The Ottawa-Gatineau area is cleaning up from massive, powerful thunderstorms that struck the afternoon and evening of Canada Day — and doing so under a punishing heat wave with a risk of more storms.
Late Thursday morning Environment Canada issued a severe thunderstorm watch for the region, except for the Deep River and east Algonquin Park area.
Wind, heavy rain, lightning and hail are again possible Thursday afternoon and evening. There is also a tornado risk.
The watch is yellow, the most common and lowest level on Environment Canada’s three-colour scale.
What to do during a tornado alert
Watches mean severe weather is possible. Warnings mean it’s either happening or likely about to happen.
It’s the third straight day with a thunderstorm alert in the area.
Wednesday’s storm damage, including flooding, cancelled Ottawa’s part of national holiday celebrations.
Ottawa’s international airport weather station reported 99 millimetres of rain in fewer than four hours as of 5:45 p.m. Wednesday.
A total of 118 millimetres fell by midnight, according to Environment Canada, which is Ottawa’s rainiest July day and one of its rainiest days overall on record.
Extreme weather, including flooding, wipes out Canada Day activities in Ottawa
About 41,000 local customers didn’t have power as of around noon Thursday. The hardest-hit areas include Vallée-de-la-Gatineau, Tweed and Vanier.
Hydro Ottawa said late Thursday morning that flooding is making it more difficult to work on power outages in some areas.
Ottawa Mayor Mark Sutcliffe said Thursday morning there had been an “extraordinary” number of 311 requests for city service because of the weather and asked people to file reports online if possible.
Ottawa’s Ben Franklin Place service hub is closed because of flooding. There are currently no widespread flooding road closures.
Ottawa mayor on extreme Canada Day weather
The outages come during a heat warning that’s expected to peak Thursday with humidity making it feel like the 40s in many areas.
Ottawa is forecast to feel as hot as 46 on Thursday afternoon. Its hottest humidex on records that go back to the 1950s is 47, last felt on Canada Day 2018.
Ottawa’s humidex peaked at 43 on Wednesday before the storms.
Heat dome brings dangerous temperatures. Here’s how to stay safe
The dangerously hot weather is expected to last into the weekend in much of eastern Ontario, including Ottawa, Kingston and Cornwall.
Those communities are under an orange heat warning, meaning weather that should cause a significant disruption.
The rest of the region is under a more common yellow heat warning that could end on Saturday.
Gatineau has extended hours at some libraries, beaches and pools during the heat wave.
Ottawa Public Health (OPH) has an interactive list of places to cool off and advice for keeping cool in a home without power, such as closing blinds on the sunny side of a home, spending time in lower levels of a home and taking frequent cool showers or baths.
Other municipalities such as Kingston and Brockville have lists of places to cool down.
OPH and the Ottawa Riverkeeper each recommend not swimming in natural waters such as rivers for 24 to 48 hours after heavy rains because they can wash contaminants into the water.
