Thanx for the link to the snow machine, although the OP started this thread 5 years ago. Here is the link to Ockham's current version of the Weather Kit...

 http://ockhamsbungalow.com/PPP/Weather2.zip

Misty,

Large snowflakes can cast a shadow when they are close to a surface, but if there is any accumulation the indirect light overwhelms it.  Also, it is usually cloudy when it snows, so there is diffuse illumination, which leads to very diffuse shadows.

----------------------------------------------------------------------------------------

The Wisdom of bagginsbill:

"Oh - the manual says that? I have never read the manual - this must be why."
“I could buy better software, but then I'd have to be an artist and what's the point of that?"
"The [R'osity Forum Search] 'Default' label should actually say 'Don't Find What I'm Looking For'".
bagginsbill's Free Stuff... https://web.archive.org/web/20201010171535/https://sites.google.com/site/bagginsbill/Home