Tornado Preparation
What is a tornado?
A tornado is a violent windstorm characterized by a twisting, funnel-shaped cloud. It is spawned by a thunderstorm (or sometimes as a result of a hurricane) and produced when cool air overrides a layer of warm air, forcing the warm air to rise rapidly. The damage from a tornado is a result of the high wind velocity and wind-blown debris.
Tornado season is generally May through September, although tornadoes can occur at any time of year. Tornadoes in Alberta tend to occur between 5:00 p.m. and 7:00 p.m.
Why are tornadoes a problem in Alberta?
Canada is ranked second in the world for frequency of tornadoes, behind the United States.
Alberta has been hit by 268 tornadoes in the last 17 years, averaging about 16 tornadoes per year. One tornado in every 3-4 years is classified as “strong,” and one in every 30 to 50 years is classified as “violent.”
Some of the worst tornadoes to hit Alberta include:
Pine Lake, Alberta - July 14, 2000. A strong tornado hit a campground at 300km per hour, causing 12 fatalities and injuring more than 140. As a result of the tornado, 450 people were left homeless and close to 1000 people were displaced due to damaged recreational vehicles. This was the 4th deadliest tornado to hit Canada.
Edmonton, Alberta - July 31, 1987. This tornado killed 27 people, destroyed more than 300 homes, and resulted in $350 million in damage, of which only $250 million was insured. The loss of life, injuries and destruction of property made it the worst natural disaster in Alberta's recent history, and one of the worst in Canada's history.
Tornado Danger Signs
- Learning these tornado danger signs could be the difference between life and death.
- Be aware of dark, often greenish sky; large hail; wall cloud; or a loud roar, similar to a freight train.
- An approaching cloud of debris can mark the location of a tornado even if a funnel is not visible.
- Before a tornado hits, the wind may die down, and the air may become very still.
- Tornadoes generally occur near the trailing edge of a thunderstorm. It is not uncommon to see clear, sunlit skies behind a tornado.
- Tornadoes often travel from the southwest heading northeast.
What do I do during a tornado?
If at home:
- Get away from windows.
- Go at once to a windowless interior room, storm cellar, basement, or lowest level of the building.
- If there is no basement, go to an inner hallway or a smaller inner room without windows, such as a bathroom or closet.
- Go to the center of the room. Stay away from corners because they tend to attract debris.
- Get under a piece of sturdy furniture such as a workbench or heavy table or desk and hold on to it.
- Use arms to protect head and neck.
- If in a mobile home, get out and find shelter elsewhere.
If at work or school:
- Go to the basement or to an inside hallway at the lowest level.
- Avoid places with wide-span roofs such as auditoriums, cafeterias, large hallways, or shopping malls.
- Get under a piece of sturdy furniture such as a workbench or heavy table or desk and hold on to it.
- Use arms to protect head and neck.
If outdoors:
- If possible, get inside a building.
- If shelter is not available or there is no time to get indoors, lie in a ditch or low-lying area or crouch near a strong building. Be aware of the potential for flooding.
- Use arms to protect head and neck.
If in a car:
- Never try to out drive a tornado in a car or truck. Tornadoes can change direction quickly and can lift up a car or truck and toss it through the air.
- Get out of the car immediately and take shelter in a nearby building.
- If there is no time to get indoors, get out of the car and lie in a ditch or low-lying area away from the vehicle. Be aware of the potential for flooding.
- Do not try to drive to an underpass.
Sources include:
- Alberta Municipal Affairs, Disaster Services
- U.S. Federal Emergency Management Agency
- Emergency Preparedness Canada
- Catastrophic Loss Institute
- Insurance Bureau of Canada