Slight Risk for Severe Thunderstorms in Southern Manitoba This Afternoon and Into Tuesday Morning

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Following some morning and early afternoon rain, Southern Manitoba can expect more active weather with severe thunderstorms beginning this afternoon and continuing into Tuesday morning. The possibility of large hail and flooding caused by heavy downpours make this a Slight Risk in Southeast and South-Central Manitoba.

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The activity will begin this afternoon with a line of storms pushing northeastward into the region from North Dakota. Development of further storms will continue through the evening and into the pre-dawn hours of Tuesday, resulting in some locations seeing multiple rounds of thunderstorms. The storms that develop later into the evening could be more organized and are expected to be stronger that the afternoon storms.

These storms may bring some large hail, up to the size of a timbit, as well heavy rains that could result in areas of localized flooding. There will be some strong wind gusts that are expected to top out in the 90-100 km/h range and the possibility of an isolated tornado can not be completely ruled out.

Eyes to the Sky! Northern Lights Could Make an Appearance Across Canada on Monday

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A powerful solar flare, reaching an impressive X4.5 rating, erupted on Saturday, sending an Earth-directed coronal mass ejection (CME) into space. This CME is expected to impact our planet, sparking geomagnetic storm conditions that could bring the northern lights much farther south than usual across Canada on Monday.

As with most space weather events, there is some uncertainty regarding the exact timing of the CME's arrival. According to the latest data, the strongest storm conditions are anticipated during the mid to late morning hours on Monday, gradually weakening throughout the day. This suggests the best viewing opportunity for the auroras may occur in the pre-dawn hours, particularly in Western Canada.

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However, this isn’t set in stone. Space weather forecasting can be tricky, and the CME might arrive later than expected, which would actually be the ideal outcome for North American skywatchers. A delayed arrival could mean a spectacular display of the northern lights over large portions of the country on Monday night.

The Space Weather Prediction Center (SWPC) is forecasting a "strong" geomagnetic storm (G3 on a scale of 5) to develop sometime on Monday. A G3 storm is potent enough to make the northern lights visible across much of Canada, provided the conditions align just right.

Historically, storms of this strength have allowed auroras to be seen as far south as Southern Ontario, and sometimes even into northern parts of the United States. In fact, the SWPC mentions the possibility of auroras being visible as far south as Pennsylvania and Iowa.

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Based on the SWPC’s latest forecast, the geomagnetic storm is expected to peak between 5 AM and 11 AM EDT (2 AM to 8 AM PDT). A moderate (G2) storm is projected to continue through the day, potentially lasting until 11 PM EDT (8 PM PDT).

If this timing holds, the best chances to witness the northern lights would be in Western Canada during the early morning hours on Monday, when the storm is at its peak. Unfortunately, for those in Ontario and Quebec, the storm may hit after sunrise, reducing the likelihood of a good aurora display.

That said, if the CME arrives later in the day, it could extend the storm into Monday night, offering a better chance for Eastern Canada to catch the auroras, assuming clear skies.

IMAGE FROM WeatherBell

Speaking of skies, Monday night’s cloud forecast looks promising for much of Canada. The latest model shows most areas should have a good view, with only Southeastern Manitoba, Northwestern Ontario, and Northern Quebec facing potential cloud cover that might obscure the show.

Southern Saskatchewan and Northern Alberta may see patchy clouds but could have breaks offering decent aurora visibility. For Southern Ontario, Quebec, and most of Western Canada, skies are expected to remain clear.

Check out our free app, Instant Weather for a more in-depth cloud coverage forecast specific to your exact location.

Another potential issue will be the full moon leading to the possibility of the northern lights appearing more dim and harder to spot. However, if the storm is as strong as forecasted, there still should be some chance to capture the show despite the bright moon.

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Northern regions of Canada, especially Northern Quebec, the Prairies and British Columbia, are almost guaranteed to see the northern lights, except for areas in Southwestern BC near Vancouver where visibility is less certain.

Zooming into more southern regions, the likelihood of seeing auroras becomes more variable. Northeastern Ontario, including Sault Ste. Marie, Sudbury, and North Bay, along with Western and Northern Quebec, have a strong chance of aurora sightings.

In Central Ontario, places like Muskoka, Algonquin Park, Bancroft, and the Ottawa Valley also have a moderate chance, as do areas around Montreal. However, the timing of the storm’s arrival remains a key factor—if it’s delayed and peaks closer to sunset, a G3 storm would likely provide an opportunity for these regions to witness the lights.

In Southwestern Ontario, the Golden Horseshoe, and southern Quebec near the American border, the probability becomes more uncertain. There’s a low to slight chance of auroras being visible here, depending on whether the storm overperforms or peaks later in the night.

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It’s important to keep in mind that light pollution can drastically affect your ability to see the northern lights. Urban areas, in particular, can drown out the skies, so you’ll need to find a dark spot away from city lights for the best chance to see the show. A resource like DarkSiteFinder can help you locate areas with low light pollution for optimal aurora viewing.

Northern Lights Timing

Many are accustomed to the precise scheduling of weather events, from thunderstorms and winter weather to solar eclipses, where timing is crucial. It’s understandable, then, that there’s a desire for a similar pinpoint timing for the best viewing of the aurora. However, the reality of predicting the best time to view the northern lights is not so straightforward.

Here’s the deal: Unlike weather events driven by terrestrial conditions, the aurora is influenced by solar activity, which is far less predictable. We can estimate that the northern lights are best viewed from just after sunset to just before sunrise, provided the skies are dark and clear. Beyond that, precise timing for peak aurora activity is challenging to forecast with current technology.

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Space weather forecasting doesn't yet allow us to predict exactly when solar energy will impact Earth. We know it's coming, but how and when it interacts with our planet's magnetic field can vary. Often, we only have a few hours' notice before the solar energy is detected by satellites.

Furthermore, the intensity of the northern lights can fluctuate significantly over short periods. You might have noticed this variance if you've observed the lights before—periods of dim activity suddenly bursting into vibrant colors. This is due to the variable concentration of solar particles interacting with our atmosphere.

While we can inform you a few hours ahead when conditions are likely to be good, predicting the exact peak of aurora activity is akin to forecasting the peak of a meteor shower; we know the best night but not the best hour.

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Threat of Massive Hail is the Driving Force Behind a Widespread Strong Severe Risk in Southeast Manitoba Sunday Afternoon IF Storms Develop

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It’s been a very active few days across the Prairies and this morning was no exception, with destructive wind gusts pummelling parts of East Central Saskatchewan and the Westman and Parkland Regions.

Unfortunately, this trend of dangerous severe weather will likely continue this afternoon, but this time the target will be Southeastern Manitoba. The possibility for massive hail across the region has resulted in this being a widespread Strong Risk for severe thunderstorms for this afternoon.

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Once again, weather models are struggling with pinpointing these storms, but the ingredients for severe weather should all be in place and there is a potential for severe storm development, which warrants a forecast. Today will be an “IF day” in the sense that IF storms end up developing, they are expected to be very strong and widespread across the region. With the intense heat and temperatures feeling into the low 40s, along with ample moisture and instability, the environment will be primed for storms, but a strong enough trigger will be necessary for them to occur.

This storm development could begin early this afternoon, as the existing line of storms pushes northeastward through the Interlake Region. Behind this, additional storms could develop along a cold front and make their way eastward through the Red River Valley and Interlake Region during the afternoon and the Eastman and North Eastman Regions in the evening and overnight hours. Whether or not this development actually occurs is still uncertain.

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If the severe thunderstorms end up developing this afternoon, the major threat will be very large hail. Golf ball-sized hail appears to be likely with these potential storms, with even up to tennis ball-size possible. Widespread damaging wind gusts over 100km/h would also be associated with these storms, as well as up to 100mm of rain resulting in localized flooding and the possibility of a tornado.

This could very well end up being a bust, but the threats involved in the event that storms do develop are quite significant and it’s important to be prepared.

Greatest Severe Thunderstorm Threat for Saturday Afternoon Shifted West; Still Slight Risk for Southern Manitoba

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Following this morning’s thunderstorms, we are still expecting more severe weather for Southern Manitoba later today, however the anticipated strength of those storms has diminished and the area they’re expected to hit has also changed. The strongest storms of the day are now expected in Southern Saskatchewan, but the potential for damaging winds, large hail. and localized flooding still result in a Slight Risk for severe thunderstorms in the Westman, Parkland and Northern Interlake Regions.

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The exact timing of these storms is tricky to establish due to uncertainty between weather models, leaving three possible scenarios.

Scenario 1

Large storms could begin to develop in the mid-afternoon just east of the Saskatchewan border in the Parkland Region as isolated supercells which would travel northeastward across the province. Development of additional storms would continue through the evening and early overnight, following the same northeastward trajectory. These storms would then be followed by a more organized cluster of storms crossing through the region Sunday morning.

Scenario 2

Smaller storms could start to develop in the Parkland Region in the mid to late afternoon and quickly become more organized into a strong line that spreads into the Northern Interlake and travels southeastward through the evening before starting to fall apart approaching the Central Plains overnight. In this scenario, the storms Sunday morning would be weak, if they occur at all.

Scenario 3

A handful of small storms could pop-up starting in the later in the afternoon, once again in the Parkland Region, and continuing into the late evening, but not amount to anything too concerning. Then, in the early morning hours, a large cluster of storms could push northeastward into the region from Saskatchewan, followed by a second round of strong storms later in the morning.

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Regardless of which of the three scenarios unfolds, it is likely that there will be strong storms in Manitoba over the next 24 hours. The threats from these storms will be the large hail, with up to toonie-size likely and damaging wind gusts that could exceed 100km/h, as well as one or two tornadoes . There is also the concern of localized flooding because these storms are expected to occur over the same area. It’s important to note that the level of uncertainty between weather models means that this could very well end up being a classic “bust” day, but we believe that it is better to be prepared in the event that any one of these scenarios materializes.

Slight and Strong Risk for Severe Thunderstorms Across Southern Manitoba Saturday, Hitting in Multiple Rounds

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It will be a hot day across Southern Manitoba on Saturday, but there will be some active weather, in the form of a line of severe thunderstorms, to contend with before the temperatures start to climb. More storms will hit the region later in the day, but the timing remains a little unclear. Regardless, the risk of large hail and damaging wind gusts, along with the possibility of a tornado makes this a Strong Risk for severe thunderstorms in Southwestern Manitoba, including Brandon, and a Slight Risk across much of the rest of Southern Manitoba.

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The first line of storms will make their way into Southwestern Manitoba around sunrise Saturday morning, packing a punch with strong winds and large hail. These storms will lose steam as they travel eastward across the width of the province throughout the morning and into the early afternoon. Following this line of storms, it will be a hot day across the region, feeling closer to 40°C with the humidity, which should provide ample fuel for another wave of storms. The exact timing of this second line of storms is still uncertain. Some models are suggesting that the additional storms could start Saturday evening and make their way across Southern Manitoba overnight and into Sunday morning. On the other hand, there are other models that show the second line of storms developing in the early morning hours of Sunday and continuing into the early afternoon, followed by a third line of storms beginning Sunday evening. Due to this uncertainty, we will likely have a revised forecast for the secondary storm development posted Saturday afternoon.

The threats from these storms will be the large hail, with up to golf ball-size possible, as well as widespread damaging wind gusts that could exceed 100km/h and approach 120km/h, along with the possibility of a tornado or two touching down. There will also be a flooding risk, with these storms expected to bring up to 100mm, particularly to areas that will experience multiple rounds of storms.