Snowflakes - Explained

What controls the type of powder that we ski? The size and shape of snowflakes are determined by the temperature and moisture content of the air.

Large dendrite snowflakes create the lightest, fluffiest powder for skiers and riders. Colder temperatures and a higher amount of moisture in the air are the conditions necessary for fluffy powder.

How do snowflakes form?

All weather requires both moisture and lift. The combination of these two ingredients creates precipitation. Snow is created by converting the moisture into snowflakes.

Rising air expands as pressure decreases as you move up in elevation. Expanding air cools, and this cooling helps to condense the water vapor into liquid water drops. Most fluffy-looking clouds are made of tiny liquid water drops while high, thin clouds are made of tiny ice crystals.

Snow is not frozen rain. Water vapor is attracted to and clings to very small condensation nuclei like dust or airborne salt or even other snow crystals. Often the crystals combine with other crystals and grow into snowflakes.

Types of Snowflakes

This background explains how snowflakes form, but it doesn’t explain why there are different types of snowflakes and how they create different types of powder. For that, we need to get more specific.

Based on the snowflake diagram, different combinations of temperature and moisture produce different types of snowflakes. Heavier/thicker snow is often produced by dendrites formed in warmer temperatures between about 26 and 32 Degrees Fahrenheit with a good amount of moisture in the air (moisture is shown by the y-axis or left axis). When temperatures are very cold, the smaller amount of moisture in the air tends to produce small plates or columns (right side of the image).

In between this range is the beautiful, large, stellar dendrite produced with the combination of plentiful moisture and temperatures between about 0 and 10 Degrees Fahrenheit. This is the big snowflake at the top of the graph. Because these snowflakes are "perfectly" shaped with six points, they tend to stack on top of each other instead of packing tightly together. Stacked snowflakes ensure that the new snow is mostly made up of air pockets, and this is what creates the perfect snow conditions with light, "blower" powder.

Read More: Perfect Powder - Explained

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