Southern Ontario to Kick Off Summer This Weekend With Significant Severe Risk and Tornado Threat on Saturday; Sizzling Heat Near 40°C on Sunday

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Summer officially arrived late Friday night with the summer solstice, and it looks like Mother Nature isn’t wasting any time making it feel like summer across Southern Ontario. A multi-day heat wave is on the way, bringing the potential for record-breaking temperatures starting Sunday and continuing into early next week.

But before the heat sets in, we’re looking at what could easily be our strongest and most widespread severe weather threat of the season so far on Saturday. There are a lot of factors at play that make this a classic ‘boom or bust’ setup, which we’ll break down below.

There’s high confidence in a potent storm environment stretching across much of Southern Ontario. The big wildcard, however, is whether storms will actually develop to take advantage of all that energy. If they do, they could bring very large hail, destructive wind gusts, and possibly even a couple of tornadoes.

What’s especially concerning is that the storm environment doesn’t fade away after sunset like it typically does. In fact, it remains quite strong through the overnight and into Sunday morning, which could support a nocturnal line of storms with widespread damaging wind potential.

Once the severe risk passes, intense heat begins to build. Temperatures will soar well into the 30s by Sunday, with humidex values making it feel closer to the 40s. The heat continues Monday and Tuesday, with some relief expected midweek. That said, it’ll likely stay warm into the end of June and possibly early July.

A key ingredient in Saturday’s severe weather threat is already unfolding over North Dakota early Saturday morning. An intense line of storms, known as a “derecho” (a fast-moving complex of severe thunderstorms that can produce widespread wind damage), is sweeping through the northern Plains.

This system is producing destructive wind gusts of over 150 km/h along with several tornadoes and has already left damage in its wake. It’s expected to continue tracking eastward into the Great Lakes region through the day.

SIMULATED RADAR - MAP FROM WEATHERBELL

So what does that mean for Southern Ontario?

Derechos are known to travel long distances, and current model guidance suggests this one could follow a path toward Northeastern Ontario. Areas near the U.S. border, including Sault Ste. Marie and Elliot Lake, could be affected by the remnants of this system Sunday morning.

There’s still some uncertainty around how strong the system will be by the time it reaches Ontario. Forecast models often struggle with capturing the evolution and intensity of derechos, so the possibility that this one is being underestimated shouldn’t be ignored.

SIMULATED RADAR - MAP FROM WEATHERBELL

The projected track of what’s left of this potentially decaying derecho places it crossing Lake Huron and Georgian Bay into Central Ontario sometime Saturday afternoon.

If it maintains strength, it could bring damaging wind gusts, hail up to the size of toonies and maybe even an isolated tornado. But this could just be the first of multiple storm rounds.

Some models are also hinting at additional isolated storm development around Elliot Lake and Sudbury in the wake of the earlier line. That suggests the atmosphere could quickly recharge, although it’s still unclear how widespread any new storms would be.

ESTIMATED ENVIRONMENT FOR TORNADOES - MAP FROM WEATHERBELL

As we move into the late afternoon and evening hours on Saturday, the storm environment really ramps up. One of the key indicators we look at, the Significant Tornado Parameter, is literally off the charts in some areas, particularly near the Lake Huron shoreline and into Georgian Bay.

Here’s the catch, though: storms need to develop in this environment to take advantage of it. If they do, they could rapidly become severe, with the potential for all hazards. That includes large hail (possibly golf ball-sized or bigger), destructive winds over 100 km/h, and tornadoes.

SIMULATED RADAR - MAP FROM WEATHERBELL

Looking at what one model is simulating, there’s a notable lack of storms in the highest risk areas around Lake Huron. Instead, storms appear to fire up along a line from Sudbury to Parry Sound through Muskoka, just northeast of the most primed environment. These storms could still be strong and bring similar hazards.

It’s worth noting that models may be underdoing storm development in Southwestern Ontario. That’s something we’ll need to monitor in real time. If nothing happens in Southwestern Ontario, it could end up being a ‘bust’ - which would be good news for those who aren’t fans of severe storms.

ESTIMATED ENVIRONMENT FOR TORNADOES - MAP FROM WEATHERBELL

Typically, severe weather threats wind down after sunset as daytime heating fades. But in this case, models are suggesting the environment will remain unusually supportive of storm activity well into the overnight hours and early Sunday.

There’s even the potential that a new line of storms forms north of Georgian Bay and sweeps southeast through Southern Ontario overnight. If this happens, it could evolve into another derecho-type system - similar to the one seen Friday night in North Dakota.

Forecasting derechos is notoriously difficult, as models often fail to capture their full strength and endurance. While nothing is certain, this setup definitely has the ingredients to support a nocturnal derecho-type event.

If this scenario plays out, we could see widespread wind damage across Central and Eastern Ontario, possibly extending into parts of Southwestern Ontario and the Golden Horseshoe.

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This is a very tricky forecast, and while we've gone with a ‘significant’ (level 4 out of 5) risk, that doesn’t mean everyone will see storms. The risk will come in waves, and some areas may be completely missed.

That said, the potential severity of any storms that do form justifies this level of concern. We’re talking about the possibility of golf ball-sized hail or larger, destructive wind gusts (possibly from a derecho), and a few tornadoes. The tornado risk will largely depend on storm structure—more linear setups will favour damaging wind, while discrete supercells could increase the tornado threat.

The highest severe risk covers areas around Georgian Bay including Sault Ste. Marie, Elliot Lake, Manitoulin Island, Britt, and into Central Ontario such as Muskoka, Simcoe County and Bancroft.

A broader ‘strong’ risk zone includes much of Central and Eastern Ontario, the northern portions of Southwestern Ontario, and the Greater Toronto Area.

Meanwhile, areas like London, Kitchener, Hamilton and the Niagara region fall into the widespread severe risk category.

For once, Deep Southwestern Ontario may dodge the worst of the storms. Windsor, Chatham and Sarnia are currently in the isolated severe risk zone. While a stray storm can’t be ruled out, most of that region looks to stay quiet Saturday.

There may be another round of severe weather on Sunday afternoon and evening, but confidence in the details is still low. Eastern Ontario may be favoured, but we’ll refine that forecast once Saturday plays out.

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Sunday marks the beginning of an extended stretch of dangerously hot temperatures. The most intense heat is expected across Deep Southwestern Ontario into the Golden Horseshoe.

Areas like Windsor, Sarnia, London, Hamilton, Kitchener and Toronto could see daytime highs between 35°C and 40°C. With humidity, it will feel like the mid-40s in many spots.

Locations near Lake Ontario, Lake Erie, Lake Huron and Georgian Bay will be 5 to 10 degrees cooler, but it doesn’t take much distance inland to hit the oppressive heat.

Elsewhere in Southern Ontario, expect highs in the low to mid-30s with humidex values near 40°C.

Heat Safety Tips:

  • Stay hydrated and avoid strenuous outdoor activity during peak heat hours.

  • Check in on vulnerable individuals, including the elderly, young children and those with health conditions.

  • Never leave pets or people in parked vehicles.

  • Use fans or air conditioning when possible and find shade or cooling centres if needed.

SOURCE: ECCC

There’s a good chance many locations will break temperature records going as far back as the 1800s over the next few days.

According to Environment Canada, record highs in cities like Toronto, Windsor, Ottawa, London and Hamilton are in the mid to upper 30s for Sunday, Monday and Tuesday. Based on the current forecast, some of these records may fall.

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Monday brings more of the same, with extreme heat expanding into parts of Central and Eastern Ontario in addition to Southwestern Ontario and the GTA.

Once again, humidex values will push into the 40s, making it feel extremely uncomfortable and even dangerous for some.

Tuesday will still be hot, but may be slightly cooler compared to Monday. Some relief is on the way by Wednesday, although temperatures will likely stay warm overall.

Severe Storms Target Southwestern Ontario Wednesday with Tornado and Damaging Wind Risk

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Storm season has certainly gotten off to a slow start in Southern Ontario, to say the least. Aside from a few scattered events earlier in the spring, it’s been a fairly quiet lead-up to summer across the region.

However, that’s about to change in a big way. As we approach the summer solstice on Friday, which marks the official start of summer, the pattern is shifting. Warmer temperatures and a more active storm pattern are setting the stage for what looks like a much stormier stretch of weather.

Wednesday’s setup will feature an environment that becomes increasingly favourable for storm development through the day. The main focus will be across Southwestern Ontario and into parts of the Golden Horseshoe during the afternoon and evening hours.

While the storms will likely start off isolated and scattered, they are likely to move quite slowly. This raises the potential for localized flooding, especially in areas that see multiple rounds of heavy rainfall from training storms.

A few storms could also produce near-severe wind gusts and small hail, particularly during the late afternoon and early evening. While not every area will be affected, those that are could see some very heavy rainfall over a short period of time.

The greater concern comes later in the day for Deep Southwestern Ontario, where a more potent setup could take shape.

Storms are expected to develop over Michigan during the afternoon and early evening. As these storms intensify, they may track eastward and cross into Ontario during the evening. Areas such as Windsor, Chatham, and Sarnia could be in the path of these stronger cells.

These storms will be moving into a more unstable environment that could support damaging wind gusts, quarter-sized hail, and potentially even an isolated tornado.

While confidence in storm development across the border is high, the extent of the severe threat in Ontario will depend heavily on the exact timing of when those storms cross into the province.

ESTIMATED AIR TEMPERATURE - MAP FROM WEATHERBELL

Before the storms arrive, temperatures will be on the rise across much of Southern Ontario. Afternoon highs are expected to reach the mid to upper 20s across Southwestern Ontario and into the Golden Horseshoe by early afternoon.

Central and Eastern Ontario will be a bit cooler, with highs ranging from the low to mid-20s. The Ottawa Valley could end up a touch warmer than the surrounding areas.

SIMULATED RADAR - MAP FROM WEATHERBELL

This heat and humidity will act as fuel for thunderstorm development, especially around Lake Huron and into areas near Lake Simcoe by the afternoon. Models vary on how widespread storm activity will be, with some showing scattered pop-up storms and others hinting at a more organized cluster.

Either way, any storms that do develop will be slow-moving, and locations underneath these cells could see multiple rounds of rainfall. That’s where the flood threat becomes more concerning, especially in urban areas that are more prone to flash flooding.

For much of the region, flooding will remain the primary concern. However, a few stronger storms could bring near-severe wind gusts and hail up to nickel size.

SIMULATED RADAR - MAP FROM WEATHERBELL

By the evening, our attention will turn stateside, where strong to severe storms are expected to organize over Michigan.

These storms are forecast to cross into Deep Southwestern Ontario sometime during the evening. The atmospheric setup in that region will support damaging wind gusts, hail up to the size of quarters, and the potential for a tornado.

Again, the timing will be critical. If these storms arrive before sunset, they’ll have access to better instability and surface heating, making them more capable of becoming severe. However, if they hold off until later in the night, the lack of daylight heating could limit their intensity.

ESTIMATED ENVIRONMENT FOR TORNADOES - MAP FROM WEATHERBELL

Models are currently showing a narrow window between 6 and 9 PM where the tornado potential could materialize, particularly around Windsor, Leamington, and Chatham. This will depend on how quickly storms move eastward from Michigan and whether they interact with the more favourable environment before it begins to weaken.

Once the sun sets, the tornado threat should diminish quickly, though some thunderstorm activity may continue through the night into early Thursday morning.

While a few non-severe thunderstorms may linger overnight, the severe threat will likely taper off before midnight.

As it stands, the highest risk for severe weather on Wednesday will be focused on Deep Southwestern Ontario, including Windsor, Leamington, Chatham, and Sarnia, with the window for impactful storms likely between 3 PM and midnight.

We’ve placed this region under a Level 2 (Widespread) risk due to the potential for damaging wind gusts and one or two tornadoes. Up to quarter-sized hail and locally up ot 50-100mm of rain is also possible.

Elsewhere across Southwestern Ontario and into the Golden Horseshoe, we’ve gone with a Level 1 (Isolated) risk.

This lower tier is mainly for flooding concerns, as slow-moving storms could drop significant rainfall over the same areas during the afternoon and early evening.

Some locations could also see isolated severe wind gusts, nickel-sized hail, and a very low tornado risk (confined mainly to parts of Southwestern Ontario).

Two EF1 Tornadoes Confirmed Northeast of Edmonton From Monday, May 26th, 2025

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Two EF1 tornadoes have been confirmed in Alberta from May 26th, 2025 by the Northern Tornadoes Project (NTP). Thankfully, there were no injuries with these two tornadoes. The strongest of the two was on the ground for an impressive 21.2km and had estimated wind speeds of 175km/h. The two tornadoes touched down near Lac la Biche and left behind lengthy, narrow paths of damage, including a partially removed roof from a home and numerous snapped and uprooted trees.

Investigators from the NTP conducted thorough ground and drone surveys on May 28th and noted that Alannah and Patricia from our own Instant Weather team helped get their team deployed quickly. The NTP wrote: “Thanks to Alannah and Patricia at Instant Weather for their initial (late-night) alert to the damage, allowing us to get our team out faster!” We at IW are grateful that we were able to help NTP with their investigation and super thankful that no one was injured in these two tornadoes. The NTP meticulously documented the aftermath and their findings paint a clear picture of the two separate twisters that tore through the region.

The Atmore Twister – A Lengthy Path of Damage

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The first tornado, designated the "Atmore" event, began its destructive journey at approximately 7:00 PM MDT (0100 UTC) on May 26th.

Final EF-Scale Rating: EF1

Estimated Max. Wind Speed: 175 km/h

Track Length: A substantial 21.2 km

Max. Path Width: 300 m

Motion: From the Southwest (approx. 220 degrees)

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This twister carved a significant path, causing notable damage to homes near Atmore and Rossian (north of Plamondon). Reports detailed structural impacts and the NTP survey confirmed these, along with extensive tree damage. Satellite imagery review also highlighted the visible tree damage along its long, narrow track. Luckily, despite the substantial property damage, no injuries were reported.

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The Avenir Tornado – A Shorter, Wider Impact

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Just 25 minutes after the Atmore tornado began, a second EF1, named the "Avenir" event, touched down further to the northeast at approximately 7:25 PM MDT (0125 UTC).

  • Final EF-Scale Rating: EF1

  • Estimated Max. Wind Speed: 150 km/h

  • Track Length: 6.43 km

  • Max. Path Width: A slightly wider 370 m

  • Motion: From the South-Southwest (approx. 205 degrees)

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While shorter in track length, the Avenir tornado left a clear signature, primarily impacting forested areas near the community of Avenir. Satellite imagery initially revealed its narrow path of tree damage, which was later confirmed and documented by the NTP's ground and drone survey. As with the Atmore event, no injuries were reported in connection with this tornado.

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Understanding the Findings

The Northern Tornadoes Project plays a crucial role in confirming, classifying and analyzing tornado damage across Canada. Their use of satellite imagery, followed by on-the-ground surveys with drones, allows for precise classification and understanding of these powerful weather phenomena.

These EF1 tornadoes, with wind speeds reaching up to 175 km/h, serve as a reminder of the potential for severe weather in Alberta. While not the most powerful on the Enhanced Fujita (EF) Scale, they are certainly capable of causing significant localized damage, as evidenced by the events near Lac la Biche.

Find out more & get notified

  • You can view precise tracks of these tornadoes and explore other Canadian tornado and downburst events on the interactive NTP Dashboard.

  • Always have a plan for severe weather and download our free app Instant Weather to get notified of any alerts from Environment Canada or any custom updates from the IW team regarding rotation, funnel cloud reports, etc.

Ontario’s First Confirmed Tornado of 2025: EF0 Touches Down Near Woodstock Last Week

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Ontario’s tornado season has officially begun. The first confirmed tornado of 2025 touched down during the early morning hours of May 16th, just south of Lakeside, Ontario, northwest of Woodstock.

The tornado developed along the leading edge of a line of storms that had tracked into the province from Michigan.

While this EF0 tornado near Lakeside was the first confirmed in Ontario this year, it wasn’t the first in Canada.

According to the Northern Tornadoes Project, this brings Canada’s confirmed tornado count for 2025 to five.

The season began with an EF0 tornado in Alberta in early April, followed by an EF1 in Quebec later that month. Just one day before the Lakeside event, two EF0 tornadoes were confirmed in Manitoba on May 15th.

With peak season still ahead, this serves as a timely reminder that severe weather can happen quickly and under conditions that don’t always look extreme on the surface.

Even low-end risks deserve attention, especially when storms arrive at night, when people are less likely to be tuned in.

The Tornado: A Narrow but Confirmed Touchdown Near Lakeside

Survey map for the Lakeside EF0 tornado (source: Northern Tornadoes Project)

According to the Northern Tornadoes Project (NTP), the tornado developed just south of the village of Lakeside, approximately 25 km northwest of Woodstock. It touched down around 3:00 AM EDT, shortly after a squall line of thunderstorms entered the region from the west.

Drone photo of worst damage point featuring multiple snapped conifers (source: Northern Tornadoes Project)

Damage was limited to trees and a power pole, with no injuries reported. The tornado was assessed as an EF0, with estimated maximum wind speeds of 115 km/h. It travelled a distance of 3.6 km, with a maximum path width of 160 metres, moving generally from the west-southwest (255°).

Radar data shows possible rotation near lakeside (source: iw pro)

Radar imagery at the time showed a compact area of low-level rotation, but due to the storm’s embedded structure and the overnight timing, the event went unwitnessed until damage was reported later that day.

The NTP conducted both ground and drone surveys on May 20th to confirm the tornado’s track and intensity.

This information is sourced from the Northern Tornadoes Project’s full report, which can be found here.

Survey map showing the location of the EF0 downburst (black oval) and collected data (source: Northern Tornadoes Project)

In addition to the confirmed tornado near Lakeside, the Northern Tornadoes Project also verified a separate EF0 downburst near Chatham from the same storm system.

The downburst occurred around 2:15 AM EDT, roughly 45 minutes before the tornado, and caused significant damage to several barns, farm buildings, power poles, and trees.

While similar wind damage was reported across parts of Southwestern Ontario—from Windsor to Shrewsbury—only the enhanced damage south of Chatham was surveyed.

Wind speeds were estimated to have peaked at 130 km/h, placing the event at the high end of the EF0 scale. No injuries were reported.

Timeline: Forecast Leading Up to the Tornado

Forecast models began flagging the potential for severe storms several days in advance, particularly in Deep Southwestern Ontario, where the environment appeared favourable for severe weather.

Instant Weather and the U.S. Storm Prediction Center both noted the possibility of tornadoes — albeit marginal — due to the timing and nocturnal nature of the storms. This provided over 24 hours of advance notice about the potential for severe weather.

Despite the lower-end risk, one storm managed to spin up a brief EF0 tornado shortly after 3:00 AM on May 16th.

Instant Weather first highlighted the tornado potential on Wednesday afternoon, referencing the Storm Prediction Center’s forecast and the setup in Michigan and Southwestern Ontario:

The following morning, just under 24 hours before the confirmed tornado, Instant Weather once again flagged the risk.

This time, the post specifically mentioned that a 2% tornado risk extended into Sarnia, Chatham, Grand Bend, and as far northeast as London, placing the affected area firmly within the broader risk zone:

Later Thursday afternoon, a forecast was issued by Instant Weather calling for the potential of isolated tornadoes overnight. The forecast map outlined a marginal risk that included the area near Lakeside, where the tornado would eventually touch down:

Around 1:47 AM, just over an hour before the tornado touched down, Instant Weather sent out a custom notification for the London area, referencing minor rotation and clearly stating that “an isolated tornado cannot be ruled out”:

At 2:55 AM, Environment Canada issued a Severe Thunderstorm Warning, which included a note that severe thunderstorms can produce tornadoes. This came approximately five minutes before the tornado would touch down near Lakeside

Finally, live coverage was underway on Instant Weather’s YouTube channel during the time the tornado developed around 3:00 AM, as the storm moved through Oxford County.

Nocturnal Thunderstorm Threat With Damaging Wind Gusts and Isolated Tornado Risk for Southwestern Ontario Tonight

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updated map - 10:50 PM (CLICK HERE FOR THE PREVIOUS MAP)

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UPDATE (10:50 PM):

We’ve been closely tracking the line of storms developing across Michigan, and it’s now set to move into Deep Southwestern Ontario over the next few hours.

Based on the latest model data, current environmental conditions, and how well the storm is holding together despite the lack of daylight heating, we believe there’s enough evidence to upgrade parts of Deep Southwestern Ontario to a ‘strong’ (3/5) risk—mainly due to the potential for intense wind gusts.

Large hail up to the size of toonies is also possible, and we can’t completely rule out an isolated tornado.

We’ve also extended the ‘slight’ (2/5) risk further inland to include areas like Goderich and London, as new data suggests the line could stay fairly strong as it tracks deeper into Southwestern Ontario during the pre-dawn hours. Again, damaging wind gusts remain the primary threat.

The line is expected to cross the border just after midnight, with the severe threat gradually tapering off but still continuing until around 3–4 AM.

ORIGINAL FORECAST

While storm season has had a quiet start in Southern Ontario, things are beginning to ramp up with a late-night storm risk expected between Thursday evening and early Friday morning. A strong line of storms is forecast to form across Michigan late tonight, initially beginning as discrete supercells over parts of Wisconsin and Illinois.

Based on the latest guidance, these storms are expected to organize into a more linear structure as they track eastward, eventually crossing into Southwestern Ontario sometime just after midnight. While they’ll likely lose some of their strength after dark, especially without daytime heating, the atmosphere may still be supportive enough for them to maintain some intensity as they move into our region.

That said, there’s still a fair amount of uncertainty about just how strong this line will be once it crosses the border, and how quickly it might weaken as it tracks northeast through the early morning hours of Friday.

The biggest concern with this system is the potential for damaging wind gusts. This squall line will stretch from the Upper Peninsula of Michigan all the way down through Ohio as it enters Ontario, which could lead to widespread impacts. Areas from the Bruce Peninsula all the way down to Deep Southwestern Ontario are at risk of strong winds embedded within the line.

The highest risk appears to be in Deep Southwestern Ontario, where the line will first cross into Ontario. Regions like Windsor, Leamington, Chatham, and Sarnia are most likely to experience the strongest part of this line. While damaging wind gusts are the main hazard, we also can’t completely rule out the chance for hail and even a brief tornado, especially if the storms arrive a bit earlier than forecast.

Hail up to the size of quarters is possible, and while the tornado risk is considered low overall, it does exist. The biggest concern here is that this is a nocturnal threat. If a tornado were to develop overnight, it would be harder to spot and could be rain-wrapped, making it even more dangerous. That’s why it’s so important to stay alert and have a way to receive warnings while you sleep.

SIMULATED RADAR - MAP FROM WEATHERBELL

Storm development will begin with discrete cells over Wisconsin and Illinois, likely forming into a long line around 8–10 PM near Chicago and across Lake Michigan.

The timing of this formation is crucial. If the line develops sooner and sweeps across Michigan quickly, it could result in a more robust severe risk for Deep Southwestern Ontario, where the environment is more favourable before midnight.

No matter the timing, damaging winds remain the most likely outcome with this type of linear storm setup.

SIMULATED RADAR - MAP FROM WEATHERBELL

As of now, future radar models suggest the storms will cross into Ontario between 1 and 2 AM, hitting areas like Windsor and Sarnia first before stretching further northeast. However, there’s still wiggle room in this timing. It could arrive earlier and stronger, or later and already weakening before reaching our region.

ESTIMATED TORNADO ENVIRONMENT - MAP FROM WEATHERBELL

While widespread wind damage is the primary concern tonight, there is some minor tornado potential—especially in Essex County just after midnight. Again, the odds are low, but not zero.

Because of the overnight timing, it's extra important to have notifications enabled on your phone or weather radio. Make sure you have a way to receive alerts while you're asleep in case a warning is issued. Our free app is a great way to instantly get Environment Canada alerts, along with our custom notifications issued for your exact location.

SIMULATED RADAR - MAP FROM WEATHERBELL

The line of storms is expected to continue northeast through the early morning hours, bringing heavy rain, gusty winds, and frequent lightning to much of Southwestern Ontario and parts of the Greater Toronto Area between 3 and 6 AM.

While the line should gradually weaken during this time, it could still pack a punch in some localized areas. There’s some uncertainty around how long it will be able to hold its strength since the atmospheric environment in Ontario is notably weaker than what the storms had access to in the U.S.

Latest model runs show the system likely fizzles out once it reaches Lake Simcoe, meaning Eastern and Central Ontario probably won’t see much beyond a few scattered morning showers or storms.

Another round of storms is possible Friday afternoon and evening, particularly for Eastern Ontario and parts of Deep Southwestern Ontario. We’ll have more details on that in a separate update.

As it stands, the highest storm risk tonight is in Deep Southwestern Ontario, where we currently have a slight risk (2/5) for severe weather. The main hazard is damaging wind gusts between 12 and 6 AM, though isolated tornadoes and hail up to the size of quarters are also possible.

For the rest of Southwestern Ontario and the Golden Horseshoe, the risk is lower—a marginal (1/5) severe threat—with isolated pockets of wind damage being the most likely outcome. There’s also a very low tornado risk along the Lake Huron shoreline as the line initially pushes into the region. Hail up to the size of nickels could accompany some of these storms.

In addition to the overnight threat, a few isolated pop-up storms are possible during the late afternoon and early evening across parts of Grey-Bruce. While these are not expected to be severe, funnel clouds are possible, including a low-end risk of a landspout tornado. See our custom notification for more on the funnel cloud setup.

Stay weather-aware tonight. Keep your devices charged, notifications turned on, and have a plan in place just in case you need to take shelter quickly. We’ll continue to monitor the latest data and provide updates as the situation evolves, including a possible live stream later tonight.