What Causes Tornadoes To Form? Why Are They Hard To Predict?

Tornadoes are difficult to predict and can lead to great destruction. While the reason behind their formation and the role of climate change in their formation are known, they are not always seen coming.

Tornado Formation Explained

In most cases, tornadoes are brief and harmless. However, if this weather event goes beyond the norm and ends up colliding with humans, it could lead to serious damage and even death.

While scientists are already familiar with tornadoes' basic ingredients, they are still trying to figure out the exact cause behind the phenomenon.

Nevertheless, it is known that tornadoes form in specific weather conditions. They usually begin with a type of rotating thunderstorm known as a supercell, which can bring strong winds, lightning, flash floods, and hail.

When wind speed and direction have differing altitudes, a wind shear may result. While wind shears are usually harmless, they can make air currents spin and create a horizontal air tube. This is common in supercell thunderstorms but is not yet considered a tornado.

At times, a storm may suck up that air tube until it turns vertical. When this takes place, it becomes known as a mesocyclone, which is still not a tornado.

For tornado formation, it is necessary for spinning air to be present close to the ground. The greater the strength of the air tube's rotation, the closer it may reach the ground and the likelier it will be to become a tornado.

Atmospheric scientist Walker Ashley from Northern Illinois University likens this situation to that of a figure skater. Ashley explains that when a figure skater extends their arms, they end up slowing down. When they bring their arms within, they end up speeding up. In the case of a storm, it takes this rotation, tilts the rotation to become vertical, and stretches it. When the stretch happens, the rotation gets increased even more.

When this happens, warm air gusts rise while cool air gusts sink, blowing through the land. If the sinking and rising gusts are enough, the air close to the ground begins to spin.

When it is vertical, the tornado gets darker. It picks up debris, dust, and anything else that happens to be in its way. An incredibly intense tornado could end up picking up animals, cars, and even houses.

Why Tornadoes Are Difficult To Predict

In the US, spring is considered the season of tornadoes. However, these weather events can still take place at any time. They are notably difficult to predict because, when compared to other kinds of extreme weather events, tornadoes are quite small. This makes them difficult to observe.

Ashley explains that when different hazards, such as droughts, floods, and hurricanes, are thought about, tornadoes could be one of the smallest kinds. In fact, the strongest and most violent tornadoes will not exceed 800 meters in width. They typically happen in seconds or minutes.

With this, tornadoes tend to take place below the levels that researchers typically use for weather event observation, modeling, and prediction. Ashley explains that, though scientists are capable of simulating tornadoes on computers, it would take great computing power to do so.

Hence, in order to issue a warning, scientists search for supercell thunderstorms and make use of radar technology to gauge the rotation speed of the mesocyclone. A faster rotation and great proximity to the ground could indicate a higher likelihood of the weather event turning into a tornado.

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