Need help with snow falling (not the simple case)

Hi,

searched the web and forums, for this, couldn’t find answer.

The idea is to make falling snow and the snowflakes should stay on a logo (those that reach top of the logo). The question is how to make snowflakes stay on the logo.

I have an idea how to make the snowflakes stay if the top part of the logo is a straight line. But how to do it in case the top of the logo is not a straight line but shape with different bends and curves and shapes?

I’d also like the snow to form heaps eventually so that the next snowflakes fall on top of the previous ones.

Maybe someone has any idea or can point to a tutorial?

Thanks in advance for your help.