There are two ways, used together, to deal with this. 1. "Activate" the particle emitter ahead of where the animation begins. In addition to duration of the emitter, you can designate when it starts and completes within the animation 2. Do not allow a particle quantity range (the +/- feature). Instead, have a specific number of particles for any given time. The problem that you may still have is the location of the particles when it comes time to loop the animation. Since snow is erratic, while you may control the quantity issue, the particles will not be in the same place when the animation loops. This may be cotrolable by the parameters for the motion. However, I don't have time to play with it today and see! :( Mark