While not nearly the storm of the century, a severe weather event on Aug. 1 in central Alberta produced a Canadian record-breaking hailstone. And a field team from Western’s newly formed Northern Hail Project (NHP) chased it down and brought it home.
The NHP field team, led by engineering research assistant Francis Lavigne-Theriault, followed the storm to Markerville, Alta. (about 35 kilometres southwest of Red Deer) and found several baseball-sized hailstones. Further south and approximately 20 minutes after the storm had passed (6:14 pm MDT), under a tree canopy, they recovered several larger hailstones, many of which were grapefruit to softball-size including the record breaker.
Weighing 292.71 grams, the record breaker eclipses the previous title holder – which weighed 290 grams and was collected nearly 50 years ago in Cedoux, Sask. on July 31, 1973. With a diameter of 123 millimetres, the hailstone has a slightly larger span than a standard DVD (120 mm).
Lavigne-Theriault and the team ultimately collected seven bags at the Markerville location, all of which are baseball-sized hail or larger (at least 70 millimetres or 2.75 inches in diameter). The samples are currently being stored in a freezer and Western researchers will soon study the ice cores of the large hailstones to better understand their internal structure and chemical composition.
They will also be studying the aerodynamics of large hailstone replicas, by dropping them from drones and studying how they fall. This will help establish what their terminal fall speeds are, which is important because this is a strong determining factor as to how much damage they cause. The irregular shapes of these large hailstones mean that there can be quite a lot of variation, which they are also investigating.
NHP is a research spinoff of the Northern Tornadoes Project, which was founded in 2017 as a partnership between Western and ImpactWX.
Did you ever imagine you would find Canada’s biggest hailstone when you headed out to Alberta in the spring for the first season of NHP? 
No! I didn’t know what to expect; I had never chased in Alberta before. However, I did have a lot of forecasting knowledge of the area having lived in the prairie provinces for several years and I have a lot of chasing experience in Colorado and the U.S. high plains region, which has similar climatology to Alberta. So, I certainly knew that big things were possible in Alberta.
When you are storm chasing, is your heart racing or are you the proverbial calm before the storm?
Next year (2023) will be my tenth as a storm chaser, so I would like to think I am calm, but you would have to ask my coworkers to be sure (laughs). There is a saying, when storms become really intense you shift into “storm chasing mode,” and this usually means a heightened focus and acute situational awareness, which comes from years of field experience in some of the most intense storms in the world. In those moments, I am centred, calm and focused on the mission, but my heart starts racing when we find very large hailstones on the ground (laughs).
Hail is frozen precipitation, so did the fact your record-breaking discovery could melt make your heart race too?
My heart races more when I’m trying to avoid falling hail, which can damage your vehicle. I was able to position the field team in a way that we always avoided hail cores and were very safe; that way our decision-making wasn’t done in haste. We did get some big adrenaline rushes when we were trying to install probes before the storm started, especially in treed areas with reduced visibility and with little cellphone service, and this mainly came from the fact that we were attempting something that hadn’t been done before in hail research in Canada.
Endnotes 2022
This story is part of our Endnotes 2022 series which showcases the people behind some of the year’s most compelling Western stories.
