Powder, packed or slush, it’s all snow

Now that we’ve gotten a little bit of snow under our belts, a little more than 19 inches so far this season, I thought it would be fun to dedicate an entire column to the “white stuff.”

It’s often been said that Eskimos have more than 100 words for snow. Though we may not live in a climate of year-round winter, there is no shortage of terminology to describe the winter precipitation we see here locally. Just ask any skier. Skiers may talk about powder, packed powder, or slush, while meteorologists differentiate between snow grains, snow pellets (also called graupel or soft hail), and snow flakes. Technically speaking, a snow flake is a conglomeration of individual snow crystals that stick together as they fall to the ground.

To skiers, shovelers and snowball makers, the liquid content of the snow is very important. Colder temperatures in the teens and 20s mean the air can hold less water vapor, which results in snow that has a lower liquid content and is powdery. That is great unless you want to build a snowman. Warmer temperatures in the 30s result in snow that has a much higher liquid content. It makes for great snowballs, and backaches as well for those with shoveling duty.

At weather-observing stations, the instruments are not able to measure snowfall directly. The snow is melted to what’s called its liquid equivalent. Without an actual visual report of snowfall from a human observer, meteorologist sometimes have use a water/snow ratio to estimate snowfall. This ratio is also used when forecasting snowfall amounts because the computer models only provide a forecast for liquid equivalent A general rule of thumb in this area is the 12-to-1 rule. In other words, 1 inch of water would produce 12 inches of snow. The ratios, however can vary from 5-to-1 for heavy, wet snow, all the way to 100-to-1 for a very dry, powdery snow.

As many folks dream of a white Christmas, you may have wondered what makes snow white in the first place. As a beam of white sunlight hits a patch of snow, the light is scattered by the millions of ice crystals and air pockets. Since the snow absorbs very little of the light that hits it, the light essentially bounces back or is reflected back at our eyes giving the snow a white appearance.

Is it true that no two snowflakes are alike? Theoretically speaking, it is possible that there would be duplicates based on the unimaginable number of snowflakes that have fallen since the beginning of time. The probability, however, of a person ever finding two identical snowflakes is nearly zero based on their complex crystalline structure. A Vermont man named Wilson “Snowflake” Bently took the first photograph of an individual snow crystal in 1885. Over his lifetime he photographed more than 5,000 snowflakes, not finding any two alike.

So far this month, we’ve seen more fog than snow in Coeur d’Alene, as high pressure has kept things pretty quiet. Some pretty big early December snowstorms have hit the area in the past, however. In 1927, a Dec. 12 blizzard dropped 13 inches of snow in Coeur d’Alene, which was a 24-hour record. In 1971, the week of Dec. 13 brought 10 to 16 inches of snow across North Idaho. And on Dec. 6 in 1977, Coeur d’Alene received a whopping 11 inches, while 16 inches buried Hayden Lake.

The snowiest December ever occurred in 1915, when Coeur d’Alene saw a total of 63.6 inches.