Closest thing I could find was
this but it doesn't apply to our phones.
To be honest, I don't think this is possible (or feasible). The weather animations are in a single file. Their non-manila state is a singe .brn file. The animations fade in and out, so they would look very strange anyways. A very dirty way to do it would be editing the animation files and duplicating the frames to increase the number of times the animations play, but this would make the file VERY large, and it would only play for however many times you duplicated the animations.
The BEST way I can think of to make this would be finding the command initiated when you move the the home tab. You could make a shortcut to this command, but you would then need to figure out how to have the shortcut constantly replay.