Intense rainfall rates swamp parts of southern Ontario

You’ll want to leave plenty of extra time for the Tuesday commute, as heavy rain and thunderstorms impact travel across parts of southern Ontario. Widespread special weather statements and rainfall warnings cover the region, with as much as 50+ mm possible in some of the hardest hit areas that see thunderstorms. Because of the slow-moving nature of the storms, training in their nature, the threat of localized flooding is quite elevated in parts of the south. The rain will gradually ease through Tuesday evening, though the chance for a passing shower at times sticks with the forecast for much of this week. More on the timing and impacts, below. 

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THROUGH TUESDAY: WIDESPREAD WARNINGS IN EFFECT FOR HEAVY RAIN AND THUNDERSTORM THREAT

Widespread rainfall and patchy fog will continue from Windsor through the Greater Toronto Area (GTA) and towards Ottawa through Tuesday. A low-pressure system moved into Ontario Monday afternoon, bringing heavy rainfall across the region and a heightened risk for localized flooding. Special weather statements and rainfall warnings remain in place.

By late morning, rain will have departed the shores of Lake Huron and southwestern Ontario and the rain will come to an end by early afternoon in the GTA, though hanging on for eastern Ontario through the majority of the day.

A few embedded thunderstorms are still possible within the swath of rain as well.

In all, between 30-60 mm of rain is likely in the hardest-hit areas, along the Erie shores and 401 corridor stretching across the northern Greater Toronto Area, with locally higher amounts possible in areas that do see thunderstorms. 

As the cold front drapes across the Golden Horseshoe, winds will pick up in the late afternoon, with gusts of 40-50 km/h possible.

LOOK AHEAD: UNSETTLED CONDITIONS PERSIST WITH NO SIGNS OF HIGH HEAT

Conditions will largely improve by Tuesday night, though with the threat for a passing rain shower at times lingering into the end of the week. Widespread fog is likely to develop Thursday morning as well.

An upper level trough will continue to keep unsettled conditions nearby into the weekend across Ontario, as temperatures also remain seasonably cool into the weekend.

A flashback to this time last year and Toronto’s Pearson Airport had already recorded three days of temperatures over 30°C just a week into June. A couple of warmer days are expected during the middle of next week, though followed by cooler temperatures once again for next weekend.

Stay tuned to The Weather Network for all the latest on conditions across Ontario.