I have been looking at ways for interpolating in between precipitation radar (and forecast) frames to create a smooth video from it. I've found that morph_files mostly works for this. It does go completely bonkers under some circumstances* and could definitely do with some tweaks (for instance blending at the boundary between the radar and forecast rather than morphing). I thought I'd share some of my results here anyways.
Here is a video:
And here there is a live version:
(*) for instance if there is only a small patch of rain left and it disappears the result is what I'd call a supernova. Huge values before the darkness.