Here are some interesting facts about tornadoes.
- A tornado is a narrow and rotating column of air, which touches the ground as it moves. Also known as twisters, these columns can cause loss of life and terrible damage.
- A tornado is often caused by two different air masses meeting, such as warm and cold air. Winds blowing from different direction can also cause the air to rotate.
- Most tornadoes are less than 70 metres across, although they can be several km across. They can reach wind speeds of almost 500 kmh in extreme cases, although the average speed is about 170 kmh.
- Every continent except Antarctica has experienced tornadoes, although they occur mostly in Tornado Alley in the USA. This large area includes the states of Nebraska, Oklahoma, Kansas and parts of Texas.
- The deadliest tornado occurred in Bangladesh in 1989, killing about 1,300 people. Over a dozen tornadoes in Bangladesh have each killed over 100 people.
- One of the deadliest in America was in the Midwest in 1925. The twister lasted for several hours, travelled a distance of 350 km and killed almost 700 people.
- A tornado can form at any time of day, although most likely between 3pm and 9pm. March to May is the most common time of year for tornadoes in the southern US.
- Tornadoes rotate clockwise in the southern hemisphere and anti-clockwise in the northern hemisphere. They have been described as sounding like a train, a jet engine or a waterfall.
- They are almost invisible until the rotating wind picks up debris and dust, making them visible. Tornadoes can appear red or white if the wind picks up clay or snow from the ground.Tornadoes are so powerful that they can pick up animals, people and cars and carry them for several hundred metres.
- In the event of a tornado, a basement or inside room is the safest place.
