Avalanche bulletins like the one from the Vancouver Island Avalanche Centre (www.islandavalanchebulletin.com) talk about snowpack and rain crust and fresh snow – snowflakes in large volumes.
This winter in particular, the Resort will be preparing for snow in large volumes, as weather prognosticators are predicting an La Nina year – which in turn means a lot of snow for Mount Washington.
But what about the single snowflake – the one that starts it all? Do you know where it comes from?
The first time anyone realized that snow was made up of individual crystals was in 1665, when Robert Hooke looked at snow under a microscope.
Since then, many scientists have studied snowflakes. In 1885, Wilson A. Bently (1865-1931) discovered that no two snowflakes are exactly the same. He took the first pictures of a snowflake.
Snowflakes and snow crystals are made of ice, but they are not frozen raindrops. Snow crystals or flakes form when water vapour condenses directly into ice. This happens in the clouds. Patterns in the crystals become evident as the crystals grow.
Many facts, from the ones above to those detailing the physics and characteristics of snow crystals, can be found on a website created by Kenneth Libbrecht, a physicist who studies snowflakes. You can read all about snow crystals and snowflakes at www.snowcrystals.com. If you’re really fascinated, he has a book section.
Libbrecht explains in his comprehensive website about the international classification system for snowflakes that categorizes the seven principal snow crystal types with many sub-types.
The most basic snow crystal geometry is a hexagonal prism. The more fancy ones are called “stellar dendrites” because their branches are tree-like, or “dendritic”. Ice crystals form in columns in colder temperatures.
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Did you know…that matching snow crystals were discovered in Wisconsin in 1988. They were hollow hexagonal prisms.
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Do you know…why snow is white?
Each individual snow crystal is clear. However, put a pile of them together and light reflects off all the many surfaces. Colours are reflected away or scattered equally, making the pile look white.