While everyone is playing with these shapes, don't forget it started with hurricanes...
This is a great thread, that needs to continue! I love tornados!
That last post of the funnel shape (whith the 'less than' - 'greater than' issue) made me think of a waterfall... The shape, less filled with clouds, so foamy bits remain, and a reflective surface behind it, could very much resemble a waterfall don't you think?
BTW, I don't get these functions, because I don't know which does what. Is there a simple guide for them, or can one of you guys make one?