Then they had fun using this chart of snow crystal types to identify photos of magnified snow crystals.
We also had a discussion about the uniqueness of snowflakes and why they are all different, the likelihood of finding two that are exactly the same, and why snow crystals don't hold their structure for very long once they have fallen to the earth -- you pretty much need to capture them and look at them right away in order to see their structure.
Then they headed outside with magnifying glasses. There had been snow flurries a little earlier, and the host mom had put out black felt to catch some of the snowflakes on so that the kids could look at them through the magnifying glasses and the microscope. Unfortunately, it was actually above freezing outside that day (who woulda thunk it!) so the structure wasn't as intact as it could have been. That's OK, I think we can manage to catch some fresh snowflakes here at home at some point soon (unfortunately....).
Then the kids sat down with their snow crystal charts and craft supplies and worked on putting together some of their own snow crystals.
In my kids' case, we tied this in with the Enki Nature Story, "Crystal" at home, which is about snow formation and the water cycle.