What is a Tornado?

When you think of weather in Canada, what do you think of? In many provinces and territories, you might think of cold winters. In big inland cities, you might think of summer heat. If you live near an ocean, you might think of rain, drizzle and fog.

But did you know that Canada is one of the most tornado-prone countries in the world? An average of 62 tornadoes hit Canada every year!

Let’s look at how a tornado forms, and what parts of Canada are most likely to experience one.

How does a tornado form? 

According to Environment Canada, a tornado is a rotating column made up of high winds. You can recognize a tornado from its funnel-like shape.

Usually, a tornado begins with an extremely large type of thunderstorm, called a supercell storm. However, for a tornado to form, some other very specific weather conditions are required. First, warm air has to rise toward the storm clouds. As this air rises, it gains speed, creating an updraft. As more air is swept into the updraft, it can change direction and gain speed. The updraft also carries moisture toward the clouds. The clouds can retain this moisture and use it later to fuel the tornado. 

If all of these conditions occur, a vortex (spinning air) forms within the storm. This vortex is called a mesocyclone, and it looks like a funnel-shaped cloud. Cool, dry air wraps around the mesocyclone, creating a downdraft. This results in a vast temperature difference between the inside and outside of the mesocyclone. The bottom portion of the mesocyclone will narrow, causing the winds to spin faster. From there, the mesocyclone sinks within the storm. If it reaches the moisture that was previously retained within the storm cloud, the moisture will become sucked into the funnel. This gives the mesocyclone the fuel it needs to become the massive rotating wall of clouds that we call a tornado!

Tornadoes can be very violent. This is due to their extremely high rotating wind speeds. The speed of the wind in a tornado can range from 180 km/h to 400 km/h. How fast is that? Well, on most highways in Canada, you can only drive 100 km/h. Tornadoes move a lot faster than that!

Where do tornadoes happen?

In Canada, tornadoes are often caused by warm air travelling up from the United States. There are two main areas of Canada that are most likely to experience tornadoes. One ranges from the Prairies in Alberta all the way to Lake Superior in Ontario. The other area covers southern Ontario and southern Quebec. Some scientists think that central British Columbia may also be tornado-prone. 

In the United States, tornadoes are often caused by cold air travelling down from Canada. This happens in the Great Plains region, which covers North Texas, Oklahoma, Kansas and Nebraska. This area gets so many tornadoes that the media has nicknamed it Tornado Alley!

Did you know?

In Canada and the United States, tornado strength is measured using the Enhanced Fujita scale, or EF scale. It ranks tornadoes from 0 (little damage) to 5 (massive damage). 

Most tornadoes last between 10 and 40 minutes. But they can cause enormous damage in that amount of time. They can flip cars over. They can destroy houses. They can even pull trees right out of the ground!

Did you know?

Canada’s most destructive tornado struck Regina, Saskatchewan in 1912. Dubbed the “Regina Cyclone”, it killed 28 people, injured another 300 and destroyed the homes of a quarter of the city’s residents!

How do you know if a tornado is coming? What should you do about it?

There are several ways to tell if a tornado is on its way. A funnel cloud is the most obvious sign. But severe thunderstorms, especially ones that darken the sky, could also be a warning. Sometimes you’ll hear a rumbling or whistling in the air before a tornado strikes.  

To know for sure, tune into your local radio station. You can also check with Environment Canada, the department responsible for monitoring weather and issuing tornado warnings. 

If you suspect that a tornado is coming your way, get inside. Get as far as you can from any windows—they may break!  Basements and ground-floor bathtubs are good places to wait out the storm.

What is a storm chaser?

Not everyone hides when a tornado is coming. People called storm chasers actually go out and try to get in a tornado’s path! Sounds like an adventure, doesn’t it? Storm chasers may love the thrill of the chase, but they also have bigger goals. They aim to eventually be able to predict when and where tornadoes will strike. To achieve this goal, they use special tools to measure tornadoes. 

Storm chasers are often the first to know when a tornado is on its way. They’re sometimes the first ones to inform Environment Canada and its American equivalent. They are also often on the scene to help out when tornadoes cause big trouble. 

Many storm chasers do it as a hobby. But some people make a living out of it.