SALLY

History

Tropical Cyclone Sally was a short-lived and remote system that developed over the eastern Indian Ocean in January 2005, well away from the Australian mainland. Its origins lay in an area of convection that began organising on 6 January roughly 930 km west-southwest of Jakarta. Conditions were sufficiently favourable for the disturbance to consolidate, and by the following day, 7 January, it had acquired a closed circulation and was classified as a tropical low.

The low drifted generally southwards while gradually strengthening, and on 8 January it was upgraded and named Sally at a position about 370 km east-southeast of the Cocos (Keeling) Islands, within the area of responsibility monitored from Perth. A mid-level ridge positioned to the system's southeast provided the dominant steering influence, nudging Sally onto a slow south-westward course that carried it past the Cocos Islands group at a distance.

Sally continued to deepen modestly during this phase and attained its peak intensity on 9 January, with maximum sustained winds estimated at 95 km/h. The strengthening trend was abruptly halted soon afterwards. An intrusion of dry air into the circulation, combined with a marked increase in vertical wind shear, stripped the convection away from the centre and caused the cyclone to decay rapidly. Sally fell below tropical cyclone strength and dissipated early on 10 January, at that point located approximately 460 km west-southwest of the Cocos Islands.

Because the cyclone spent its entire existence over open water and tracked away from inhabited areas, Sally produced no recorded impacts on land. No coastal communities were threatened, no damage or casualties were attributed to the system, and it required no evacuations or emergency response. Its significance is therefore largely meteorological, as an example of a cyclone whose development was cut short by a hostile mid-level environment. Sally was one of several weak, ocean-bound systems recorded during the slightly below average 2004–05 Australian region cyclone season.

Sources: Bureau of Meteorology report Wikipedia