Summer afternoon hailstorms are a part of life in Calgary.
It’s why a team of researchers from Ontario have installed a network of sophisticated weather stations across the city to study the storms that regularly pummel buildings and cars — sometimes causing tremendous damage.
The Northern Hail Project, a spinoff of the Northern Tornado Project, recently finished installing 19 state-of-the-art weather stations across Calgary, as well as one in Airdrie, just north of the city.
Julian Brimelow, the project’s executive director, said this is the only hail-focused network of research stations in Canada, among only a handful of others across the globe.
“They haven’t been out here very long, but they’ve already captured numerous hailstorms over Calgary,” he said. “The summer has been quite busy.”
The weather stations track all the basic weather data, such as temperature and wind speed, but they’re also equipped with disdrometers, which look like round metal plates, that use extremely sensitive microphones to record impacts from hailstones.
“It’s not interested in rain, it just records hail,” Brimelow said. “It also gives us an estimate of each of those impacts, how big the hail was.”
This ground-level information will be compared to radar data, allowing researchers to learn more about how hailstorms function, which could lead to better forecasting, more accurate warnings and less damage to homes, cars and crops across Canada.
Ultimately, Brimelow said, the group’s goal is to use this knowledge to help craft building codes that could create more resilient communities, designed to better withstand powerful hailstorms.
“Having these ground truth data is really important toward achieving that,” he said.
To learn about how damaging hail can be, the research group chases storms across Alberta’s “hail alley” to find the largest hailstones.
Hail alley, Brimelow explained, is a narrow band east of the Rocky Mountains, extending from northwest of Edmonton, along the foothills to south of Calgary.
Francis Lavigne-Theriault, a research associate for the Northern Hail Project, uses drones to capture high-resolution images of fallen hail immediately following a storm.
Last August, a team led by Lavigne-Theriaul found the largest hailstone recorded in Canadian history. It was near Markerville, Alta., roughly 130 kilometres north of Calgary,
The stone was 12 centimetres in diameter, larger than the span of a DVD disc, and weighed 292 grams, roughly the heft of a tennis racket.
Researchers keep the stone in a freezer at Western University. There, they make replicas of large hailstones to drop from drones to simulate fall speeds, a key factor in understanding the damage large hail can cause in severe storms.
More destructive hailstorms seen across the world
Joshua Soderholm, a research scientist from the Australian Bureau of Meteorology, is in Alberta this summer to test hail measurement devices alongside the Canadian researchers.
He says destructive hailstorms are becoming more common across the globe as increasingly warm and humid weather sets the stage for storms to produce larger, more destructive hail.
The devices Soderholm is testing in Alberta are shaped like small hailstones. Balloons drop them into storm clouds, where they float and swirl among the developing hail, measuring the conditions inside the storm.
“There is no other way to get this data,” Soderholm said, noting the devices can be reused once they drop out of the sky.
“For us, these devices are giving us new and exciting information on the conditions inside a thunderstorm, where hail is growing.”
In June 2020, the most costly hailstorm in Canada’s history struck northeast Calgary, resulting in roughly $1.4 billion in damage and 70,000 insurance claims.
According to Brimelow, one such billion-dollar storm happens across the globe every year. But with climate change, the conditions become more likely for severe storms to develop on steamy summer days in Alberta’s hail alley.
“The insured losses from hail have been increasing dramatically across the world,” he said. “We started seeing evidence of that in the U.S., but now we’re seeing it increasing in too many places to be a coincidence. We’re seeing trends in Europe, Australia and now in Canada.”
The Northern Hail Project hopes to have Calgary’s weather station network in place for at least a few years. Data from the stations is recorded in real-time and sent via the cell network to a server in Ontario every 10 minutes.
The research team is developing a portal so the public can view the data.