Learning to appreciate the snow

By Katie Shipka

OSU Ext. master gardener volunteer

Even though our cold weather comes for only a couple of months during the year (I hear some of you cheering), we should appreciate it and the snow that accompanies it. How a snowflake is created is both interesting and educational.

The upper atmosphere is where a snowflake begins when a tiny particle of pollen or dust meets a cold water droplet that freezes into an ice crystal. Because it becomes heavier than the surrounding atmosphere, the water vapor freezes and clings to the crystal, gaining in size and diameter. Ice crystals are symmetrical and form hexagonal or six-sided patterns, because water molecules follow a pre-determined pattern as they arrange themselves.

The formation of these crystals is caused by many factors, but primarily temperature, water vapor and humidity.

A crystal, while falling earthward because it is heavier than the atmosphere, comes in contact with varying conditions which determine how the points form and grow.

As the crystal drops through the atmosphere, it collects more water vapor, freezes and continues to expand in both size and shape. Long, needle-shaped crystals occur often in temperatures of about 23 degrees, and flat crystals occur more often at 5 degrees.

Humidity and temperature can adjust the crystal growth in varying directions, branching off in pointed, needle or lacy patterns. In addition, the more water vapor the snowflake absorbs, the heavier the flake becomes.

Snowflakes will reach the ground as snow only if our temperature is below the freezing point of 32 degrees. If snowflakes pass through the atmosphere and come in contact with temperatures above the freezing point, they melt, refreeze and land as sleet. In freezing rain, snowflakes pass through a wider layer of warm air and are melted completely, landing on the cold earth, which produces icy conditions.

Determining weather conditions is challenging for a meteorologist. Knowledge of the amount of moisture in the air, studying which direction winds arrive or pass over an area, and studying elevations all play a role in determining our weather future. I am often amazed at how accurate the forecasts are, considering all the variables.

Soon the snow will melt with the approaching spring weather, and the winter plans for our summer gardens will have already been made.

When we understand how snow forms and why, we can learn to appreciate it while it is here. To learn more about the science of snow, visit http://go.osu.edu/snowscience.

Beyond the awesome science of how snow is made, gardeners and farmers alike should appreciate snow and its effect on soil fertility. Michigan State tells us that snow and rain together provided 2 to 22 pounds of nitrogen per acre, per year. To learn more about the positive impacts of snow, vitis http://go.osu.edu/snow-N.