How to Survive a Tornado
Would you know what to do if faced with an oncoming tornado?
What is a tornado?
The Met Office describes a tornado (sometimes referred to as a twister) as a rapidly rotating column of air that reaches between the base of a storm cloud and the Earth’s surface.
Tornadoes form in very unsettled weather as part of severe thunderstorms. Particular conditions need to be present for a tornado to occur and the result is a violently whirling mass of air, known as a vortex, which forms beneath the storm cloud.
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.
Where do tornadoes occur?
Around 30 tornadoes are reported in the UK each year and they can cause structural damage if they pass over built-up areas. Fortunately, tornadoes in the UK tend to be small, short-lived events that rarely threaten life.
In the States, however, it can be a very different matter. ‘Tornado Alley’, a region of Central USA, is particularly prone to violent tornado outbreaks which can be deadly. In spring and summer, warm air from the Gulf of Mexico meets cool air from Canada in this region, leading to the formation of powerful storms known as supercells which, if the conditions are right, can spawn tornadoes.
What to do when faced with a Tornado
If you’re outdoors and a tornado is approaching then it’s best to seek shelter underground or inside a sturdy building. Once you’re inside a building, you want to get as low as you can, staying away from outside walls, doors and windows. Cover your head and upper body with whatever you have – that’s where you’re most vulnerable to being injured by flying and falling debris.
If it’s impossible to shelter in a building, get as low to the ground as possible. Find a ditch or ravine and lie flat, covering your head and upper body. Storms that cause tornadoes often come with very heavy rain, so be sure you’re not taking cover in a flood prone location. Hiding under a bridge or underpass may also seem a good idea, but meteorologists say that’s one of the worst things you can do. Such structures can amplify the speed of winds and offer little to no protection from flying debris. The best way to avoid having to make such life and death decisions in the moment, though, is to pay close attention to local weather forecasts before venturing out.
It may be human instinct to flee from danger, but it’s not advisable to try and outrun a tornado in a car as high-speed tornado winds can blow large objects, including vehicles, hundreds of feet.
If severe thunderstorms are forecast, reconsider your plans to be outside. Stay close to a safe shelter in case a tornado warning is issued for the area of the USA you are visiting.