What is a 'derecho'? Climatologist explains Saturday's powerful storm
The storm that moved across Ontario and Quebec Saturday is known as a “derecho” (da-RAY-cho), a powerful kind of windstorm that is long lasting and far-reaching.
The derecho storm that slashed across southern Ontario and Quebec before moving into Maine left a path of destruction in its wake, and was responsible for at least eight deaths, including three in eastern Ontario.
Environment Canada Senior Climatologist David Phillips explains that a derecho is not a common term.
“It’s not a word we use very often because they don’t occur that often,” he told Newstalk 580 CFRA’s ‘CFRA Live with Andrew Pinsent’ on Sunday. “It’s sort of like a microburst or a thunderstorm but you get a whole army of those. Imagine soldiers lined up and just mowing down the front lines as they move along. Meteorologically, that’s essentially what happens.”
The storm moved into Canada from Michigan at around 11 a.m. Saturday, hitting London, Ont., Kitchener-Waterloo, Toronto, Kingston, and Ottawa, before moving up into Quebec and then to Maine.
“This storm was almost about 1,000 kilometres from Michigan to Maine as it went across Ontario and Quebec. That’s what a derecho is, it’s a long line of very active thunderstorms or microburst kind of situations. Nothing can deter it. It just marches along,” said Phillips.
Phillips said a derecho often has tornado-like or even hurricane-force winds. Ottawa saw wind gusts of up to 120 km/h and other locations saw even stronger winds.
But tornadoes, which are rotational storms, can still be embedded in the generally straight line of a derecho.
“There could be tornadoes embedded in that kind of derecho. I haven’t heard of a tornado report, but it doesn’t mean it can’t produce it,” he explained.
Western University’s Northern Tornadoes Project says it is investigating in the Uxbridge, Ont. area and just south of Ottawa, for evidence of possible tornadoes.
Just last week, the Northern Tornadoes Project confirmed an EF0 landspout tornado in the Casselman area, Ontario’s first tornado of the 2022 season.
Phillips says May can be a fickle month when it comes to the weather.
“You have that combination of warm, humid air that’s possible,” he said, noting the storm moved in when it was 30 degrees with a humidex of 38 on Saturday. “There is always that possibility of warm air in May, but the cold air in May is never too far away.”
It’s when cold, dry air hits warm, moist air that powerful storms can be produced, Phillips said.
“You can get air mass thunderstorms in July, but what you’re getting in May is that combination of the warm air duking it out with the cold air. In the springtime, this is why you can get some violent weather,” Phillips said.
“When you get that kind of one atmosphere changing to another, it’s usually heralded by some wild weather, and there it was.”
CTVNews.ca Top Stories
BREAKING Indigo Books & Music shareholders vote to approve privatization sale
Indigo Books & Music Inc. shareholders have voted to approve a deal that will see the retailer become a private company. The offer of $2.50 per share comes from Trilogy Retail Holdings Inc. and Trilogy Investments L.P., which have a 56 per cent stake in Indigo and are owned by Gerald Schwartz, the spouse of Indigo chief executive Heather Reisman.
Latest deadly weather in U.S. kills at least 20 as storms carve path of ruin across multiple states
Powerful storms killed at least 20 people, injured hundreds and left a wide trail of destruction across Texas, Oklahoma and Arkansas after obliterating homes and destroying a truck stop where dozens sought shelter during the latest deadly weather to strike the central U.S.
What Canadian grocery shoppers need to know about anticompetitive allegations
Amid mounting outrage over high grocery prices, a retail expert says there's a solution to fostering more competition in the country.
Arrests made in 'highly orchestrated' GTA auto theft operation: police
Peel Regional Police say they have arrested 16 suspects and issued arrest warrant for another 10 individuals in connection with an auto theft investigation carried out by a 'highly orchestrated criminal operation.'
North Korea launched a rocket likely carrying a second spy satellite. It's unclear if successful
North Korea launched a rocket likely carrying its second military spy satellite on Monday night, hours after its announcement of a plan to put a satellite into orbit drew strong rebukes from its neighbours.
She developed a passion for genealogy while finding her roots. Now she helps others find their own
Lauren Robilliard always knew she was adopted. As the B.C. native grew older, she developed a passion for genealogy, tracing her roots and paving the way for a career to help others find their own.
Former 'General Hospital' actor Johnny Wactor fatally shot in Los Angeles
Former 'General Hospital' actor Johnny Wactor was fatally shot in downtown Los Angeles while interrupting thieves Saturday, according to his agent and CNN affiliate KABC.
Israeli attack on Rafah tent camp kills 45, prompts global outcry
An Israeli airstrike triggered a massive blaze killing 45 people in a tent camp in the Gaza city of Rafah, officials said on Monday, prompting an outcry from global leaders who urged the implementation of a World Court ruling to halt Israel's assault.
A cross-country look at beer and wine in convenience stores
By Labour Day weekend, Ontarians of legal drinking age could snag a six-pack at their local convenience store on the way to the cottage. But what are alcohol sales like across the country? Here's what we know.