Thunderstorm Outlook
Valid: Tuesday, June 2 - Wednesday, June 3, 2020
Forecaster: Brennen Perry
Thunderstorm outlook map
NOTE: The tornado risk zone outlines the region with the highest probability of tornadoes, but tornadoes may occur outside of the zone.
Timing |
Southwestern: 6PM - 10PM
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Not sure what region you are in? Click here for a map showing the regions across Southern Ontario. Northeastern Ontario is north of North Bay (not shown on map).
Thunderstorm Threatcast
Thunderstorm Confidence |
High (75%) |
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Severe Confidence |
Moderate (50%) - 'Bust' Possible |
Tornadoes |
One or Two (Potentially Sig.) |
Max Wind Gusts |
100+ kmh | 62+ mph |
Max Hail Size |
Golf Ball |
Max 24-hr Rainfall |
~50 mm | ~2" |
Forecast Discussion
Issued: Tuesday, June 2, 2020 - 4:05PM
The environment is favourable for significant severe thunderstorms throughout parts of Southwestern Ontario, Grey-Bruce/Simcoe County and into the Golden Horseshoe late Tuesday afternoon extending through the evening hours. Now, there is an important caveat with the severe risk as it’s fully dependent on IF storms can develop in time to take advantage of the prime environment. If we don’t get any storms then obviously the severe risk is non-existent and some models suggest that storm development is questionable. Timing is also a huge factor because the severe threat quickly diminishes after sunset due to the lack of daylight heating so we have a short window between 5 PM and 10 PM where the best environment is available for any storm that develops.
With that being said, we believe the highest severe risk is located in a zone stretching from Kincardine through the Orangeville area and into the GTA. IF storms develop we expect them to show up somewhere between Shelburne and Hanover around the dinner hour and slowly track to the southeast throughout the evening. Any storm(s) that develop within this zone has the potential to produce very large hail up the golf ball size along with damaging wind gusts and heavy rainfall. We may also see one or two tornadoes (maybe even a significant tornado if everything comes together at the right time) within this area although it’s not a guarantee. The mature cluster of storms will track over Lake Ontario and may make landfall over parts of the Niagara region just before midnight before tracking stateside. We expect the main threat at this time to be more focused on damaging wind gusts, but again we can’t rule out a tornado although the probability is much lower later in the evening.
Another round of storms is expected to affect Extreme Southwestern Ontario early Wednesday morning starting around 3 AM as a line of thunderstorms with embedded severe storms move in from Michigan. The main threat with this line will be 90-100km/h wind gusts and heavy rainfall - the hail and tornado risk is minimal given the storm mode and timing. All thunderstorm activity will clear out of our region by late Wednesday morning.
