Here we go. A very hard thing that I start here. You can see it in the topic subject, I want to create a tornado. I want it to be realistic, fast(no low fps), and moveable.

It could do random movements (with a limit of distance), and would die after some seconds / minutes .

Here's a video of a realistic one, pretty amazing (thanks to people who gave me the link)

Video on YouTube

Anyway. It would be nice if anyone could give his idea on how to make a good looking tornado.

But For what? For my storm chasing game, Fujita5. You can check out this post:
Here

Thanks in advance.
Mark