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
'Some structural damage' from wildfire near Fort Nelson, B.C., mayor confirms
More than one home has been damaged or lost due to a massive wildfire outside of the B.C. community of Fort Nelson, the mayor confirmed Wednesday.
'Very expensive lunch': Sask. driver says he got a cellphone ticket for using his points app in the drive-thru
A warning from a Saskatoon driver about using your fast-food app while in the drive-thru line — a trip to get some free lunch cost him a lot more than he bargained for.
B.C. YouTuber ordered to pay $350K for 'relentless' online defamation campaign
An 'unrepentant' YouTuber has been ordered to pay $350,000 in damages as compensation for a 'relentless' campaign of defamation waged online against a business owner and his company, the B.C. Supreme Court has ruled.
Chief says grave search at B.C. residential school brings things 'full circle'
Chief Robert Michell says relief isn't the right word to describe his reaction as the search begins for unmarked graves at the site of a former residential school he attended in northern British Columbia.
'Endless Shrimp' just one misstep for Red Lobster as it eyes bankruptcy protection
While it's unclear what these closures might mean for the 27 restaurants in Canada, Red Lobster is expected to file for bankruptcy protection in the U.S. this month.
B.C. man shot sex worker in the back during drug-fuelled birthday, court hears
A man from B.C.'s Lower Mainland has been sentenced to four years behind bars after shooting a sex worker in the back during a drug-fuelled 43rd birthday.
'Inhumane conditions': 68 dogs pulled from Winnipeg home
Nearly six dozen dogs were seized from a home Wednesday morning by the Winnipeg Humane Society. It is the largest known seizure of animals in the city’s history.
Ontario's 'Crypto King' Aiden Pleterski arrested
Of the $40-million Aiden Pleterski was handed over two years, documents show he invested just over one per cent and instead spent $15.9 million on "his personal lifestyle." The 25-year-old Oshawa, Ont. man was arrested and charged with fraud and money laundering on Tuesday.
Driver said he smoked pot oil, took medication before Florida crash that killed 8 Mexican workers
A man with a long record of dangerous driving told investigators he smoked marijuana oil and took prescription drugs hours before he sideswiped a bus, killing eight Mexican farmworkers and injuring dozens more, according to an arrest report unsealed Wednesday.