Rising thunderstorm risk, heat to mark Ontario's long weekend
Increasing warmth in southern Ontario brings the chance for thunderstorms this long weekend, with the threat expected to build towards the end of it
Keep an eye to the skies across Ontario this holiday weekend as rising heat and humidity will accompany a risk for thunderstorms throughout the province.
Your forecast doesn’t hold a complete washout by any means. But each day through early next week will hold the potential for rain and thunderstorms from northeastern Ontario to the southwestern corner of the province.
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Stay close to safe shelter if you have outdoor plans this weekend. If you can hear thunder, you’re close enough to get struck by lightning.
Rising instability pushes into Ontario to start the long weekend
Saturday will see warm temperatures surge into northeastern Ontario just as a cold front arrives in the region, providing the instability and trigger needed for thunderstorms to develop around communities including Timmins and Sudbury.
The main hazard with storms in northeastern Ontario will include strong wind gusts and large hail.
We’ll also see the potential for a few embedded thunderstorms to push into southern Ontario as some moisture and residual pre-dawn storm activity from Michigan slips through.
Approaching low kicks off multiple rounds of storm chances
Most of the province will be rain- and storm-free on Sunday. But forecasters will watch a low-pressure system track across the border toward northwestern Ontario late in the day.
We’ll see the threat for evening or overnight rain and thunderstorms for communities along the border between Ontario and Minnesota.
Nocturnal thunderstorms are possible across northeastern Ontario ahead of an approaching warm front. Heavy rainfall is the primary threat with the larger clusters of storms that propagate across northeastern Ontario through early Monday morning.
High moisture from the Gulf of Mexico, along with southerly winds, will push temperatures into the upper 20s across most of southern Ontario to begin the new week. Some areas could crack the 30-degree mark.
Additional thunderstorm activity is forecast Monday afternoon across northern Ontario, as the low-pressure system continues to advance northward.
Tuesday’s storm chances bubble across central and southern Ontario as the Colorado low’s cold front slices into widespread heat and humidity parked over the region.
Heavy rainfall will be the primary threat, along with small hail and gusty winds, but the cold front is still well east, so storms are forecast to be isolated in nature--triggered by lake-breeze boundaries and modest convergence.
The cold front is forecast to move through by early Wednesday morning, bringing non-severe storms across the region and an end to the region's heat.
Thunderstorm safety is vital on a holiday weekend
A warm holiday weekend guarantees that plenty of folks will spend time outdoors in the days ahead, making thunderstorm safety paramount.
Lightning can strike dozens of kilometres away from the heart of a storm. If you’re close enough to hear thunder, you’re close enough to get struck by lightning. If someone nearby is struck by lightning, don’t wait to render aid! It’s a myth that it’s dangerous to touch a lightning strike victim.
Severe weather can strike suddenly. Flying debris and falling trees are a significant hazard during a storm’s sudden high winds. Large hail is dangerous to anyone caught outdoors.
Make sure you have a way to receive severe weather warnings the moment they’re issued.