Surfing - During summer, heavy swells are generated when cyclones form in the tropics. Tropical cyclones form over warm seas, so their occurrence is influenced by El Niño & La Niña cycles. Their movements are unpredictable. They can even move westward, which is unique for a large scale weather system. In 1979, Tropical Cyclone Kerry wandered for 3 weeks across the Coral Sea and into Queensland, before dissipating.