It snows in three places- on Main Street, by IASW, and by the river. It is marked on the map where it will happen, with giant snowflakes.
I lasted about 5 minutes each time, and you can tell when it is about to start because you can hear whatever they use turn on.
It happened during the castle lighting/IASW projections, and again at the end of the fireworks.
It's very cool, and not to be missed! Especially the one after the fireworks on Main Street. We saw it in all three places and thought that one was the best place and time.