Imagine living in a part of the Prairies where a single hailstorm can cause $500 million in damage. Farmers and residents of High River Lacombe and west of Rocky Mountain House don’t have to imagine. (It’s a region that starts just 65 kilometres south of Calgary and spreads north 175 kilometres and northwest 160 kilometres.) They live in an area affectionately known as “Hailstorm Alley.��?
This Albertan hail region is actually one of the worst in the world for hail with ice lumps that can easily cause $500 million in damage or more in just one hailstorm. To combat the rising damage costs insurance companies formed the Alberta Severe Weather Management Society (ASWMS) back in 1996. The mandate of the ASWMS was to create a Weather Modification system known as the Alberta Hail Suppression Project (AHSP). This $2-million operation functions 24 hours a day seven days a week from June 1 to September 15 every year. It uses specially modified planes that fly into storms and spray a chemical into the clouds to reduce the size of the hail which reduces damage to crops and personal belongings on the ground.
The planes typically fly and seed in an area known as Hailstorm Alley which runs along the foothills from the west of High River all the way to Rocky Mountain House Alta. The seeding airplanes will follow the bigger storms that move off the foothills and threaten communities and property in populated areas—a situation that happens every year when these planes fly above Calgary in an effort to protect homes cars and businesses from serious hail damage. Priority is assigned to storms depending on their severity and the size of the community being threatened and only those storms threatening populated areas are seeded.
By seeding these planes are able to treat young cloud turrets—small towers of clouds—before they grow into large mature thunderstorms that produce hail. This essentially stops large destructive hail from forming but allows smaller pellets to fall thereby allowing nature to produce thunderstorms which are necessary forms of precipitation.
The good news is that seeding thunderstorms isn’t damaging to health or the environment. The chemical used known as silver iodide is non-toxic in the dosage used to seed clouds. The average seeding rates are about 10 grams per minute —the equivalent to putting a spoonful of silver iodide over the Niagara Falls every minute according to Public Safety Canada.
The aim is to reduce the size and severity of hail storms and their success is the reduction in home insurance claims due to hail damage. At present there’s been a 50% reduction since the inception of AHSP which amounts to millions of dollars saved each year in hail damage.