In Alaska, we get plenty of snow. But what do we really know about it?

Snow. There has been plenty so far this season. Anchorage is looking at its snowiest December ever. Statewide, there is snow everywhere. The Interior has seen plenty of snow at all locations, but the snow that falls inland tends to be dry and not quite as disruptive or as hard to move as coastal snow.

While Alaskan folks understand quite well how to move snow, how much do we really know about snow?

Snow is formed when there is high moisture content in the clouds and the temperature falls to around 32 degrees. Water droplets freeze together until they get heavy enough to fall. As they fall the frozen droplets cool the air around them, leading to more snow and the potential for snow forming at warmer temperatures. At some point, the warming air lower down in the atmosphere may turn the snow into sleet or rain. In the right conditions, snow can form at 40 degrees or warmer.

The tiny droplets that become snowflakes form ice crystals that begin to grow as water molecules in the air are deposited onto the crystal as it falls through the air and clump together to form a snowflake. All snowflakes are hexagonal. This structure allows water molecules — composed of one oxygen and two hydrogen atoms — to form together most efficiently. While it is said that no two snowflakes are the same, this is impossible to test. However, as a general rule, it is likely true, given the limitless possibilities of temperature and humidity.

This past August, snow was accumulating on the highway near Midway, halfway between Fairbanks and Delta Junction, at nearly 70 degrees. The highway had a couple inches of slushy snow for a two-mile stretch. That definitely slowed the tourists down. This event was possible because of a super-cooled thunderstorm that was able to dump very heavy snow fast enough to reach the ground without melting.

Snowflakes are generally lumped into three basic types. Dendrites, which are the most common type in Alaska, are the delicate tree-like shapes, formed in very low temperatures. These are the slow falling flakes that we like to catch on our tongues. Thin plate snowflakes are just that — plates. These are formed when there is not quite enough moisture to make the branches that we see on dendrites. Sector plate flakes are the middle ground between the dendrites and thin plate snowflakes. Branches start to form but they can’t quite complete the branch because of the lack of moisture.

[A sourdough’s guide to moving snow]

Snowflakes appear white to our eyes as they fall and accumulate. They are actually clear, though not as transparent as glass. They are translucent; light passes through them indirectly. The many sides of the ice crystals diffuse the reflection of the light spectrum, which results in the snowflake appearing to be white.

Most snow falls at 1.5 mph, taking about an hour to touch down. The heavy stuff, more like sleet, can ramp that speed up to 4 mph. Ice pellets are a bit different. They form from thawing snowflakes that refreeze as they fall through super-cooled air. The flakes stick together in irregular shapes; spherical but not necessarily round, they bounce when they hit the ground, not being quite as solid as true hail.

Associated with snow, but not snow, is freezing rain. This phenomenon begins as snow, melts as it falls and passes through a layer of super-cooled air, which cools the water. The water drops are falling fast enough to cool but not quite freeze. They can hit the ground well below freezing and freeze instantly on impact, encasing the ground or snowpack in a layer of ice. A year ago, Delta Junction and surrounding areas had freezing rain for several hours. The snow depth at that time was approximately two feet. The inch of ice that formed was solid enough to walk on. Tough on roofs, hard on critters and hard to move.

As Alaskans, we have long enough winters to learn all about moving snow out of our way. We also have learned many ways to enjoy and use the white stuff that accumulates around us for eight months of the year. Snowmobiling, running dogs, skiing and snowshoeing — oh, I love snow! Shoveling snow from the porch for the sixth day in a row — not so much.