Unnamed system

History

Tropical Cyclone Unnamed 09U was a short-lived, weak system that formed on 8 January 2025 as a tropical low south of Christmas Island, developing out of an elongated atmospheric trough extending through Indonesia. The Madden–Julian Oscillation was in a suppressed phase at the time, providing no broad climate support for development. The system initially tracked westward before turning southward on 9 January and moving over the open waters of the Indian Ocean.

Post-season reanalysis by the Bureau of Meteorology determined that the system briefly reached Category 1 intensity on the Australian scale, though it was never named during its operational lifetime, having been tracked throughout as a tropical low. At its peak on 10 January 2025, gale-force winds extended into all quadrants for a period of six to twelve hours, with maximum sustained ten-minute winds of 75 km/h and a minimum central pressure of approximately 1000 hPa. By midday on 10 January the gale-force winds had retreated to the southern quadrants only, and by 11 January the system had weakened below cyclone strength. It dissipated entirely over open water by 13 January 2025.

The system remained well away from land throughout its lifespan and had no impact on Christmas Island, the Cocos (Keeling) Islands, or the Western Australian coast. No casualties or damage were recorded.

Sources: Bureau of Meteorology report