While you might think tornadoes are rare occurrences in the UK, they do happen across the country.

The size of them and how much damage they cause can both vary but what does the Met Office say about tornadoes?

If you’re wondering what a tornado is, how big they can be and how many happen in the UK each year, then look no further.

What is a tornado?

A tornado is a column of air that rotates rapidly and reaches between the Earth’s surface and the base of a storm cloud, according to the Met Office website.

Very unsettled weather conditions help tornadoes form as part of severe thunderstorms but many conditions are needed for them to form.

The Met Office says that when the conditions occur, “a violently whirling mass of air, known as a vortex, forms beneath the storm cloud.”

The forecaster adds: “A funnel cloud usually develops as the vortex forms due to the reduced pressure in the vortex. Strong inflowing winds intensify, and the spin rate increases as the vortex stretches vertically.

“If it continues stretching and intensifying for long enough the vortex touches the ground, at which point it becomes classified as a tornado. The tornado then moves across the surface causing severe damage or destruction to objects in its path.

“A tornado typically has the form of a twisting funnel-shaped cloud between the cloud base and the ground. Sometimes the vortex can appear as a slender rope-like form, particularly when the tornado is weakening; sometimes a tornado can be almost invisible, observable by the debris thrown up from the surface.

“Tornadoes typically spin anticlockwise in the Northern Hemisphere (cyclonically).”

How big can tornadoes be and how long do they last?

The size and intensity of a tornado can vary but one would typically be between 20 to 100 metres wide at the surface.

A typical tornado would last for a few minutes and would have a track of about one mile.

Wind speeds typically range from 75 to 100 mph.

The Met Office adds: “The largest tornadoes are very rare occurrences. They can be over 2 miles (3.2 km) wide, track for over 60 miles (100 km) and have wind speeds in excess of 300 mph (480 km/h).

“A large, violent tornado passing through a populated area can lead to total destruction of buildings and property in its path and sometimes loss of life. Such large tornadoes are in the minority of occurrences.

“Most tornadoes, although they produce damaging winds, do not lead to the widespread devastation often associated with these weather events in the media. Tornado damage is localised; limited by the track of the tornado.”


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How many tornadoes happen in the UK each year?

While you might not have witnessed a tornado happen, they occur across the UK and the world each year.

They most often occur in North America but around 30 are reported in the UK every year.

The tornadoes that happen in the UK are usually small and short-lived but they can cause structural damage if they occur in built-up areas.