Create Falling Snow

Hello there

I was follwoing the tutorial for the falling snow and it works perfectly, really good , but i was wondering if some would know how to stop the falling snow effect in the time line.

I only need the falling snow for a few parts of the movie (let say from frame 1 to 10), then when you click in a button and it takes you to a few frames ahead,(frame 15)

i do not want the snow to keep on falling after frame 15 i would like it to stop and only start again if you click back to that part of the movie where it is suppose to be snowing.(frames 1 to 10)

Anyone can help?

Cheers