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
Debunking the 'anti-sunscreen' movement: Doctors say TikTok trend is dangerous
Dermatologists are sounding the alarm about misinformation from the anti-sunscreen movement, saying not wearing sunscreen can cause cancer and other problems.
MPs to vote on motion to oust House Speaker Greg Fergus over allegations of partisanship
Members of Parliament will be voting Tuesday on a Conservative-led motion to oust House of Commons Speaker Greg Fergus, amid renewed concern over his 'alleged lack of impartiality.'
Richard Dreyfuss' comments about women, LGBTQ2S+ people and diversity lead venue to apologize
The actor Richard Dreyfuss showed up in a dress at a 'Jaws'-themed event in Massachusetts, where the blockbuster 1975 movie he starred in was shot, and then proceeded to make demeaning remarks about women, LGBTQ2S+ people and diversity.
Here's how new AI tech could change the iPhone
Generative AI, artificial intelligence that can provide thoughtful and thorough responses to questions and prompts, could potentially breathe new life into Apple’s iPhone lineup at a time when competitors are threatening to leave the company behind in the race to shape what could be a world-changing technology.
WATCH Airline pilot treated to stunning northern lights show during U.S.-Portugal flight
An airline pilot got quite a show on May 11 while flying from San Francisco to Lisbon when a solar storm caused stunning auroras.
Severe thunderstorms, 15 cm of snow: Canadian weather forecast highlights
Well into spring, some parts of Canada could experience a wintry comeback, while other areas are bracing for severe thunderstorms, according to local forecasts.
Ont. university says professor fired over 'unethical' sexual relationships with students
An associate professor at McMaster University has been fired after its board of governors found that he engaged in 'unethical, inappropriate and in some instances exploitative' sexual relationships with students.
Why young people keep getting caught in debt traps and how to break the cycle
Canadians are feeling the squeeze between incomes that haven't kept up with the cost of living, housing crises in markets across the country and rising interest rates brought in to control inflation. Experts share some tips for managing debt and spending.
Tornado touches down west of the Island of Montreal
Emergency services in the town of Rigaud, Que. are investigating after a tornado touched down shortly after 5:30 p.m. Monday.