Environment Canada has issued a tornado watch for Ottawa and the surrounding area, warning of severe thunderstorms that could also produce strong winds, large hail and heavy rain.
The weather agency issued the advisory just before 11:30 a.m. Tuesday, warning conditions are favourable for the development of severe thunderstorms starting early this afternoon which may produce tornadoes.
“This is a dangerous and potentially life-threatening situation,” Environment Canada said. “Take cover immediately if threatening weather approaches.”
Strong winds, large hail and heavy rain are also possible, the watch says. The weather agency is warning of “a tornado or two possible,” storms with wind gusts of up to 110 km/h and nickel to ping pong ball-sized hail.
“Thunderstorms are expected to develop early this afternoon with the potential for quick intensification as they progress eastward. A tornado or two will be possible this afternoon before the threat transitions to primarily wind.”
The tornado watch also encompasses areas around Ottawa, including west to the Ottawa Valley, as far south as South Frontenac and as far east as Prescott-Russell.
Tornado watches are issued when conditions are favourable for the development of thunderstorms that could produce tornadoes.
Environment Canada recommends taking the following actions in the event of a tornado:
Go indoors to a room on the lowest floor, away from walls and windows
Leave mobile homes, tent, trailers and other free-standing structures and move to a strong building
As a last resort, lie in a low spot and protect your head from flying debris
Meterologists warn of conditions ripe for ‘likely tornado’
The tornado watch comes as Ottawa and eastern Ontario residents are being advised to monitor weather warnings on Thursday. Meteorologists warn the weather conditions will provide “significant ingredients” for a “likely tornado.”
Earlier Thursday, Environment Canada issued a tornado watch for parts of west Quebec near Ottawa, including the Fort William, Shawville, Rapides-des-Joachims, Lièvre River, Low, Wakefield, Maniwaki, Gracefield, Papineauville, Chénéville and Papineau-Labelle Reserve areas.
Western University’s Northern Tornadoes Project issued a tweet Wednesday saying its Day 2 outlook has meteorologists “expecting sufficient ingredients to come together in parts of (eastern) Ontario and (southern) Quebec (Thursday) for a ‘Likely Tornado’ threat.”
“Conditions are favourable for the development of severe thunderstorms that could produce tornadoes this afternoon,” the weather agency warned. “This is a dangerous and potentially life-threatening situation.”
Environment Canada’s forecast calls for a 60 per cent chance of showers or thunderstorms this afternoon, with a high of 28 C. It will feel like 37 degrees with the humidex.
David Sills of the Northern Tornadoes Project tells CTV News Ottawa people should “pay close attention” to Environment Canada warnings.
“NTP meteorologists produce a tornado forecast to make sure our damage survey teams are prepared for action,” Sills said.
“The forecast for (Thursday) includes an area of eastern Ontario and southern Quebec where ingredients are likely to come together to form severe storms and the threat of a tornado. Given the amount of damage in these areas from the May 21 derecho, we’re, of course, hoping that the computer model guidance and our interpretation of it is wrong and we’ll get through tomorrow without additional damage.”
CTV News at Five anchor Matt Skube asked about the ingredients that could trigger a tornado in Ottawa.
“We’ve got this cold front coming through tomorrow, lots of warm moist air ahead of it and we need wind shear, we need an increase of wind speed with height in the atmosphere in order to get storms that are well organized and could produce severe weather,” Sills said.
Sills says there is a “good chance” of severe storms in an area including Toronto and Kingston, while for the Ottawa region the “likelihood is higher that a tornado will occur.”
Environment Canada senior climatologist David Phillips says Environment Canada classifies the risk of a severe thunderstorm in the Ottawa and eastern Ontario region on Thursday as “medium.”
“Keep an eye on the sky and the forecast close by and do the right thing if it does break out. My sense is that it’s just a medium kind of risk,” Phillips told Newstalk 580 CFRA’s Ottawa Now with Kristy Cameron. “We could end up with a bit of wind and a short lived thing, but with no kind of rotating clouds or twisters that will occur in your listening area.”
Phillips says the hot and humid temperatures in the forecast on Thursday will be “fuel in the air” as a cold front moves through the area.
“It’s going to be an undercutting cold front that’s going to take that fuel, that heat and humidity, and push it up and just give it a little bit more, like steroids, like an oomph you say, so that can lead to severe thunderstorms,” Phillips said. “Not every severe thunderstorm has a tornado; thankfully, I think less than 10 per cent. But the strong winds can blow things around, you can get hail that can be golf ball size and some torrential rains.
“Yes, there can be the pop-up kind of tornado that can hit there or over there, so that’s one we have to always be mindful of.”
The Northern Tornadoes Project’s warning of a “likely tornado” comes weeks after a powerful derecho caused widespread damage on May 21.
“I can understand the people of eastern Ontario being a little threatened. You’ve had tornadoes back there in September 2018, some of the most powerful tornadoes in eastern Canada in years, and then you had one on June 2 the following year, less than nine months and you sort of had back-to-back tornado events,” Phillips said.
“Then of course you had the big derecho that came through Ontario on May 21, so I think you maybe feel your snake bite and I think anytime severe weather comes up there’s some nervousness.”
The first tornado of the year in Ontario was spotted near Casselman last month. The Northern Tornadoes Project said an EFO landspout tornado formed on May 15.