When snowballs start to spawn (December 12th) You build a Snowmam and give her 5 snowflakes and she'll give you a piece from the Ice Series which is unorderable
Yesterday it showed for a short period of time. Caught some snowflakes and sold them at retail.
Tip use your extra player that doesn't play a lot. Let them catch the snowflakes and keep them in their pockets.
It should speed things up when you make your first Snowmama. Don't go for the 5 snowflake one. Wait till you make a better snowmama and she only asks for 3 flakes. You should be able to collect the whole set in one night.
The snow started on the 3rd for me, it wasn't there yesterday though but today my little town is getting some flakes. It's quite lovely, I can't wait to see it actually go full winter in game!
It snowed a few days after Thanksgiving, and again today!
It's fun to see all of the villagers enjoying the snow. It also looks quite pretty as it falls.