Hail in Ontario? Nope! Why showers produced ice this week
Southern Ontario was hit with multiple rounds of what appeared to be hail this week, but it has a whole other name for it.
Appearances can be deceiving.
What looks, feels, and even sounds like hail isn’t actually hail. It’s graupel.
Over the past few days, a stormy pattern set up across southern Ontario, with isolated showers and thundershowers in some locales. Among the storm reports were photos and videos of ice, something that resembled hail. In reality, what you saw was actually graupel.
In meteorological terms, a pesky, closed upper-level low stalled out over the region. This brought cold air aloft down to the surface through convection with some strong winds, which were contributing factors in why we saw graupel.
There’s a difference between how hail and graupel both form.
Hail is a type of icy precipitation that occurs in thunderstorms. Strong updrafts within a thunderstorm carry moisture to the top of the cumulonimbus cloud, where the moisture freezes into ice. This process continues until the hailstone becomes heavy enough that gravity takes over and it falls from the cloud.
Graupel are soft, small pellets created when supercooled water droplets freeze on a snowflake. As the snowflake begins to fall out of the cloud, it gets caught in an updraft and undergoes a process called riming. Supercooled droplets, which are essentially water droplets that are colder than the freezing mark, collect and freeze on the snowflake, creating a soft snow pellet we know as graupel.
It didn’t take long for people to post photos of what they thought was hail, as they may not have been expecting to see graupel. Below is a selection of visuals currently making the rounds on social media.
Thumbnail courtesy of Scott Stewart in Stratford, Ontario
