Custom Flowmaps?
OK, what I told you was to check out that summary of the main properties the SolidEnergy shader has that I made here. There you're linked to the little program that can help you make your own custom flowmaps.
For example, for the Winter Testing Initiative fizzler, I thought it would be nice if the flowmap movement was painted downwards so that you can see the snowflakes like falling.
Just do some testing with that program and make the movement as you wish. Once you have a .PNG file image after saving it (pressing the button "Bake to Texture"), use whatever image-editor capable to later save it as VTF, and to add an alpha layer and play with different intensity/transparency of it in order to achieve a good result for the movement 
Don't hesitate to ask if you find difficulties with said program.