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
Indian envoy warns of 'big red line,' days after charges laid in Nijjar case
India's envoy to Canada insists relations between the two countries are positive overall, despite what he describes as 'a lot of noise.'
Stormy Daniels describes meeting Trump during occasionally graphic testimony in hush money trial
With Donald Trump sitting just feet away, Stormy Daniels testified Tuesday at the former president's hush money trial about a sexual encounter the porn actor says they had in 2006 that resulted in her being paid to keep silent during the presidential race 10 years later.
U.S. paused bomb shipment to Israel to signal concerns over Rafah invasion, official says
The U.S. paused a shipment of bombs to Israel last week over concerns that Israel was approaching a decision on launching a full-scale assault on the southern Gaza city of Rafah against the wishes of the U.S.
Former homicide detective explains how police will investigate shooting outside Drake's Bridle Path mansion
Footage from dozens of security cameras in the area of Drake’s Bridle Path mansion could be the key to identifying the suspect responsible for shooting and seriously injuring a security guard outside the rapper’s sprawling home early Tuesday morning, a former Toronto homicide detective says.
Northern Ont. woman makes 'eggstraordinary' find
A chicken farmer near Mattawa made an 'eggstraordinary' find Friday morning when she discovered one of her hens laid an egg close to three times the size of an average large chicken egg.
Susan Buckner, who played spirited cheerleader Patty Simcox in 'Grease,' dead at 72
Susan Buckner, best known for playing peppy Rydell High School cheerleader Patty Simcox in the 1978 classic movie musical 'Grease,' has died. She was 72.
Jeremy Skibicki has 'uphill battle' to prove he's not criminally responsible in Winnipeg killings: legal analysts
Accused killer Jeremy Skibicki could have a challenging time convincing a judge that he is not criminally responsible for the deaths of four Indigenous women, a legal analyst says.
Bye-bye bag fee: Calgary repeals single-use bylaw
A Calgary bylaw requiring businesses to charge a minimum bag fee and only provide single-use items when requested has officially been tossed.
Alcohol believed to be a factor in boating incident after 2 men die: N.S. RCMP
Two Nova Scotia men are dead after a boat they were travelling in sank in the Annapolis River in Granville Centre, N.S., on Monday.