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Read about tornadoes, or click on the play button below to listen aloud.
A tornado is a column of air that is spinning very quickly. A tornado starts to form in a storm cloud. A spinning column of air starts to move down from the cloud. Before it touches the ground, the column of air is called a funnel cloud. When the funnel cloud touches the ground, it is called a tornado.
Tornadoes Are Powerful
A tornado can be one of the most dangerous storms in nature. Why? The wind in a powerful tornado is moving so quickly that it can destroy just about anything that gets in its way. In some tornadoes, the wind speed is over 300 km/h.
A powerful tornado can tear apart a house, send a car flying through the air, or lift a train car right off the train tracks. Less powerful tornadoes can still do a lot of damage. The wind can tear the roof off a house, snap large tree branches or even rip whole trees out of the ground. Falling trees and tree branches often damage homes and cars and sometimes injure people.
Tornadoes on the Move
A tornado does not stay in one place. Every tornado moves along with the cloud above it. Tornadoes move along the ground at different speeds. Some tornadoes move so slowly that they almost seem to stand still. A very fast tornado might move along the ground at about 100 km/h.
An average tornado travels at about 50 km/h. Most tornadoes last for a few seconds to a few minutes, but some last for over one hour.
You can see where a tornado has travelled because it leaves a path of damaged or destroyed buildings, trees, and ripped-up ground behind it.
Weather reports will tell you if a tornado watch is in effect in your area. This means that the weather conditions are right for a tornado to form, but a tornado has not yet been seen. If you hear there is a tornado warning in your area, you need to get to a safe place. A tornado warning means that a tornado has been seen and might pass through your area.
• Tornadoes are sometimes called “twisters.”
• Tornadoes were measured on a five-level scale that measures their wind speed and how much damage they do. Up to February 2007, tornadoes were measured on the F Scale or Fujita Scale (say it like this: Foo-jee-tuh), named after the Japanese scientist who created the scale. Tornadoes are now measured on the EF Scale or Enhanced Fujita Scale, which has higher wind speeds than the old scale.
• The strongest known tornado in Canada was in Elie, Manitoba, on June 22, 2007. That tornado was the only F5 tornado every recorded on the original Fujita Scale. The tornado lasted for 35 minutes, cut a path 300 metres wide, and travelled on the ground for 5.5 kilometres. Luckily, no one was killed or seriously injured but 19 homes were destroyed.
• The largest tornado outbreak in Canada occurred on August 20, 2009, when 19 tornadoes touched down in southern Ontario.
• An average of 60 tornadoes touch down across Canada every year. Out of those, 43 occur in Alberta and Saskatchewan, and 17 occur in Ontario and Québec.
• If you are caught outdoors or in a vehicle when a tornado is approaching, find a nearby ditch or a hollow in the ground, lie face down in it, and cover your head with your arms. Stay there until the tornado passes. Lying low like that, you are less likely to be picked up by a tornado and less likely to be hit by flying objects.
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1. What is a tornado?CorrectIncorrect
2. Match the definition to its term.
the column of air before it touches the ground
the column of air that touches the ground, sometimes called “twisters.”
3. True or false? Tornadoes stay in one place.CorrectIncorrect
4.What does it mean if a tornado watch is in effect in your area?CorrectIncorrect
5.How are tornadoes today measured?CorrectIncorrect
6. Where did the strongest known tornado in Canada occur?CorrectIncorrect