Southern Ontario: Thunderstorm Outlook for Sunday, June 20, 2021
/Forecast Discussion
Thunderstorms are currently not expected in the forecasted region on this day.
Thunderstorms are currently not expected in the forecasted region on this day.
Thunderstorms are currently not expected in the forecasted region on this day.
There is the potential for some strong thunderstorm activity during the afternoon and evening on Monday as a cold front sweeps across the region. It’s currently uncertain exactly when this cold front will move through and storm development will be highly dependent on the timing of when this front moves through. Some models show it coming through earlier in the day which would mean storms would start to develop over Lake Ontario and Erie and track across upstate New York instead. The best chance at severe weather currently appears to be Eastern Ontario and around the Golden Horseshoe although this may shift. More details in future outlooks.
Thunderstorms are currently not expected in the forecasted region on this day.
Non-severe thunderstorms are possible throughout the afternoon and into the early evening hours of Saturday for areas around the Lake Erie shoreline including Extreme Southwestern Ontario. These storms could bring strong wind gusts, small hail and of course very heavy rainfall which could cause localized flooding. The storm threat will quickly come to an end after sunset.
Thunderstorms are currently not expected in the forecasted region on this day.
Thunderstorms are currently not expected in the forecasted region on this day.
A cluster of thunderstorms is expected to track across Southern Ontario during the morning hours on Friday with the highest chance for a thunderstorm around the Georgian Bay shoreline. These morning storms should remain non-severe although they could pose a localized flooding risk especially since many areas haven’t seen a lot of rainfall over the past few weeks.
The main story will be later in the day where there is an isolated severe risk during the afternoon and evening through parts of Southwestern Ontario around the Lake Erie shoreline. Storms are very likely to develop, but it’s unclear exactly where these storms develop. It’s possible we see them develop over Lake Erie and track stateside which would pose very little risk to the region. If they develop over Southwestern Ontario then we could see some damaging wind gusts, large hail and heavy rainfall from these storms around the Lake Erie shoreline and into the Windsor area.
Further north around Lake Simcoe and the GTA, there is a questionable severe risk if storms are able to develop early enough in the evening to take advantage of the environment which is looking unlikely at this point. As for the tornado risk, it appears the strongest tornado risk will remain south of the border although it can’t be fully ruled out if we get an isolated discreet storm that pops up in the prime environment.
Some storm development is possible overnight into Saturday however any storms that develop should be non-severe after sunset.
Thunderstorms are currently not expected in the forecasted region on this day.
Thunderstorms are currently not expected in the forecasted region on this day.
A decaying complex of thunderstorms could track into Southwestern Ontario during the early morning hours on Friday. Current data suggests it will survive overnight as it tracks across Michigan although it’s possible it could fizzle out before reaching the border. Thunderstorms are also possible across Southern Ontario later in the day and a few of these could pose an isolated severe risk. More details to come as the event draws closer.
A few non-severe thunderstorms may track into Northwestern Ontario late in the evening from Manitoba on Wednesday. These storms will quickly weaken by midnight as they move eastward across the region. The main risks with these storms are heavy rain, small hail, strong wind gusts and frequent lightning strikes.
Scattered non-severe thunderstorms may develop through parts of Northeastern Ontario during the afternoon and evening on Thursday. The exact intensity and coverage of these storms are uncertain at this time.
Thunderstorms are currently not expected in the forecasted region on this day.
Thunderstorms are currently not expected in the forecasted region on this day.
Thunderstorms are currently not expected in the forecasted region on this day.
Monday, June 14, 2021:
We’re watching closely for the potential of isolated severe thunderstorm this afternoon, evening, and into the overnight hours. For those wondering, isolated means that many who are highlighted in the yellow (2) risk area will not see a drop of rain from these storms.
However, we felt it was worth mentioning the risk as there is a fairly strong environment in place and we could see 2-5cm hail, 110km/h+ damaging wind gusts, frequent lightning, and perhaps even some very isolated flooding. A tornado risk is unlikely, especially if the storms show up into the overnight hours. Nevertheless, we’ll be watching closely and in the unlikely event of a Tornado Warning issued by Environment Canada, we’ll be posting it to all of our social media accounts and sending it out instantly on our free app; Instant Weather.
Environment Canada has issued Severe Thunderstorm Watches now for these risks and we’ve included them below:
Environment Canada also issued an experimental forecast map with similar locations highlighted to the watch regions:
PLEASE READ: For those wondering, these "prototype" maps are not yet available on EC's website. However, they will become operational soon and shared directly on their site. These forecasts and maps are issued by the same Environment Canada Meteorologists that issue all Watches and Warnings for the Alberta. They're also shared on Environment Canada's Twitter account and you can find it by searching for @ECCCWeatherAB.
Environment Canada's disclaimer says:
"Disclaimer: These products are part of an experimental initiative at Environment and Climate Change Canada (ECCC). These are not official ECCC products and therefore may not be available on a daily basis. Please continue to monitor weather forecasts as well as watches and warnings via http://www.weather.gc.ca/. Please address any questions, concerns and/or feedback regarding these products to the Decision Support Meteorologists at the Prairie and Arctic Storm Prediction Centre, available by email at ec.soutienmeteoouest-weathersupportwest.ec@canada.ca."
Long story short, please keep an eye out this afternoon, evening, and into the overnight for any alerts from Environment Canada and once again, you can get notified instantly of these alerts by downloading our free app; Instant Weather. Thank you so much to those who have downloaded it and a huge thank you to those who have subscribed to remove ads and upgrade to have 5 hours of future radar. More details, ASAP!
Thunderstorms are currently not expected in the forecasted region on this day.
Thunderstorms are currently not expected in the forecasted region on this day.
A few weakening non-severe thunderstorms over Eastern Ontario from Monday evening may linger into the early morning hours of Tuesday although it’s questionable if the storms can survive long enough. There is also a potential risk for thunderstorms later in the day in Extreme Eastern Ontario around the Cornwall area.