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
'One of the single most terrifying things ever': Ontario couple among passengers on sinking tour boat in Dominican Republic
A Toronto couple are speaking out about their “extremely dangerous” experience on board a sinking tour boat in the Dominican Republic last week.
Half of Canadians have negative opinion of latest Liberal budget: poll
A new poll suggests the Liberals have not won over voters with their latest budget, though there is broad support for their plan to build millions of homes.
opinion Why you should protect your investments by naming a trusted contact person
Appointing a trusted person to help with financial obligations can give you peace of mind. In his personal finance column for CTVNews.ca, Christopher Liew outlines the key benefits of naming a confidant to take over your financial responsibilities, if the need ever arises.
Teacher shortages see some Ontario high school students awarded perfect grades on midterm exams
Students at a high school in York Region have been awarded perfect marks on their midterm exams in three subjects – not because of their academic performances however, but because they had no teacher.
'My stomach dropped': Winnipeg man speaks out after being criminally harassed following single online date
A Winnipeg man said a single date gone wrong led to years of criminal harassment, false arrests, stress and depression.
Ottawa injects another $36M into vaccine injury compensation fund
The federal government has added $36.4 million to a program designed to support people who have been seriously injured or killed by vaccines since the end of 2020.
Photographer alleges he was forced to watch Megan Thee Stallion have sex and was unfairly fired
A photographer who worked for Megan Thee Stallion said in a lawsuit filed Tuesday that he was forced to watch her have sex, was unfairly fired soon after and was abused as her employee.
An Ontario senior thought he called Geek Squad for help with his printer. Instead, he got scammed out of $25,000
An Ontario senior’s attempt to get technical help online led him into a spoofing scam where he lost $25,000. Now, he’s sharing his story to warn others.
Her fiance has been in prison for 49 years. She's trying to free him before it’s too late
She was lying in bed on a Thursday morning, thinking about the man she loved, hoping to win his freedom before time ran out.