Intensification continued up until landfall, by which time Helen had attained Category 2 status on the Australian tropical cyclone intensity scale.
John reached peak intensity on 14 December as a Category 5 cyclone on the Australian cyclone scale, the highest rating possible.
Both warning centres use the Australian tropical cyclone intensity scale, which measures tropical cyclones using a six category system.
It includes their intensity on the Australian tropical cyclone intensity scale, duration, name, areas affected, deaths, and damages.
After forming over the Arafura Sea, the Tracy moved south and hit the city with Category 4 winds on the Australian cyclone scale.
After receiving the name Clare on 7 January, the system ultimately peaked at Category 3 intensity on the Australian tropical cyclone scale.
This made Clare a Category 3 on the Australian tropical cyclone scale.
The low-pressure area formed into a tropical cyclone two days later and quickly strengthened into a Category 5 storm on the Australian tropical cyclone scale.
Between 1 and 2 April, the storm quickly intensified and attained its peak intensity as a Category 5 cyclone on the Australian cyclone intensity scale.
It ultimately peaked at Category 3 intensity on the Australian tropical cyclone scale.