Original: After forming over the Arafura Sea, the storm moved upward and affected the city with Category 4 winds on the Australian cyclone intensity scale, while there is evidence to suggest that it had reached Category 3 on the Saffir-Simpson Hurricane Scale when it made landfall.
Simplified: After forming over the Arafura Sea, the Tracy moved south and hit the city with Category 4 winds on the Australian cyclone scale. It is possible that it had reached Category 3 on the Saffir-Simpson Hurricane Scale when it made landfall.