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coiled snow structure
I photographed this snow structure on the drive home from the Utah Science Teachers Association conference. It is about six inches across, and there were many more of different sizes. How did it form?

Answer:

This is a snow roller. They are fairly rare, and only form under special conditions. They need:

1. A layer of ice.
2. On top of that, a thin layer of very wet snow.
3. A slope.
4. Wind in just the right direction.

The combination of the wind and the slope cause the snow to roll up into a coil. I passed hundreds of snow covered road cuts on my drive home, but only one had snow rollers.

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