https://i.ytimg.com/vi/0hF09YMnuKg/hqdefault.jpg 720p recommended Tests done with Blender’s smoke simulator, internal render and compositing. Update 2 : Tutorial available on Blendercookie.com http://cgcookie.com/blender/2012/05/02/creating-a-tornado-in-blender-with-particles-and-the-smoke-simulator/ Update : I’ve added an artwork here : http://tomwalks.deviantart.com/art/Tornado-3D-Blender-2-62-297222073 The smoke resolution is set to 64 (division), with high resolution set to 3. A little more than an hour to bake, 4 to 5…