Climate change means Alberta could see more large hail events in the future. Here's why

CBC Alberta and Saskatchewan have teamed up for a new pilot series on weather and climate change on the Prairies. Meteorologist Christy Climenhaga will bring her expert voice to the conversation to help explain weather phenomena and climate change and how it impacts everyday life.

Southern Alberta lived up to its nickname of Canada's "hail alley" this week when an intense thunderstorm brought down hail the size of softballs, shattering windows and denting roofs of dozens of vehicles on the QEII near Red Deer Monday,

And while large hail events are not uncommon in the province, experts warn that severe storms producing large hail could happen more frequently because of climate change.

But how does hail get so big, and why are these sorts of storms more likely in the future?

Hail can happen in many different types of thunderstorms, but they need specific conditions to grow.

Hail is formed when water droplets are lifted high in the sky by updrafts associated with strong thunderstorms. 

When they are lifted high enough they will freeze, and grow in size as they collide with more droplets. 

When they get large and heavy enough that the thunderstorm's updrafts can't support it, they will fall. The longer the hail remains in that cold part of the thunderstorm cloud, the larger they will grow.

Jesse Wagar, a meteorologist with Environment and Climate Change Canada, says that for these very large hailstones you need more than just your typical thunderstorm. 

"These storms that produced this significantly large hail, those are supercell thunderstorms, which are required in order to get hail to to reach the sizes that they did," says Wagar.

Supercell thunderstorms have what is called a mesocyclone within the thunderstorm cloud. 

It's a powerful rotating updraft that allows hailstones to remain aloft longer and get larger. 

Wagar says besides the power of the thunderstorm, things like moisture at lower- and mid-levels of the atmosphere and freezing levels, or how high you have to go for temperatures to approach zero, are all important elements as well. 

Wagar says that once the hailstone starts fall and passes into the lower part of the cloud, it will start to melt