A stubborn summertime pattern will persist over parts of Ontario and Quebec to start the week, bringing the region another round of muggy temperatures and a risk for severe thunderstorms. Some of the storms could produce strong wind gusts, torrential rainfall, and small hail. Unsettled conditions could return later in the week around Canada Day. More on Monday’s storm threat and beyond, below.
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MONDAY: SEVERE STORMS POSSIBLE AS HEAT AND HUMIDITY BUILD ONCE AGAIN
A steamy air mass will remain in place over southern Ontario and Quebec as southerly winds pump warm and humid air over the region. Environment and Climate Change Canada’s heat warnings for southeastern Ontario and southern Quebec will continue through Monday, as humidex values could approach or exceed 40 in some locations.
A stalled boundary across the region will provide another opportunity for showers and thunderstorms to bubble up in the afternoon heat.
Monday won’t be a washout, but showers and thunderstorms are possible in the afternoon and evening hours across southwestern Ontario. Some of these storms could turn severe, with strong wind gusts, torrential rainfall, and small hail possible.
Severe storms are also possible on Monday in portions of southeastern Quebec and southern New Brunswick, including the cities of Sherbrooke and Fredericton.
VACATION ALERT: STALLED BOUNDARY LEADS TO SWATH OF HEAVY RAINFALL THROUGH THE WEEK
Later in the week, widespread showers and thunderstorms could affect vacation plans and the Canada Day holiday.
A daily threat for rain and thunderstorms, with some peeks of sunshine in between, could bring more than a month’s worth of rainfall to some communities over the next week. Drought-busting rains will bring totals of 50-100 mm over the next 7 days, temporarily eliminating the risk for forest fires.
"Of course this is disappointing news for those on vacation, however, there will also be periods of dry weather with sunshine and warm temperatures," says Dr. Doug Gillham, a meteorologist at The Weather Network. "So, it will not be as miserable as it may look if you just quickly glance at the weather icons in your forecast for the week."
The threat for showers and thunderstorms is expected through at least Friday, with a few days of cooler weather are expected as we head through next weekend -- thanks in part to a recurving typhoon in the western Pacific.
However, forecasters are still watching the potential for a period of very warm to hot weather after July 5.
Be sure to check for the latest updates on the weather in your area.