A surface depression formed on 20 January 1980 about 1000 km west-northwest of Cocos Island in an elongated monsoonal trough which extended from near the east coast of Africa to northern Australia. The system moved slowly southeast and late on 21 January 1980 was estimated to have reached tropical cyclone intensity. At 1200 UTC on 22 January 1980 a ship about 200 km to the northwest of Clara reported a mean wind of 55 km/h. However, at about this same time Clara was entering the periphery of the circulation around the severe tropical cyclone Brian and the system rapidly weakened to a tropical depression as the low-level circulation was moved eastward at about 30 km/h and became completely separated from the high-level outflow. This type of sheared flow pattern was evident in satellite photographs throughout Clara 's lifetime.
Satellite imagery indicated that Clara regained tropical cyclone strength on 24 January 1980 but was only ever a weak to moderate storm. Peak intensity occurred at about 1200 UTC on 26 January 1980 with a minimum central pressure of about 980 hPa and a maximum sustained wind of about 100 km/h. At 0000 UTC on 27 January 1980 a drill ship about 200 km southeast of the centre reported a sustained wind of about 75 km/h. On 27 January 1980 strong northwest winds in high levels of the troposphere sheared away the outflow region of the cyclone and as a weakening depression Clara was carried westward until it dissipated late on 29 January 1980.
The most interesting meteorological features of Clara were its interaction with the intense tropical cyclone Brian and the shear type cloud patterns displayed by the storm over most of its life cycle. This frequently made location of the centre by satellite imagery difficult.