Hi @Leen
There are free videos of snow available with transparent backgrounds like this.
Sparkle doesn’t support transparent background directly, but if you don’t mind the underlying image being a little darker from a black video background, you can make the video semi-transparent and get a good effect without much effort.
If the darkness is too annoying, you could try Duncan’s workaround for transparent video.
I haven’t tried it myself, but I think a Lottie animation might be another option. I didn’t see any realistic snowfall ones in a quick search, but you could potentially make one with something like Keyshape.