Wow this is really cool twister! I love twisters, in fact Twister (1996) is a favorite film of mine.
I'm curious what this would look like utilizing Voronoi Ridges for noise or Perlin Ridges. I notice as it twists, along the boundary you can see "circular" plumes spin, which I'm not sure is too conducive with a twister, at least with the main column (not the outer effect).
Otherwise though this is really amazing work. :O