With the next update the Birch Forest Biome will also support procedural autumn and winter. Here is a little preview.
Some close up shots of the snow and more videos you can see here: https://www.artstation.com/artwork/PoBR1Z
https://www.youtube.com/watch?v=tDvBmSTK3IE
MAWI Store Page:
https://www.fab.com/sellers/MAWI%20United
UE4 Procedural Winter Storm