MDT, Courtesy of*** ***WMI***.

When we have thick smoke throughout the atmosphere, not as much sunlight is able to reach the ground and as a result, it end ups being a few degrees cooler at the surface than expected. A decrease in surface heating while the air aloft is able to heat up also greatly reduces the instability and creates a capping inversion that could block thunderstorm development.

Despite the smoke, there is still a chance that we could see some severe thunderstorms fire up today, but it is not a guarantee. Models are showing that a decent amount of instability could still be available, along with plenty of moisture and shear, to fuel thunderstorms if they are able to break through the cap.

Thunderstorm activity could initiate early this afternoon, particularly in the Foothills, and storms that develop are expected to gradually track northeastward through the remainder of the afternoon and into the evening and overnight hours, with additional storms possibly popping up through this period.

The storms that may end up forming today will have the potential to become severe across parts of Central and Northern Alberta, in the area in yellow on our forecast map. In this region, the storms may be able to produce large hail up to the size of tennis balls, damaging wind gusts above 100km/h, and heavy rain. The hatched area on the map, which includes Edmonton, Red Deer, Rocky Mountain House, and Edson, will also have an isolated tornado risk.

Today’s severe weather risk could end up being a bust as a result of the wildfire smoke. However, with Edmonton potentially in the bullseye with a tornado risk, we will certainly be keeping a close on how things come together this afternoon.

July 24, 2026

Winnipeg & Southeastern Manitoba Under Tornado Threat Friday, but Storm Development is Questionable

July 24, 2026/ Alannah Campbell

A strong severe weather risk returns to Southeastern Manitoba later today, but the entire situation is very questionable and there’s a possibility that there are no storms at all in this region.

The low that has been tracking across the Northern Prairies continues to make its way through Northern Manitoba this morning and it will move into Northern Ontario later today. Thunderstorms were triggered by a trough behind the warm front of this low in Northern Alberta and Saskatchewan yesterday and they extended into Southern Saskatchewan and into Manitoba overnight.

These storms are continuing across Southern Manitoba this morning, some of which have become severe, and this is where the first question mark for later development arises.

In order for additional thunderstorms to initiate later, this morning’s storms will have to clear out of the area early enough for sufficient surface heating to occur. If these storms do manage to exit the region early enough, the environment will be well suited for stronger severe thunderstorms to then begin to develop later this afternoon and into the evening.

The position of the trough that has been triggering thunderstorms will also play a large role in when and where more storms might initiate. In this morning’s latest runs, most short-term weather models are hinting at the trough being positioned in Northern Ontario by the time more thunderstorms fire up, which would keep the greatest severe threat to the east.

If everything manages to come together, with the morning storms clearing early and the trough remaining in Manitoba later this afternoon, there is a distinct possibility that some strong thunderstorms could impact Southeastern Manitoba through the evening. Storms that could affect this region will have potential to produce some very large hail, especially to the east of the Red River Valley. There will also be the risk of damaging wind gusts that could exceed 100km/h, torrential downpours and even a tornado.

While today’s severe weather risk could very easily end up being a bust, it’ll be a good idea to be prepared in the event that strong thunderstorms do end up forming. Make sure to have your devices all charged and that you have multiple ways to receive weather alerts and updates.

If the severe risk manages to materialize in Manitoba later on, we will very likely be live-streaming coverage of the storms, so be sure to join us at www.instantweather.ca/live!

July 23, 2026

Widespread Severe Thunderstorm Risk Across the Northern Prairies Thursday; Tornado Threat in Northern Saskatchewan

July 23, 2026/ Alannah Campbell

Today, there will be the widespread potential for severe thunderstorms across Northern Saskatchewan and Manitoba, and into parts of Northern Alberta. Meanwhile, most of the rest of the Prairies will be under a more isolated risk.

A low that is over Northern Alberta this morning will move into Saskatchewan this afternoon and its cold front will be the trigger for thunderstorm development. Although there won’t be a great deal of instability, with CAPE values below 1000J/kg for most of the region, there will be more than enough shear to still support thunderstorms once they form, especially for more southern areas.

We are already seeing some non-severe thunderstorms this morning in Northeastern Alberta and Northwestern Saskatchewan. It’s possible that one or two of these storms could become severe, especially if they can persist into the afternoon.

***Hourly Precipitation at 7Pm MDT/CST, 8pm CDT , courtesy of weatherbell.***

It’s during the afternoon that we are expecting to see additional development across the Northern regions of all three Prairie provinces, which will gradually track eastward with the low through the evening and overnight.

For the most part, we’re expecting that these will be garden variety severe thunderstorms across the region, with the main threat being strong wind gusts that could exceed 100km/h along with the possibility of up to toonie size hail and heavy rain.

There is, however, a slightly stronger severe risk in parts of Northern Saskatchewan and crossing the border into Alberta. This particular area, which includes Cold Lake, Meadow Lake, and Prince Albert, could potentially see storms that are capable of producing up to golf ball size hail, as well as an isolated tornado.

The presence of wildfire smoke in the atmosphere could certainly hinder thunderstorm development today, especially where the smoke is much thicker, closer to the Northwest Territories border. The good news is that we’re expecting today’s thunderstorms to be very moisture-laden, and there is also the possibility of widespread heavy rain not associated with thunderstorm activity. This will be beneficial for firefighting efforts across Northern Saskatchewan and Manitoba, as long as no additional fires are ignited by lightning strikes.

July 22, 2026

Two EF2 Tornadoes Confirmed Near Rocky Mountain House, Alberta After Destructive July 18th Storm

July 22, 2026/ Adam Skinner

Two EF2 tornadoes developed just 18 minutes apart near Rocky Mountain House on July 18, producing estimated peak winds of 190 km/h and more than 18 kilometres of combined damage. Northern Tornadoes Project surveys documented destroyed outbuildings, roof damage and wide swaths of downed trees.

July 21, 2026

Strong Severe Storm Risk Targets Southern Ontario Tuesday With Damaging Winds, Toonie-Sized Hail and Tornadoes Possible

July 21, 2026/ Brennen Perry

After an active storm day on Saturday brought a rare tornado warning to the Greater Toronto Area along with several reports of damaging winds, Southern Ontario is set to face another severe thunderstorm threat on Tuesday.

The strongest risk appears to be focused along the Highway 401 corridor, stretching from London through the Greater Toronto Area and into Kingston. Storms during the afternoon and early evening could bring widespread damaging wind gusts, up to toonie-sized hail and one or two tornadoes.

Before the main event, morning storms may provide an early wake-up call for parts of Southwestern Ontario and the Golden Horseshoe as a complex of storms tracks into the region from Michigan during the early morning hours on Tuesday.

While most of these storms should remain non-severe, some stronger pockets could bring marginally severe wind gusts, large hail and even a very low tornado threat.

In the wake of Tuesday’s storm threat, which is expected to end by the evening, a cold front will usher much cooler air into Southern Ontario.

Daytime highs on Wednesday could struggle to reach the 20°C mark, making it feel more like early autumn. You may find yourself reaching for the comfort of a pumpkin spice latte instead of a cold summer refreshment!

A mesoscale convective system (MCS) over Michigan is expected to slide into Southern Ontario overnight and early Tuesday morning, first affecting areas east of Lake Huron between approximately 1 and 3 a.m.

As the complex moves inland, some stronger pockets could produce wind gusts exceeding 90 km/h and hail up to the size of a quarter.

There is some uncertainty over how strong this storm complex will remain as it tracks eastward into Central Ontario and the Golden Horseshoe between approximately 3 and 6 a.m.

Weather models tend to struggle with these types of systems. They can sometimes generate their own energy and maintain or strengthen themselves in an environment that would otherwise appear unsupportive of severe weather.

A brief spin-up capable of producing an isolated tornado cannot be completely ruled out, although this is considered very unlikely given the overnight timing.

The marginal severe threat associated with this complex could continue into the mid-morning hours as it reaches the Niagara Region and communities along the northern Lake Ontario shoreline.

The morning storms are expected to clear out by late morning, potentially setting the stage for a more widespread and intense severe weather threat beginning early Tuesday afternoon.

There is still some uncertainty surrounding the timing of the afternoon threat, especially since multiple rounds of storms may be possible.

The afternoon risk will also depend heavily on how quickly the morning storms move out. This will determine how much daytime heating can occur before the next round develops, likely along a cold front moving through the region during the afternoon.

Based on the latest data, the greatest chance for storm development appears to be along a line stretching from Sarnia through London and into the Greater Toronto Area, generally following the Highway 401 corridor.

Storms could begin developing during the early afternoon before tracking southeast toward the Lake Erie and Lake Ontario shorelines. This would bring the threat into Hamilton, the Niagara Region, Prince Edward County and Kingston later in the afternoon.

In addition to the cold front, a warm front will track through Central and Eastern Ontario during the afternoon. This could spark isolated severe storms around Lake Simcoe and into the Ottawa Valley.

However, the strongest environment is expected to develop around the Lake Ontario and Lake Erie shorelines. These areas should experience several hours of daytime heating after the warm front moves through during the morning, adding further instability before the cold front sweeps through later in the day.

The timing of the cold front will be critical. If it moves through too early, substantial storm development may not occur until the front begins moving south of the border, decreasing the risk to our side of the border.

If it is delayed, storms could begin developing farther northwest and have more of Southern Ontario to track across during the peak of daytime heating, potentially increasing the overall severe weather threat.

Based on the potential for widespread damaging wind gusts, we have introduced a ‘strong’ severe risk for London, St. Thomas, Woodstock, Tillsonburg, Brantford, Kitchener, Hamilton, Niagara, Guelph, Mississauga, Toronto, Newmarket, Oshawa, Belleville, Picton and Kingston.

Other hazards within this zone include hail up to the size of a toonie and the potential for one or two tornadoes.

Localized flash flooding may also be a concern, particularly in urban areas that receive multiple rounds of storms within a short period.

Outside the strongest risk zone, we have an expansive ‘widespread’ risk covering the remainder of Southwestern Ontario, southern portions of Central Ontario and the Ottawa Valley.

This includes Windsor, Chatham, Sarnia, Goderich, Hanover, Orangeville, Barrie, Peterborough, Bancroft, Pembroke, Renfrew, Smiths Falls, Ottawa, Brockville and Cornwall.

Storm hazards in this zone include damaging wind gusts, hail up to the size of a toonie and the possibility of an isolated tornado.

For the Bruce Peninsula and areas east of Georgian Bay, including Muskoka and Algonquin Park, we have introduced an ‘isolated’ severe risk. However, most of the severe thunderstorm activity is expected to remain south and east of this region.

After a second cold front moves through late Tuesday evening, it will usher in a much fresher air mass across Southern Ontario.

Morning temperatures on Wednesday could fall into the upper single digits across some of the more elevated portions of Central Ontario.

It may continue to feel like pumpkin spice season throughout Wednesday, with daytime highs in many areas struggling to climb above 20°C.

Deep Southwestern Ontario, communities along the Lake Ontario shoreline and parts of Eastern Ontario currently have the best chance of reaching the low 20s on Wednesday.

The coldest conditions will be found across the higher elevations of the Dundalk Highlands and into cottage country, where daytime highs on Wednesday could remain in the upper teens.

Those temperatures would be more typical of a crisp autumn day in early September than the middle of summer!

Thankfully, the cooldown should be short-lived, with more seasonal temperatures expected to return by the end of the week and into the weekend.

July 18, 2026

Dangerous Tornadic Supercells Capable of Massive Hail & Destructive Wind Gusts Possible Northeast of Edmonton Saturday; Strong Severe Thunderstorm Risk Extends Across Alberta & Saskatchewan

July 18, 2026/ Alannah Campbell

The week of daily severe weather risk in Alberta continues on Saturday, and much of Saskatchewan, with the greatest threat we’ve seen so far this week.

Not only are we looking at the possibility of strong severe thunderstorms across a considerable stretch of both Alberta and Saskatchewan today, but there is also the risk for some significantly strong storms to the east and northeast of Edmonton, in an area that includes Vegreville and St. Paul.

Today’s environment will be primed for the formation of strong supercell thunderstorms.

Models are showing that there will be an incredible amount of instability across the region today, with well over 3000J/kg of CAPE (Convective Available Potential Energy) expected for the Edmonton area. CAPE values of this magnitude are very uncommon for areas this far north, which indicates how strong of a risk we are truly looking at.

Dew points in the upper teens to low 20s today will provide plenty of moisture. Combined with the significant amount of shear that’s expected through the atmosphere, supercell storms will be easily supported.

Overall, we’re looking at a very dangerous setup that would look more at home in the Great Plains of the United States, not in Central Alberta and Saskatchewan.

A low that is set to develop this afternoon, and its associated cold front, will be the trigger for today’s severe weather. The location of this low will be the key to where the very strong thunderstorms will end up impacting.

As it stands, it appears that the low will set up over Edmonton, which would bring the greatest severe threat to areas northeast and east of the city.

***Future Surface weather map with the positions of highs, lows, and fronts displayed for 6pm MDT/CST on Saturday, courtesy of*** ***the national weather service***.

There have already been some severe thunderstorms in Northern Alberta and Southeastern Saskatchewan this morning, but these will just be a precursor of what’s to come.

Additional storms could begin to initiate early this afternoon, mostly in the Foothills, but there could be some isolated development across Central Alberta and into Saskatchewan. As we progress through the afternoon, we are expecting to see more storms develop, all of which will move along a mostly northeastward trajectory.

The greatest severe threat will be through in the evening and into the overnight hours, as the storms encounter their most ideal environmental conditions. The strongest of these storms will likely impact areas to the northeast of Edmonton later in the evening, approximately from 10pm to midnight, give or take an hour.

Through the overnight hours, the storms will eventually weaken, but there will still be a slight severe risk that continues into the pre-dawn hours.

***Hourly Precipitation at 11Pm MDT/CST, courtesy of weatherbell.***

As we’ve mentioned, the area to the northeast of Edmonton is under a significant severe weather threat today. The storms that hit this region could potentially produce massive baseball size hail and destructive wind gusts that could be upwards of 130km/h, possibly even higher.

There is also a strong severe risk the covers a large portion of Central Alberta and Saskatchewan, that also extends into Northern parts of both provinces.

The entirety of the area under both the Strong and Significant severe risks today will also have the threat of tornadoes developing. The greatest risk for multiple, possibly strong, tornadoes, however, will be in that Significant risk as well as the surrounding area.

This could end up being a very dangerous day so it is crucial to have a plan in place in the event of tornado warning for your area. You’ll need to know where the best place to take shelter is: the most interior room of the lowest floor, away from any windows.

It’s also very important to have all of your devices charged and to have multiple ways to receive weather alerts.

We have already begun live streaming the severe weather ongoing in Southern Ontario and we will be extending our coverage to include Alberta and Saskatchewan once things start to fire up later. Be sure to join us as www.instantweather.ca/live!

July 18, 2026

GTA in the Bullseye as Southern Ontario Faces Significant Storm Risk With Tornadoes, Destructive Winds and Timbit-Sized Hail Possible Saturday

July 18, 2026/ Brennen Perry

The persistent wildfire smoke that has blanketed Southern Ontario over the past several days is finally on the way out, but it will quickly be replaced by a very different threat.

A potentially significant severe weather event is expected across much of Southern Ontario on Saturday as a strong cold front sweeps through the region. The greatest risk is focused on the Greater Toronto Area and surrounding parts of the Golden Horseshoe, where an intense squall line could produce widespread destructive wind gusts, several tornadoes, large hail and flash flooding during the afternoon.

Toronto, Mississauga, Hamilton, Brampton, Vaughan, Oshawa and the surrounding region could be directly in the path of the most intense portion of the squall line.

Widespread wind damage and power outages will be possible if the squall line develops as currently expected. Flash flooding could also become a major concern across heavily urbanized areas, where torrential rainfall may quickly overwhelm drainage systems and flood roads or low-lying areas.

The severe threat will begin much earlier across cottage country, where isolated storms could develop as early as the late morning or around noon. These initial storms may have a greater chance of becoming supercells and producing tornadoes before they organize into a larger squall line.

This is especially concerning on a summer weekend when many people may be camping, boating or staying at cottages across Simcoe County, Muskoka, the Kawartha Lakes and Algonquin Park. Those in tents, trailers or boats could be particularly vulnerable to fast-moving storms producing destructive winds, large hail and tornadoes.

Anyone spending time in cottage country should have a reliable way to receive weather alerts, keep a close eye on the sky and identify a sturdy shelter before storms arrive. Cell service can be unreliable in some remote areas, so it is important to plan ahead rather than waiting for threatening weather to approach.

Join Us on YouTube for Storm Coverage:

The overall severe threat will begin with scattered morning storms before rapidly increasing around noon and continuing through the afternoon. However, the exact strength and placement of the event will depend on how quickly those morning storms move out and whether lingering wildfire smoke limits daytime heating in Eastern Ontario.

As we often see on days with a strong severe weather risk, there will be a morning storm component. Scattered storms are expected to develop from Lake Huron through areas east of Georgian Bay and into Algonquin Park between approximately 6 and 8 a.m.

While most of these storms should remain below severe limits due to their early timing, a few cells could still bring a marginal severe threat, with wind gusts approaching 90 km/h and hail up to the size of nickels.

More importantly, these storms will play a key role in determining how the severe threat unfolds later in the day. A cold front is expected to quickly follow the morning storms during the early afternoon.

If the morning activity lingers into the late morning, it could limit additional daytime heating before the cold front arrives. This would leave storms developing along the front with a less favourable environment that has already been worked over by the earlier storms.

Another important factor is the persistent wildfire smoke from Northern Ontario that has been locked over Southern Ontario during the past several days.

Current models suggest the smoke should clear out of most of Southern Ontario by late Saturday morning. Based on the latest upper-level smoke data, it should be mostly confined to Eastern Ontario by noon.

This means Southwestern and Central Ontario, along with the Golden Horseshoe, should have no problem warming up as long as the morning storms do not linger for too long.

Eastern Ontario is more uncertain. With smoke potentially lingering into the afternoon, it could filter out enough sunlight to limit daytime heating and inhibit storm development. We recently saw this happen during what had initially appeared to be a strong severe weather threat in Quebec last week.

While it is unlikely that smoke will significantly affect storm development elsewhere in Southern Ontario, any unexpected delay in clearing could reduce the severe threat in some of the stronger risk areas. This remains a possible bust scenario, although it appears unlikely based on the latest data.

The threat will begin to build around noon as a cluster of storms develops from Lake Huron through cottage country and into Algonquin Park. This cluster is expected to eventually organize into a strong squall line, but the storms may remain more isolated during the first few hours of development.

That could allow the strongest tornado potential during the early stages of the event to focus on portions of cottage country. Anyone camping or spending time outdoors should have a reliable way to receive tornado alerts and remain weather aware, as these storms could move quickly and arrive with little notice.

We may also see isolated cells develop ahead of the main line before eventually being absorbed as the cold front races toward them. These isolated storms could present a tornado threat across portions of Simcoe County, York Region and the Greater Toronto Area.

The latest Significant Tornado Parameter data, which highlights where the ingredients for tornado development may be strongest, focuses the greatest potential just west of Toronto around Kitchener, Orangeville and Barrie, extending northward into Bracebridge and Algonquin Park.

This parameter only shows where the environment may be supportive. Storms still need to develop and take advantage of those ingredients.

However, it suggests that any storms that do form could quickly present a tornado threat beginning as early as noon, with the risk continuing to build through the early afternoon.

By the middle of the afternoon, a maturing squall line attached to the cold front is expected to sweep southeastward into a highly favourable severe weather environment.

This environment will extend from Sarnia through Kitchener and into the Golden Horseshoe, potentially reaching the Peterborough to Kingston corridor.

At this point, the primary threat should transition to destructive wind gusts, potentially affecting a wide area along the line.

A few QLCS (Quasi-Linear Convective System) tornadoes, which can develop quickly within a squall line, will also be possible. Embedded supercells or isolated supercells immediately ahead of the line could bring an additional tornado threat.

The squall line is expected to continue southeastward while strengthening as it approaches Lake Ontario and Lake Erie before eventually crossing into the United States.

Since the line may strengthen as it tracks southeastward, the Greater Toronto Area, Niagara Region and communities along the northern shoreline of Lake Erie could face the greatest threat. Widespread wind damage will be possible if the line develops as currently expected.

By the middle of the afternoon, between approximately 2 and 3 p.m., Significant Tornado Parameter data shows an increasingly favourable environment for tornado development across the Greater Toronto Area and from areas east of Lake Simcoe through Peterborough.

There is also a conditional threat west of Ottawa if storms can develop behind the cold front after it moves through Algonquin Park, Pembroke and Renfrew. However, storm development in this area is much more uncertain.

A slight tornado risk will also extend farther southwest into Kitchener, London and Chatham. Isolated supercells developing ahead of the squall line could acquire rotation before being overtaken by the main line.

The tornado threat will shift into Niagara Region and the Kingston to Brockville corridor later in the afternoon, generally between 3 and 5 p.m., as the squall line approaches those areas.

The highest severe risk on Saturday is currently focused on the Golden Horseshoe, including Toronto, Hamilton, Mississauga, Kitchener, Guelph, Brantford, Niagara Falls, Newmarket and Oshawa.

We have placed these areas under a “significant” risk, which is level four out of five on our severe weather risk scale.

This risk is primarily driven by the potential for widespread destructive wind gusts accompanying an intense squall line during the early to middle afternoon.

Several tornadoes will also be possible within this region, especially if isolated supercells develop ahead of the main line. Hail up to the size of toonies or Timbits will also be possible.

Flash flooding could become a major concern, particularly throughout heavily urbanized areas. These locations are more vulnerable to significant rainfall over a short period because pavement and other hard surfaces prevent water from quickly soaking into the ground.

A fairly expansive “strong” risk, which is level three out of five, includes Windsor, Chatham, Sarnia, London, Grand Bend, Orangeville, Barrie, Peterborough, Belleville, Kingston and Brockville.

These areas could see one or two tornadoes, along with widespread damaging wind gusts. Large hail up to the size of Timbits will also be possible.

The “widespread” risk, which is level two out of five, covers Grey and Bruce counties, areas east of Georgian Bay, Muskoka, Bancroft, Smiths Falls and Cornwall.

Damaging wind gusts and large hail up to the size of toonies will be possible. An isolated tornado cannot be ruled out, especially east of Georgian Bay through cottage country.

While we have assigned an isolated risk to the Ottawa Valley and Algonquin Park, this is mainly because storm development is more uncertain in these areas. They are also not expected to be directly affected by the intense squall line.

Any severe threat here will likely come from isolated storms developing during the late morning or early afternoon, potentially after the cold front moves through. An isolated tornado will be possible across Algonquin Park and the Ottawa Valley if storms are able to develop.

July 15, 2026

Widespread Evacuations as Northwestern Ontario Wildfires Strain Underfunded Provincial Resources

July 15, 2026/ Brennen Perry

An escalating wildfire emergency is unfolding across Northwestern Ontario, where extreme heat, critically low humidity and strong winds have caused dozens of fires to explode in size, devastated at least one First Nation and forced widespread evacuations.

As of Wednesday, July 15, there were 180 active wildfires across Ontario, with 136 burning in the Northwest Region alone. Dozens remained out of control, while firefighting resources were being prioritized for fires posing the greatest immediate threat to communities, critical infrastructure and public safety.

Crews have been pulled back from some fires because the extreme behaviour has made direct suppression too dangerous. At the same time, the scale of the emergency is renewing questions about whether years of underbudgeting for forest firefighting left the province with less flexibility to position crews, aircraft and equipment before conditions deteriorated.

Ontario budgeted $150 million for Emergency Forest Firefighting this year, despite spending an estimated $271 million last year. A larger initial budget would not necessarily have prevented the current fires or stopped their explosive growth under such extreme weather conditions. However, firefighters have warned that unreliable upfront funding can delay the acquisition and deployment of critical resources when several fires ignite or intensify simultaneously.

Mandatory evacuations are now underway across several First Nations, communities and rural townships in Northwestern Ontario. Other areas, including Ignace, Pickle Lake, Atikokan and Upsala, remain on evacuation standby as conditions continue to evolve.

Beyond the immediate fire zone, enormous smoke plumes have nearly blocked out daylight around Thunder Bay and caused some of the worst air quality Southern Ontario has experienced in years. Smoke has spread into Quebec and the northeastern United States, exposing millions of people to unhealthy and, in some locations, potentially hazardous air.

Nearly 150 Active Fires in Northwestern Ontario

Of the 180 active wildfires reported across Ontario as of Wednesday evening, 136 are burning in the Northwest Region, including 26 new fires that were discovered on Tuesday and 8 more on Wednesday.

As it stands, 63 fires in the Northwest are classified as not under control, five are being held, five are under control, and 63 were being observed. Four fires were declared out during the day.

The number of simultaneous fires has forced officials to prioritize available resources. Fires threatening populated areas, critical infrastructure and evacuation routes are receiving the greatest attention, along with fires where crews have a reasonable chance of safely and successfully slowing their spread.

Some remote fires may be monitored rather than actively suppressed, while personnel and aircraft are directed toward more immediate threats. A fire being observed does not necessarily mean it has been abandoned, as monitoring can be a standard management strategy for remote fires that are not threatening people or infrastructure.

However, with dozens of out-of-control fires and several communities threatened at once, the current situation is placing immense pressure on Ontario’s wildfire response capacity.

How the Wildfire Situation Escalated

Multiple fires were already burning across Northern Ontario during the first week of July, but the situation deteriorated rapidly following a series of lightning strikes produced by thunderstorms that moved across Northwestern Ontario on July 6th and 12th.

A lightning strike does not necessarily cause a tree or surrounding vegetation to immediately erupt into visible flames. An ignition can instead smoulder underground, inside a tree or within dry vegetation for several days before warmer, drier and windier weather allows it to spread.

These are known as holdover fires. They can remain difficult to detect until conditions become favourable enough for them to grow and produce a visible smoke column.

The critical change in conditions arrived on Monday, July 13, when Northwestern Ontario entered a period of extreme heat. Afternoon temperatures climbed into the low to upper 30s while relative humidity fell below 30 percent and winds gusted upwards of 50 km/h.

Wildland firefighters sometimes use the “30-30-30 rule” as a quick indicator of weather capable of supporting extreme fire behaviour. The rule refers to temperatures of at least 30°C, relative humidity of 30 percent or lower and winds of at least 30 km/h. A related warning sign occurs when the temperature rises above the relative humidity value, a situation commonly referred to as crossover conditions.

This combination rapidly dries vegetation, allows flames to spread more quickly and makes direct suppression increasingly difficult and dangerous. Fires can begin crowning through treetops, throwing embers well ahead of the main fire and advancing several kilometres over a short period.

Many parts of Northwestern Ontario reached or exceeded these thresholds beginning Monday. As the extreme heat, low humidity and strong winds have continued on Tuesday and Wednesday, so has the explosive growth of fires across the region.

Not every fire currently burning was caused by the July 6 lightning. Some of the region’s largest fires were detected before then, including Dryden 13 on May 31 and Fort Frances 14 and 15 on June 30. However, holdover fires, along with sparks from the existing fires, may have contributed to the sudden increase in new fire discoveries as conditions have deteriorated over the past few days.

Could Provincial Funding Have Affected the Response?

The scale of the emergency is renewing scrutiny of how Ontario funds its forest firefighting program and whether chronic underbudgeting has limited the province’s ability to prepare proactively for severe fire seasons.

Ontario’s 2026 budget allocates $150 million to Emergency Forest Firefighting. That is $121 million less than the $271 million the province estimates it spent during the 2025-26 fiscal year, representing a reduction of approximately 45 percent compared with last year’s actual spending.

However, the $150-million allocation is $15 million higher than the province originally budgeted for the program last year. The annual budget is also not necessarily a firm spending limit, as additional emergency funding can be approved when wildfire suppression costs exceed the initial allocation.

The broader base budget for the Ministry of Natural Resources is projected to decline from $795 million to $739.5 million, a reduction of $55.5 million. (Ontario’s 2026 Budget)

Experts argue that relying on additional funding after a wildfire emergency has already intensified makes it more difficult to plan and position sufficient resources before multiple fires begin competing for the same crews, helicopters and equipment.

Wildland firefighter and union representative Noah Freedman told the National Observer that insufficient upfront funding can leave the province scrambling to request additional resources after conditions deteriorate.

According to Freedman, logistical problems during the 2025 fire season included a lack of available crews and helicopters in areas where they were needed. He argued that the funding structure can delay resource acquisition and prevent local officials from making proactive decisions before an emergency escalates. (Ontario Association of Fire Chiefs)

Those concerns are particularly relevant during a lightning-driven outbreak. The opportunity to contain a new fire is often greatest while it is still small. If crews or aircraft cannot reach it quickly, a period of hot, dry and windy weather can allow the fire to grow beyond the point where direct suppression is safe or effective.

It is not possible to determine whether a larger initial operating budget would have changed the outcome of any individual fire burning in Northwestern Ontario. The extreme weather experienced this week can produce fire behaviour capable of overwhelming even a well-resourced response.

The decision to withdraw crews from an actively burning area may also be based entirely on immediate safety conditions, rather than staffing or funding. When a fire begins crowning through the treetops, producing long-range embers or advancing rapidly, crews may have no safe option but to retreat.

Still, upfront funding can influence how many crews and aircraft are available, where those resources are positioned and how quickly officials can respond when numerous fires ignite or intensify simultaneously. The current emergency will likely bring further examination of whether Ontario entered the season with enough resources immediately available.

Widespread Evacuations Underway

The rapidly deteriorating conditions have prompted mandatory evacuations across several parts of Northwestern Ontario.

Communities under evacuation orders include Armstrong, Namaygoosisagagun First Nation (Collins First Nation), Gakijiwanong Anishinaabe Nation (Lac La Croix First Nation), Gull Bay First Nation, Lac des Mille Lacs First Nation and Whitesand First Nation.

Evacuation orders are also in effect for the townships of Hutchison, Ramsay Wright, Trottier and Weaver in the Dryden-Fort Frances-Atikokan District.

Cat Lake First Nation, a remote fly-in community surrounded by several fires, was also placed under a mandatory evacuation order Wednesday afternoon.

Fort Hope First Nation, also known as Eabametoong First Nation, and Aroland First Nation have both announced on Wednesday evening that they are evacuating as fires threaten the surrounding area.

Evacuating remote and fly-in communities presents significant logistical challenges. Residents cannot always leave by road, making aircraft availability, safe flying conditions and suitable accommodations in host communities critical parts of the operation.

Authorities have also placed several communities and areas on evacuation standby as the fires continue to spread. These include Ignace, Pickle Lake, Quetico, Crystal Lake, Atikokan, Niobe Lake and Upsala.

Being placed on standby does not mean an evacuation has been ordered. However, residents should prepare to leave quickly if conditions deteriorate. This includes gathering essential medications, identification, important documents, clothing and supplies, along with arranging transportation where necessary.

Residents should closely monitor instructions from local officials and emergency services.

Dryden 13 Devastates Collins First Nation

Dryden 13, also known as DRY013, was first detected on May 31 and has been affecting the Collins, Armstrong and Whitesand First Nation area.

The fire was classified as being held at approximately 14,333 hectares as of June 21. However, the return of hot and dry conditions caused it to grow significantly this week. Its current size remains unclear; however, there are indications that Dryden 13 may have advanced by as much as 50 kilometres on Monday, demonstrating the extreme rate of spread possible under the conditions experienced this week.

The fire advanced rapidly toward Namaygoosisagagun First Nation, also known as Collins First Nation, causing extensive damage and destruction to homes and other buildings. The complete extent of the losses remains unclear, but reports from the community indicate that much, or potentially most, of Collins has been destroyed.

Residents were reportedly forced to flee without the immediate support of emergency services, although all community members had been accounted for based on information available Wednesday morning.

This is near Armstrong, Ontario.

When will the Canadian National Railway Company make a statement about this incident? pic.twitter.com/6bKJYugeR0
— Sol Mamakwa (@solmamakwa) July 14, 2026

Source: Ontario MPP Sol Mamakwa via X

The fire has also burned along the railway corridor near Armstrong. Horrifying video recorded from inside a CN freight train showed flames burning intensely on both sides of the tracks. Thankfully, the train crew was later safely evacuated.

In their Wednesday evening update, the Ministry of Natural Resources has confirmed that Dryden 13, along with several Thunder Bay fires, have merged with the much larger Thunder Bay 36 fire. This fire has been mapped at just over 350,000 hectares in size and is located within Wabakimi Provincial Park.

Fort Frances 14 Threatens Upsala Area

Fort Frances 14, or FOR014, was detected on June 30 and is burning between Highways 11 and 17 in the Upsala and Lac des Mille Lacs area.

The fire reportedly doubled in size overnight from Tuesday into Wednesday. Earlier Wednesday, the Ministry of Natural Resources announced that the fire had been mapped at 18,102 hectares. However, the province’s online fire map later listed its size at 55,106 hectares. It is unclear whether that difference reflects further growth, improved mapping or an adjustment to the estimated perimeter.

Lac des Mille Lacs has lost power as the fire continues to threaten the surrounding area. An emergency meeting was scheduled in Upsala for Wednesday evening, with the possibility of an evacuation expected to be among the issues discussed.

There are also two other fires southwest of Ignace, Dryden 28 and Dryden 36, adding to the increasingly complex situation in the region.

Fort Frances 15 Burns Through Quetico

Fort Frances 15, or FOR015, is burning entirely within Quetico Provincial Park.

The fire was reported at 11,961 hectares earlier Wednesday, but the provincial fire map later listed it at 48,261 hectares. As with Fort Frances 14, it is unclear whether the substantial difference is the result of rapid growth or updated mapping.

Several other fires are also burning within Quetico Provincial Park and along the Highway 11 corridor, including Fort Frances 36 and Fort Frances 38.

Areas of Quetico Provincial Park have been evacuated or closed, affecting backcountry campers and paddlers. The fires are burning in remote terrain where access is limited, further complicating suppression efforts.

The Ministry of Natural Resources has reportedly withdrawn crews from the Ignace and Quetico fires because of extreme fire behaviour. Crews may be repositioned to protect communities and infrastructure or wait for conditions to become safe enough for suppression work to resume.

Minnesota Fires Cross Into Canada

The wildfire emergency extends beyond Ontario, with numerous lightning-caused fires also burning in Northern Minnesota and the Boundary Waters Canoe Area Wilderness.

U.S. fire officials reported that the Bear Trap Fire and Thumb Fire crossed the international border into Canada after exhibiting active or extreme fire behaviour.

The Thumb Fire is burning approximately 10 kilometres south of Gakijiwanong Anishinaabe Nation, also known as Lac La Croix First Nation. Aircraft have continued suppression efforts on the American side while Canadian authorities respond to the portions that have entered Ontario.

The international border has no effect on the spread of a wildfire, making coordination between Ontario and Minnesota authorities critical as fires threaten communities, parks and remote wilderness areas on both sides. (Minnesota Incident Command System)

Highway Closures Complicate Evacuations

Wildfires have affected several major transportation corridors across Northwestern Ontario.

As of 8 PM on July 15th, Highway 599 remains closed between Highway 516 and Mishkeegogamang First Nation, while Highway 527 is closed between Gull Bay First Nation and Armstrong.

Highway 11 was closed between Highways 633 and 623 along the northern edge of Quetico Provincial Park. That section has since reopened, although wildfire crews and emergency equipment may still be operating in the area. Officials continue to ask motorists to avoid non-essential travel.

These closures can significantly complicate evacuations because many Northwestern Ontario communities have few practical alternate routes. They can also disrupt the movement of emergency personnel, firefighting equipment, food, fuel and other critical supplies.

Smoke Spreads Across Eastern North America

The effects of the Northwestern Ontario wildfires are being felt thousands of kilometres away, as enormous quantities of smoke spread across the Great Lakes and into Eastern North America.

#ONStorm #ONwx If you took a look at the Thunder Bay airport camera right now, you’d probably think it was the middle of the night…

Nope. That’s wildfire smoke blocking out the sunlight! 😵‍💫

The smoke has become so thick that it’s dramatically reducing visibility and turning… pic.twitter.com/ThESupj5Ow
— Instant Weather Ontario ⚡️ (@IWeatherON) July 14, 2026

Closer to the fires, smoke has choked portions of Thunder Bay and surrounding areas. At times, it has become thick enough to nearly block out daylight, creating dark and almost apocalyptic scenes during the middle of the day.

The plume began flowing southeastward Tuesday, spreading across the Great Lakes into Southern Ontario, Quebec and the northeastern United States.

Some of the smoke initially remained above ground, but it still affected the weather by limiting the amount of sunlight reaching the surface. This appears to have reduced daytime heating and atmospheric instability, helping suppress what had previously been expected to be a potent severe thunderstorm threat across parts of Eastern Ontario, Quebec and New England on Tuesday.

By late Tuesday, the smoke had begun mixing down to ground level across Southern Ontario. Conditions continued to deteriorate Wednesday as an even thicker plume arrived.

This resulted in some of the worst air quality Southern Ontario has experienced in years. Official Air Quality Health Index readings reached the very high-risk category of 10+ in several communities.

Third-party sensors reported U.S.-scale Air Quality Index values approaching or exceeding 300 to 500 in parts of Southwestern Ontario and the Golden Horseshoe. Values in that range are considered very unhealthy to hazardous.

Toronto was also ranked as having some of the worst air quality among major cities worldwide Wednesday as smoke blanketed the region. (Ontario Air Quality Health Index)

The worst conditions across Southern Ontario are expected to peak between late Wednesday and Thursday afternoon. Some smoke will likely linger into Friday and potentially the weekend, although its intensity and duration will depend heavily on fire behaviour and wind patterns over the next 24 to 48 hours.

Staying Safe During Hazardous Air Quality

Wildfire smoke contains fine particulate matter known as PM2.5. These particles are small enough to travel deep into the lungs and enter the bloodstream, potentially aggravating asthma, heart disease and other respiratory or cardiovascular conditions.

Children, older adults, pregnant people, those with heart or lung conditions and anyone working or exercising outdoors face an increased risk. However, smoke this intense can cause symptoms even in otherwise healthy people.

Residents should reduce or postpone strenuous outdoor activity and spend as much time as possible in a location with cleaner, filtered air. Keep windows and doors closed where it is safe to do so, set central air systems to recirculate and use the highest-quality filter the system can safely accommodate. A portable air purifier with a HEPA filter can also help reduce smoke particles indoors.

However, anyone without air conditioning should not allow their home to become dangerously hot simply to keep smoke outside. If indoor temperatures become unsafe, consider visiting a public cooling centre, library, shopping centre or another air-conditioned location with cleaner air.

Anyone who must go outside should consider wearing a properly fitted N95, KN95 or KF94 mask. Cloth and loose-fitting surgical masks provide little protection against the fine particles in wildfire smoke.

Watch for symptoms including coughing, wheezing, headaches, dizziness, eye or throat irritation, shortness of breath and chest discomfort. Anyone experiencing severe difficulty breathing, chest pain or another medical emergency should seek immediate medical assistance. (Health Canada wildfire smoke guidance)

With extreme fire behaviour continuing across Northwestern Ontario, the full extent of the emergency may not be known for some time.

Fire sizes can change dramatically when officials receive new satellite data or more accurate aerial mapping. This may explain some of the substantial differences between fire sizes announced earlier Wednesday and those later displayed on the provincial fire map.

Weather conditions over the next several days will play a major role in determining whether crews can regain control. Cooler temperatures, higher humidity and lighter winds would help reduce fire behaviour, but meaningful rainfall may be needed to provide more substantial relief.

Fire sizes, classifications, road closures, air quality conditions and evacuation orders may change rapidly. Residents in affected areas should continue following instructions from local officials and emergency services.

July 14, 2026

Edmonton Area in the Crosshairs for Strong Severe Thunderstorms Tuesday with Threat of Very Large Hail and Possible Tornadoes

July 14, 2026/ Alannah Campbell

It’ll be yet another day with the threat of strong severe thunderstorms for parts of Alberta. Today’s risk will be along the Highway 43 corridor between Whitecourt and Edmonton, and throughout the surrounding area, including Edson, Drayton Valley, and Westlock.

There will be plenty of instability in the atmosphere across Central Alberta and into parts of Northern Alberta today, with upwards of 3000J/kg of CAPE being shown on weather models beginning this afternoon. Additionally, ample moisture and shear throughout the region will lead to all the necessary ingredients being in place for some strong severe thunderstorms to develop.

Today’s thunderstorms could possibly begin in the Foothills in the mid-to-late afternoon, but it’s more likely that storms will fire up in this area during the early evening. Once the isolated storms do start to develop, they are expected to rapidly strengthen into strong supercells, which will track mostly eastward across the province through the remainder of the evening and overnight.

***Hourly Precipitation at 1Am MDT, courtesy of weatherbell.***

These severe thunderstorms are expected to reach the Edmonton area sometime in the late evening or shortly after midnight, around 11pm-2am. These thunderstorms could very likely maintain their strength up until this point, however there is also the possibility that the storms will weaken to the west, before hitting Edmonton. Regardless, as we progress overnight and into the pre-dawn hours, and the storms continue tracking eastwards, they are expected to weaken considerably and will likely dissipate before reaching the Saskatchewan border.

The greatest threat from the strong supercell thunderstorms today will be very large hail, which could end up being up to tennis ball size. There will also be the risk of damaging wind gusts in excess of 100km/h, intense rainfall, and even the possibility of a tornado or two.

In the meantime, there will be a more isolated severe risk this afternoon and evening in Southeastern Alberta. The storms in this part of the province aren’t expected to be particularly strong, especially when compared to the storms further north, with the main concern being some strong wind gusts, small hail, and pockets of heavy rain.

Given that today’s strong severe thunderstorms will have tornado potential continuing after dark, especially in such a populated area, it’s crucial to ensure that you have all of your devices charged and that you have more than one way to receive critical alerts. We expect to be live-streaming today’s storms once they begin to develop, along with those in Ontario, Quebec, and New Brunswick, so be sure to tune in!

July 14, 2026

Potential Record-Breaking Heat to Fuel Severe Thunderstorm Threat Across Southern Ontario Tuesday

July 14, 2026/ Brennen Perry

Dangerously hot temperatures are returning to Southern Ontario, bringing another multi-day heat wave to the region. This heat wave is expected to peak on Tuesday, when temperatures could climb into the mid to upper 30s across many communities.

As temperatures rise, so does the instability in the atmosphere, and Tuesday will be no exception. The intense heat will help fuel the potential for strong to severe thunderstorms across parts of Southern Ontario.

The greatest severe weather threat is expected to focus on the Ottawa Valley, where a cold front will move through the hot, humid air during the late afternoon and early evening. As the front arrives, it is expected to spark a line of thunderstorms capable of quickly becoming severe.

The environment appears favourable for some of these storms to develop into supercells capable of producing all severe weather hazards, including destructive wind gusts, golf ball-sized hail and a few tornadoes.

Elsewhere across Southern Ontario, widespread thunderstorm development is not expected as there is no well-defined trigger in place. However, isolated storms could still develop along lake breeze boundaries or from outflow boundaries generated by other storms. With plenty of instability available, any storm that manages to form could become severe. Most communities, however, are expected to remain dry on Tuesday.

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Another developing story that could have significant implications for Southern Ontario’s weather is the rapid increase in wildfire activity across Northwestern Ontario. A large number of new wildfires ignited over the past day, and the smoke from these fires is expected to begin spreading into Southern Ontario as early as Tuesday. An even more significant plume is expected to arrive on Wednesday.

In addition to air quality concerns, this smoke could also influence thunderstorm development on Tuesday by limiting the amount of sunshine reaching the surface. If enough smoke is present, it could reduce instability and lead to fewer storms than currently expected.

Tuesday is shaping up to be a sweltering day, with temperatures climbing above 35°C across a large portion of Southern Ontario and potentially approaching the 40°C mark in a few locations. That’s before factoring in the humidity, which could make it feel more like the mid to upper 40s.

The hottest conditions are expected in a corridor stretching from Deep Southwestern Ontario through the Golden Horseshoe and into the Ottawa Valley. Afternoon highs here will likely range between 36 and 38°C, with parts of the Greater Toronto Area potentially reaching 39 to 40°C.

One reason the Greater Toronto Area could end up even hotter than surrounding communities is because of the urban heat island effect. Cities are filled with concrete, asphalt and buildings that absorb heat from the sun throughout the day and slowly release it back into the surrounding air. With fewer trees and green spaces to provide cooling, temperatures in urban areas can end up several degrees warmer than nearby rural locations, especially during prolonged heat waves.

The remainder of Southern Ontario can expect highs ranging from 30 to 36°C. Communities located directly along the northeastern shores of Lake Erie and Lake Ontario, as well as the eastern shores of Lake Huron and Georgian Bay, could be 5 to 10°C cooler thanks to cooling lake breezes.

Humidity is not expected to be quite as intense as it was during the late June heat wave, when humidex values approached 50°C in some areas. Even so, it will still make conditions feel like the low to mid 40s, with a few locations around the Golden Horseshoe potentially approaching the upper 40s.

These temperatures can become dangerous very quickly, especially for older adults, young children, people with chronic health conditions and anyone spending extended periods outdoors. Stay well hydrated, avoid strenuous outdoor activities during the hottest part of the day, wear lightweight clothing and seek air-conditioned spaces whenever possible.

Never leave children or pets inside a parked vehicle, even for a few minutes, as temperatures inside can rise to life-threatening levels in a very short amount of time!

The hot, dry weather has also created ideal conditions for wildfire growth across Northwestern Ontario, and we’ve seen exactly that over the past 12 hours.

More than a dozen new wildfires have ignited, with many of them concentrated northwest of Thunder Bay. A southeasterly wind flow is expected to carry smoke from these fires into Southern Ontario over the next several days.

Initially, much of this smoke should remain high in the atmosphere. However, by Wednesday we could be dealing with a significant wildfire smoke event across Southern Ontario as more of the smoke mixes down to the surface, potentially leading to hazardous air quality. More details on that once models start ingesting the data from the new fire.

Even Tuesday’s elevated smoke could influence our weather, particularly across Central and Eastern Ontario. We’ve seen in the past that thicker smoke can reduce the amount of sunlight reaching the ground, limiting daytime heating and making it more difficult for thunderstorms to develop.

As a result, there is a real possibility that Tuesday’s severe weather threat could underperform if the smoke becomes thick enough to suppress storm development.

Assuming the smoke does not significantly interfere, the latest model data shows a line of thunderstorms developing around the dinner hour from North Bay to just north of Ottawa.

The exact timing will depend on when the cold front arrives, but the primary threat window currently appears to be between 4 PM and 10 PM.

These storms are then expected to track southeast through the Ottawa Valley, potentially affecting portions of Central Ontario before continuing into southeastern Quebec and eventually crossing into the northeastern United States.

We could also see isolated thunderstorms develop during the afternoon and early evening across other parts of Southern Ontario. These would likely be triggered by lake breeze boundaries or other localized features that weather models often struggle to resolve.

Any storm that is able to develop could quickly become severe, producing damaging wind gusts and large hail. The greatest tornado threat remains focused across Eastern Ontario.

Based on the expected environment, we’re forecasting a “Strong” (Level 3 of 5) severe weather risk for Ottawa, Cornwall, Smiths Falls, Renfrew, Pembroke and Deep River. This reflects the potential for widespread damaging wind gusts, golf ball-sized hail, one or two tornadoes and localized flash flooding.

A “Widespread” (Level 2 of 5) severe weather risk extends across the rest of Eastern and portions of Central Ontario, including Brockville, Bancroft, Huntsville, Algonquin Park, Sundridge and North Bay. Confidence is a bit lower than across the Ottawa Valley, but several severe storms remain possible with damaging wind gusts, Timbit-sized hail and an isolated tornado.

The remainder of Southern Ontario is under an “Isolated” (Level 1 of 5) severe weather risk. Most communities in this area will likely remain storm-free. However, if a thunderstorm is able to develop along a lake breeze or another localized boundary, it could produce isolated damaging wind gusts and up to quarter-sized hail.

July 11, 2026

Widespread Tornado and Large Hail Threat with Another Risk of Severe Thunderstorms in Alberta & Saskatchewan Saturday

July 11, 2026/ Alannah Campbell

Following yesterday's widespread severe weather, in which multiple tornadoes were reported to have touched down in Central Saskatchewan, as well as one possibly touching down to the west of Edmonton, we're in for yet another day with the risk for strong severe thunderstorms.

For several days, weather models have been showing that the environment could be extremely unstable today, especially across much of Saskatchewan, which could result in a fairly significant severe weather outbreak. Working against this, however, is the likelihood that there could actually be too heat higher up in the atmosphere, which could create a strong capping inversion that would hinder thunderstorm development. This is expected to be the case for much of Southern Saskatchewan today, where there will be a more isolated severe risk. It's important to note that any storms that are able to develop in this region will probably be quite strong.

Shifting northward, the capping should be less of an issue in Central and Northern parts of Alberta and Saskatchewan. Across this large swath of the Prairies, severe thunderstorms are expected to develop much more readily in a favourable environment.

Although there are already some thunderstorms this morning in Central and Northern Alberta, the storms that we are most concerned about are expected to beginning developing early this afternoon in Western Alberta, which will track mostly eastward through the afternoon.

As these storms cross into Saskatchewan early this evening, they could strengthen considerably as they move through the most ideal environment. These thunderstorms are expected to maintain their strength as they cross Saskatchewan during the evening and into the overnight hours. As they approach the provincial border and cross into Western Manitoba, the storms are expected to weaken and then dissipate in the early morning hours.

At their strongest, the severe thunderstorms today could easily produce large golf ball to tennis ball size hail, damaging wind gusts up to and possibly exceeding 100km/h, and heavy rain. There will be a widespread risk of tornadoes today in the area outlined in yellow and even in Southern Saskatchewan if storms are able to form there, but the most significant risk will be in the orange region. An area of particular concern today will be around North Battleford, Saskatoon, and Prince Alberta.

This is looking like it could be another long day with a heightened severe weather threat across the Prairies. Given today’s widespread tornado risk, please ensure that you have all of your devices charged and that you have more than one way to receive critical alerts. We expect to be livestreaming today’s storms so be sure to tune in!

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Nearly 150 Active Fires in Northwestern Ontario

How the Wildfire Situation Escalated

Could Provincial Funding Have Affected the Response?

Widespread Evacuations Underway

Dryden 13 Devastates Collins First Nation

Fort Frances 14 Threatens Upsala Area

Fort Frances 15 Burns Through Quetico

Minnesota Fires Cross Into Canada

Highway Closures Complicate Evacuations

Smoke Spreads Across Eastern North America

Staying Safe During Hazardous Air Quality

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