Researchers chase storms, study fist-sized stones in Alberta's ‘Hailstorm Alley'

CTV News

22-07-2025

Julian Brimelow, executive director of the Northern Hail Project, displays a 3D replica of a near record hailstone collected in 2022, at the Telus Spark Science Centre in Calgary, on Tuesday, July 22, 2025. (THE CANADIAN PRESS/Bill Graveland)
Julian Brimelow holds up a replica of the mother of all hailstones – a lumpy white blob as big as your fist carrying the weight of two baseballs with the power to pulverize fields of corn into green-yellow mush.
Brimelow and other researchers from Western University in London, Ont., are using it in their research to better understand and predict Alberta's prevalent hailstorm activity and mitigate harm to people and property.
Hail can be bad across the Prairies. But Brimelow says when it hits in Alberta, it hits hard.
'It's much worse than I thought it could be in terms of damage potential,' Brimelow said Tuesday at the project's open house at the Telus Spark Science Centre.
'On the same day as the (2024) Calgary hailstorm, there was a storm farther south and that decimated six to seven-foot corn crops to the point that our team wasn't sure it was actually corn,' he said.
'It was that pummeled into the ground.'
'Hailstorm Alley' runs from High River, just south of Calgary, north to central Alberta. The area sees more than 40 hailstorms every summer, causing hundreds of millions of dollars in damage.
Brimelow, executive director of the Northern Hail Project — a branch of Western University's Canadian Severe Storms Laboratory — said it's probably the most active hailstorm zone in Canada.
A storm in Calgary last August brought significant hail, strong winds, heavy rain and localized flooding, affecting about one in five homes. The Insurance Bureau of Canada estimated the damage to the city, deemed the country's second-costliest weather-related disaster, at $2.8 billion.
Hailstones as big as golf balls hammered the tarmac at Calgary International Airport, damaging planes at WestJet and Flair Airlines and forcing them to ground 10 per cent of their fleets for repairs and inspections.
Brimelow said such hailstorms are underestimated at one's peril. Several small animals and pets were killed in Calgary last year, he said, and an infant was killed in Europe in 2023.
The research sees stones collected on scene, preserved in a mobile freezer, and later measured, weighed, photographed and perhaps replicated.
'The more interesting stones we'll 3D scan and then we can make prints,' he said.
Copies of several realistic hailstones were on display at the open house, ranging in size from a walnut to a golf ball and one bigger than a large hand.
'This is the new record-sized Canadian stone. This fell in 2022 near Innisfail,' Brimelow said. 'This is 12.3 centimetres across and nearly weighs 300 grams. This would have been falling at 160-plus kilometres an hour.'
The team's field co-ordinator, Jack Hamilton, said the size and shape of the stones provide researchers with information on what happens inside the storms.
'It was long thought that the hailstone sort of goes through the storm in a washing machine cycle. But we're actually learning that it's probably just once, maybe twice, that the hailstone goes through the storm and it collects all of its mass in that one travel through,' Hamilton said.
'It gets bigger and bigger, and eventually gravity takes over and it falls. And it falls pretty fast.'
To get the stones, they first have to chase them.
Hamilton said their chase vehicles have a protective coating against hail and are equipped with storm-locating radar and a lightning detector for safety.
'Our primary objective is to collect as much data as we possibly can,' he said. 'We go in behind these storms, and we collect the hail that falls behind it.'
This report by The Canadian Press was first published July 22, 2025.
Bill Graveland, The Canadian Press