Sarah Bauer woke up to a shaking house.
She thought an earthquake might have struck near her home in Torrance, a village in Ontario’s cottage country.
But when she looked outside, she saw that a massive tree had collapsed on her driveway under the weight of the rapidly accumulating snowfall, taking a power line with it.
“It was weird,” she said.
The storm that hit parts of central Ontario in late November and early December was the largest in recent memory, meteorologists said, reportedly dumping 140 centimeters on Gravenhurst, a town just south of Torrance .
Another round of intense lake-effect snowfall hit areas off Lake Huron again this week, with more flurries expected over the weekend.
The regions off the Great Lakes are accustomed to heavy snowfall, earning them the title of Ontario’s snow belt.
Yet something new is happening. Climatologists and meteorologists say climate change, driven by the burning of fossil fuels, is helping create conditions that can make storms stronger.
Richard Rood, a climatologist who studies the Great Lakes, says lake-effect snowstorms will likely intensify as the planet warms.
“They’re probably better interpreted as typical of the future rather than extreme relative to the past,” said Rood, professor emeritus of climate and space sciences at the University of Michigan in Ann Arbor.
Lake-effect snow relies on a combination of a surge of cold air from the Arctic and the comparatively warmer water of the Great Lakes. As air passes over the lake, it absorbs moisture and dumps it onto downwind communities during snowfalls often characterized by intense, localized gusts.
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These storms are typical in late fall or early winter, when lake temperatures are still relatively warm. In the depths of winter, ice cover helps stop evaporation, meteorologist Arnold Ashton said.
“Typically it’s not as common in January, February – and certainly February – because there’s more ice on the lake,” said Ashton, a senior meteorologist with Environment Canada.
But as the lakes warm, there is more heat and humidity that arctic air blasts can capture, intensifying snowfall. And as warmer winters limit the amount of ice cover, these storms can expand later in the season.
“Gravenhurst’s apocalyptic meter and a half of snow occurred in late November, early December… but with global warming, these events could persist,” Ashton said.
Gravenhurst was under a local state of emergency for more than two weeks as crews cleared snow-covered roads and attempted to restore power to tens of thousands of customers. Stranded drivers had to be rescued on a highway that remained partially closed for almost three days.
After cutting down the collapsed tree in front of their driveway, the Bauer family of Torrance purchased one of the last available generators at a nearby Canadian Tire, she said in a recent interview.
It took four days for power to be restored, she said, while for others it took more than a week.
“I’m really not used to getting this type of snow as quickly as it came,” Bauer said.
Trying to predict the effects of climate change on winter conditions carries some uncertainty, meteorologists say.
Warmer lakes could mean more severe snowstorms. But as winters get warmer overall, it’s also possible that precipitation will increasingly appear as rain. Fluctuating temperatures could mean some heavy snowfall is followed by unseasonably warm weather, increasing the risk of winter flooding.
“In a nutshell, it’s a complex issue and it’s really kind of a foggy crystal ball into the future,” Ashton said.
A 2019 report by Canadian and American scientists suggests that the Great Lakes basin has experienced an increase in precipitation over the past century that has outpaced that of the rest of the United States, with most of it falling as rain. unusually heavy rain and snow events.
The Great Lakes entered one of their warmest periods in decades this winter, spurred in part by fallout from the naturally recurring El Niño climate cycle, which peaked last winter.
By early December 2024, four of the five lakes had warmer average surface temperatures during the first 11 months of the year than any over the past three decades, according to the National Oceanic and Atmospheric United States Administration.
Last winter, the lakes also had some of the lowest ice cover.
Intensifying lake-effect storms should give lakeside communities pause, said Rood, the climatologist.
“This should really motivate you to think about the question: ‘How can I handle future storms?’
That’s exactly what Gravenhurst officials are seeking to do. A municipality spokesperson said a debriefing meeting was planned for this month. A report is also being prepared for the city council on the cause of the storm and the local response.
Bauer said she was heartened to see neighbors supporting each other during the worst of times.
She remembers how someone in her area used a snowmobile to help rescue an elderly neighbor from her snowy home and then offered her a place to stay.
“You could see the community coming together.”
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