High quality simulated twister made from maya particle containers. Has a separate layer for the dust cloud and the funnel cloud, which can be switched on and off according to layers.
An initial state is not set but starts to build the twister from frame 1.
Frame 50 the twister fills the rig for the then continued animation. The animation is set at 400 frames, but can be extended infinitely.

Setup includes correct lighting for tornado effect.

Additional Notes:
The twister was built for production quality use in maya and renderman as seen in the preview for detail. Shots in mental ray are also included. Preview render time: about 4min in renderman on dual core 2.5mhz, for full HD about 3.75hrs per frame.