Calgary has a major ice problem, and it has nothing to do with hockey.
If you live in southern Alberta, you already know the drill. Every summer, the sky turns an eerie shade of bruised purple, the wind picks up, and suddenly your roof, your car, and your backyard deck are being pulverized by chunks of ice falling from the stratosphere.
It is loud. It is terrifying. And it is incredibly expensive.
For most people, a severe hailstorm is a cue to run for cover and pray their insurance policy is up to date. But for Julian Brimelow and his team at the Northern Hail Project (NHP), these storms are a massive, live-action scientific experiment. The NHP, which runs under the Canadian Severe Storms Laboratory at Western University, has spent years treating Alberta’s notorious "Hailstorm Alley" as their personal testing ground.
Honestly, there is no better place on Earth to do this work. Calgary is uniquely situated for some of the most violent weather in North America, and understanding why this happens is the first step toward stopping the multi-billion-dollar damage bills that pile up every single summer.
Why Calgary Keeps Getting Pummeled by Ice
To understand why Calgary gets hit so hard, you have to look at the geography. The city sits right in the shadow of the Rocky Mountains.
That mountain range does not just look pretty on postcards. It acts as a massive atmospheric ramp.
When moist, warm air blows in from the east and south, it hits the foothills and has nowhere to go but up. As this warm air is forced upward, it cools rapidly. At the same time, strong winds screaming over the mountains create what meteorologists call wind shear—a change in wind speed and direction with height.
This wind shear organizes messy thunderstorms into highly structured, rotating supercells. These are the monster storms that act as literal factory lines for giant hailstones.
Calgary is basically a sitting duck. It is a rapidly expanding, densely populated urban area built right in the middle of a natural storm highway. When a massive hailstorm rolls off the foothills, it does not just hit empty farmland. It hits suburban neighborhoods with thousands of vinyl-sided houses, paved driveways, and parked cars.
The numbers are staggering. On August 5, 2024, a single hailstorm ripped through northern Calgary, shredding siding, smashing windows, and forcing airlines to ground a huge chunk of their fleets at the local airport. That storm alone caused over $3 billion in insured losses, making it the second costliest natural disaster in Canadian history. The only thing worse was the 2016 Fort McMurray wildfire.
When you realize that Calgary also experienced a $1.2 billion hail disaster in 2020, you start to see the pattern. This is not a once-in-a-generation fluke. It is an annual threat.
The Myth of the Atmospheric Washing Machine
For decades, textbooks taught us a very specific story about how hail forms. You might remember this from school. The theory was that a tiny frozen droplet gets carried up by a storm’s updraft, freezes, falls back down, picks up a new layer of water, and gets thrown back up to freeze again.
People called it the washing machine cycle.
But actual field observations by researchers like Jack Hamilton, the NHP’s field coordinator, are flipping that old model on its head.
It turns out that most hailstones do not go up and down in a loop. Instead, they make a single, continuous journey.
A hailstone starts as a small ice embryo. As it rides the massive, powerful updraft of a supercell, it sweeps through a region of the cloud filled with supercooled water droplets—water that is way below freezing but remains liquid because it lacks a seed to freeze around.
As the ice embryo travels through this wet zone, it collects these liquid droplets like a snowball rolling down a hill. They freeze instantly to its surface, building up layers of ice in a single, incredibly fast pass.
Eventually, the stone grows so heavy that the storm's updraft can no longer support its weight. Gravity wins. The stone plunges toward the earth, accelerating as it falls.
If the stone is big enough, it can fall at speeds exceeding 160 kilometers per hour. When a piece of ice the size of a grapefruit hits a house or a car windshield at highway speeds, the results are devastating.
By analyzing the interior rings of actual collected hailstones, NHP scientists can read the storm's history, almost like counting the rings of a fallen tree. They can tell exactly how much moisture was in the cloud and how fast the updraft was moving. This physical data is gold. It helps us move away from computer-generated assumptions and closer to real, hard physics.
High Tech Gear Chasing High Velocity Ice
Chasing hailstorms is a lot harder than chasing tornadoes. With a tornado, you can sit a few miles away and take high-resolution video. With hail, you have to be right underneath the storm’s core to get the physical samples, which means putting yourself and your equipment directly in the line of fire.
The NHP team uses custom-built, armor-coated intercept vehicles designed to take a beating from falling ice. They do not just drive away from the storm; they drive right into the path of it, deploying specialized arrays of instruments directly in the storm's projected track.
Here is a breakdown of what they are using on the ground to collect data:
- Hail Swath intercept vehicles: Rugged vehicles equipped with protective mesh over the windshields, heavy-duty armor, and onboard radar to navigate the worst parts of the storm safely.
- Hail pads: Low-tech but incredibly reliable blocks of high-density foam wrapped in foil. When hail hits the pad, it leaves an imprint. By measuring the depth and diameter of the dents, researchers can calculate the exact size and kinetic energy of the falling stones.
- Automated hail catchers: Devices that channel falling hailstones straight into an onboard mobile freezer, preserving the physical stones before they can melt or sublimate. This lets researchers take them back to the lab for 3D scanning and structural analysis.
- Meso-networks of disdrometers: Calgary is home to a unique citywide network of 20 high-tech weather stations. These are not cheap backyard toys. They measure wind speed, wind direction, temperature, humidity, and even nearby lightning strikes in real-time.
The wind data is especially important. One of the biggest discoveries the NHP has made is that wind-driven hail is far more destructive than vertically falling hail.
When strong, localized winds push hail sideways, the kinetic energy increases dramatically. Instead of just hitting your shingles—which are designed to take a vertical impact—sideways hail smashes into vinyl siding, shatters double-paned windows, and rips through exterior insulation. It turns a bad storm into an absolute disaster.
The Radar Problem and Why We Need Ground Truth
You might wonder why we need people chasing storms with foam pads and freezers when we have multi-million-dollar weather radars scanning the sky.
The reality is that modern weather radar has a massive blind spot when it comes to hail.
Radar is fantastic at telling meteorologists if there is ice inside a storm cloud. It can spot the signature of frozen precipitation with high reliability.
What radar cannot do is tell you how big that ice is, or how much of it is falling.
A radar beam bouncing off millions of tiny pea-sized hailstones can look almost identical to a beam bouncing off a scattering of giant, golf-ball-sized stones. To a forecaster sitting in an office, both storms look dangerous, but one will dent your car while the other will completely destroy your roof and total your vehicle.
This is why "ground truth" data is so vital. By matching real-time radar data with actual physical measurements of hail collected on the ground, the NHP is helping to calibrate weather models.
The goal is to give forecasters the ability to issue highly specific warnings. Imagine receiving an alert on your phone that doesn't just say "severe thunderstorm warning," but instead warns you that "three-centimeter hail is expected to hit your neighborhood in fifteen minutes." That is the kind of warning that actually gives people enough time to pull their cars into the garage, bring their pets inside, and secure their property.
Surviving the Financial Storm
We cannot stop the mountains from forcing air upward, and we cannot stop supercells from forming. But we can change how we build our cities.
The massive damage payouts from the 2020 and 2024 storms are starting to make Calgary uninsurable for some residents. Insurance premiums are skyrocketing, and some companies are pulling back on coverage entirely. This is a quiet crisis that affects every homeowner in the region.
We need to stop building houses with materials that act like cheap plastic toys when hit by ice.
The data collected by the NHP is already being used to advocate for better building codes. Standard vinyl siding and cheap asphalt shingles are simply not fit for purpose in Hailstorm Alley.
We need to transition to impact-resistant roofing materials, class 4 shingles, polymer-modified asphalt, and fiber-cement siding. Yes, these materials cost more upfront. But when you compare that cost to the price of replacing your entire roof and siding twice in a single decade, the investment is a no-brainer.
Some municipalities in Alberta are starting to realize this, offering rebates for homeowners who install impact-resistant building materials. It is a start, but we need systemic change. Building codes must adapt to the physical reality of where we live.
What You Can Do Before the Next Storm Hits
While the scientists do their work in the field, there are immediate, practical steps you should take if you live in Calgary or the surrounding communities:
- Check your insurance policy today: Do not wait for the clouds to turn purple to find out what your deductible is for hail damage. Ask specifically about depreciation schedules on roofs; some policies will not pay for a full replacement if your shingles are over a certain age.
- Invest in impact-resistant materials: If you are replacing your roof or siding, do not opt for the cheapest materials. Look for Class 4 impact ratings. Many insurers offer premium discounts for homes built with these materials, which helps offset the upfront cost over time.
- Keep your trees trimmed: Weak, overhanging branches are the first things to snap when high winds and heavy hail hit, often causing secondary damage to windows and roofs. Keep them cut back from your house.
- Have a storm plan: Know where you can safely park your vehicles if a sudden storm hits while you are away from home. Identify local parkades or covered structures along your daily commute path.
The research coming out of the Northern Hail Project is proving that we do not have to be helpless victims of the local climate. By understanding the physics of these storms, we can build smarter, warn people faster, and protect our communities from the literal ice age that drops on our heads every single summer.
