Explanation:

Tropical cyclones are known by different names in different parts of the world. In Western Australia, they are commonly known as Willy-Willies. Here's why:

What is a tropical cyclone?
A tropical cyclone is a large, rotating storm system that forms over warm ocean waters. They are known by different names depending on the region they occur in. In the Atlantic and Northeast Pacific, they are called hurricanes, in the Northwest Pacific they are called typhoons, and in the South Pacific and Indian Ocean, they are known as cyclones.

Why are they called Willy-Willies?
The term Willy-Willy is derived from an Aboriginal language in Western Australia. The term refers to a whirlwind or dust devil, which is a small-scale version of a tropical cyclone. These dust devils are a common occurrence in the arid regions of Australia, and they often form in the wake of thunderstorms.

What is the impact of Willy-Willies?
Willy-Willies are generally not as severe as tropical cyclones, but they can still cause damage to property and infrastructure. They are also a hazard to aviation, as they can cause turbulence and damage to aircraft.

Conclusion:
In summary, tropical cyclones are known as Willy-Willies in Western Australia due to the prevalence of small-scale whirlwinds in the region. While they are not as severe as full-blown tropical cyclones, Willy-Willies can still cause damage and pose a hazard to aviation.