‘Twisters’ and ‘Wicked’, two of the highest grossing films of 2024, both feature the meteorological phenomenon of tornadoes. Unfortunately, these highly dangerous forms of extreme weather are not mere works of fiction and wreak havoc worldwide on a regular basis. 

More colloquially referred to as ‘twisters’, tornadoes are rapidly rotating columns of air that extend from storm clouds down towards the ground. For these columns to occur, particular atmospheric conditions must be present. National Geographic summarises these conditions as: “warm, moist air”; “an unstable atmosphere” and “winds at different levels moving in different directions at different speeds” (wind shear). When all three conditions arise simultaneously, a supercell thunderstorm (a thunderstorm capable of producing tornadoes) will occur.  

No two tornadoes are exactly alike; they can differ dramatically in both size and speed. Tornadoes range in width from a few yards to over 3km; can reach around 20km in height; and vary in speed from only a few mph, to over 200mph. The larger a tornado is, and the higher its wind speed, the more potential it has to cause damage. In built up, densely populated areas and in areas with fewer precautions in place (such as underground storm shelters) the amount of damage caused by a tornado will be greater. For instance, the costliest tornado was the 2011 event in Joplin, Missouri, which caused an estimated $2.8 billion worth of damage. Whilst this tornado was not the most powerful on record, it caused immense damage, affecting around 7,500 residences, 500 businesses and over 15,000 vehicles, because it occurred in a built up area. 

The variation in tornadoes’ wind speed and expected damage is encapsulated in multiple tornado scaling systems. In the US, the Enhanced Fujita Scale has been utilised since 2007. This scale categorises tornadoes from EF0 (tornadoes with winds of 65-85mph that are expected to cause minor damage), through to EF5 (tornadoes with wind speeds exceeding 200mph that are expected to cause incredible damage). Here in the UK, the TORRO Tornado Intensity Scale has been used since 1972, and includes a greater range of categories (from T0 through to T10) to divide up tornadoes based on their wind speed and expected damage.

When considering areas impacted by tornadoes, it is likely that the US springs to mind. Indeed, the US is the country that receives the most tornadoes each year (1,225 on average, with 1,197 recorded in 2023, costing the US a sum estimated to be in excess of $1.3 million). They most commonly occur in a loosely defined region in the centre of the country, referred to as ‘Tornado Alley’. Tornado Alley spans sections of numerous central states, including Oklahoma, Kansas, and the state that receives the most tornadoes each year: Texas (where over 150 tornadoes were recorded in 2024 alone). The region is particularly affected by tornadoes because it commonly experiences the culmination of the three necessary atmospheric conditions. However, Tornado Alley is not the only area of the US that experiences tornadoes; tornadoes have been recorded in each of the 50 states. Furthermore, tornadoes are not confined to the US. Each year, tornadoes affect individuals and landscapes worldwide. Even the UK receives 30 tornadoes on average each year (although, these tornadoes are often fairly weak, with around 95% being classified as T0 or T1 on the TORRO Tornado Intensity Scale). 

Concerningly, the destructive impact of tornadoes could be set to increase as a result of climate change. Studies have predicted that climate change could enable the formation of more serious thunderstorms. However, this would not guarantee the formation of more tornadoes, as the three essential atmospheric conditions must also be present for a supercell thunderstorm (with tornado-potential). One of these conditions (atmospheric instability) is anticipated to increase as a result of climate change. However, wind shear is expected to decrease. Changes have already been identified in the trends of tornado events, with events becoming more clustered, but this contradiction in how climate change influences the conditions necessary for tornado formation means that it is currently impossible for climate scientists to accurately predict what the future will hold. One can only hope that there will be a reduction in these destructive weather events, and that they will become a phenomenon more common in fiction than in reality.