Tornadoes form suddenly, are often preceded by warm, humid weather, and are always produced by thunderstorms.

Tornado warning signs include the following:

  • An extremely dark sky, sometimes highlighted by green or yellow clouds
  • A rumbling or whistling sound
  • A funnel cloud at the rear base of a thundercloud, often behind a curtain of heavy rain or hail.

Tornadoes are violent wind storms characterized by a twisting, funnel-shaped cloud which forms at the base of cloud banks and points towards the ground. Tornadoes usually move over the ground at anywhere from 20 to 90 kilometres per hour and often travel from the southwest to the northeast. They are erratic and can change course suddenly. Do not follow tornadoes in your car or attempt to take photographs of them – if you see a tornado, take shelter immediately.

Taking shelter during a tornado

  • If you are at home, go to the basement or take shelter in a small interior ground floor room such as a bathroom, closet or hallway. Failing that, protect yourself by taking shelter under a heavy table or desk. In all cases, stay away from windows, outside walls and doors.
  • If your are in an office or an apartment building, take shelter in an inner hallway or room, ideally in the basement or on the ground floor. Do not use the elevator and stay away from windows. Avoid buildings such as gymnasiums, churches and auditoriums with wide span roofs. These roofs do not have supports in the middle and may collapse if a tornado hits them. If you are in one of these types of buildings, take cover under a heavy table or desk.
  • If you are caught outside, lie flat in a ditch or other low-lying area and cover your head. If lightning is occurring, crouch in the leapfrog position and lower your head.
  • Do not get caught in a car or a mobile home – More than 50% of all deaths caused by tornadoes happen in mobile homes. If you cannot take shelter in a sturdy building, lie down in a ditch away from your car or mobile home. Hug the ground, protect your head and watch out for flying debris. Small objects such as sticks and straws can become lethal weapons when driven by the high winds created by tornadoes.


More information about Tornadoes