Willy-Willy is

The term “Willy‑Willy” is an Australian regional name for tropical cyclones (hurricanes/typhoons), specifically applied to strong cyclonic disturbances affecting north‑western and Western Australia. Texts describe willy‑willies as the local designation for hurricanes/tropical cyclones visiting the north‑west coast and Western Australia during the summer months, and classify them alongside other regional names for tropical cyclones (hurricanes, typhoons, cyclones) used elsewhere in the world [3]. Therefore, the option identifying Willy‑Willy as a tropical cyclone of north‑west Australia is correct.

Sources

1. [1] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 14: Climate > Cyclonic Activity > p. 142
2. [2] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 9: Atmospheric Circulation and Weather Systems > Tropical Cyclones > p. 83
3. [3] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 8: Natural Hazards and Disaster Management > Tropical Cyclones > p. 46