The active cloud cluster from which Viola developed formed about 600 km to the northwest of Cocos Island on 7 December 1979. It was part of a semi-continuous line of convection extending eastward across Indonesia. A tropical depression had developed by 9 December 1979 and moved slowly to the southwest. Using the Dvorak intensity analysis technique Viola reached tropical cyclone intensity at about 0300 UTC 11 December 1979. The cyclone then began to move westward under the influence of an easterly middle level flow north of the sub-tropical ridge.
Viola attained its maximum intensity late on 16 December 1979 when the central pressure was estimated to be near 930 hPa giving a maximum mean wind speed of about 205 km/h. It maintained this intensity as it crossed into the Mauritius Region early on 18 December 1979.
Viola was renamed Claudette and passed close to Mauritius late on 22 December 1979 causing the loss of six lives and injuring 21 people. It was reported that the sugar cane crop on Mauritius was devastated and that buildings suffered considerable damage.
Severe tropical cyclone Viola was notable for its small size and long lifetime. Satellite pictures showed that nearly all of the intense convective activity was within 200 km of the centre. Including the pre-cyclone and post-cyclone stages the storm lasted about 18 days from 9 December 1979.