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 devasta