Every time I looked at the animated weather app, I would see the animation start in the past where clouds moved and grew and shrank naturally. As soon as it passed the present moment, the clouds would become fixed shapes and continue on whatever their current vector is. In the visualization there was no attempt to model clouds growing and shrinking. The clouds would suddenly start skidding across the screen.

I've read that is what the underlying precipitation "models" did as well, but obviously can't confirm.