The Hometown Treasure January 2011 | Page 29

January 2011 on Winter Snow cold air makes very light, dry snow. The warmer the air, the wetter the snow will be. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by external pressure. Snowflakes which fall in the form of a ball, due to melting and refreezing, rather than a flake, are known as graupel. These are also sometimes called snow pellets, ice pellets, ice granules , snow grains or sleet. Snowfall amount and its related liquid equivalent precipitation amount are determined using a variety of different rain gauges. The process of precipitating snow is called snowfall. Snowfall tends to form within regions of upward motion of air around a type of low-pressure system known as an extratropical cyclone. Snow can fall poleward of these systems’ associated warm fronts and within their comma head precipitation patterns. They are called this due to the comma-like shape of the cloud and precipitation pattern. continued on next page Phone: 260-463-4901 • Fax 888-439-6528 • The Hometown Treasure A fresh start to a new year reminds me of a fresh blanket of snow and the Christmas season. Snow is a beautiful sight to see, especially when it falls from the sky as big flakes. A pure white snow-covered ground resembles purity and a clean atmosphere, doesn’t it? Let’s take a joyful ride in this journey we call snow to get a better understanding of frozen rain … which is what snow is, for the most part. Why is there snow? Snow is frozen rain. Droplets of water in a cloud form tiny ice crystals that turn into snowflakes. Snow is made of water and air. Snow is mostly air, so a very small amount of water will make a large amount of snow. Where do snowflakes come from? Snowflakes are formed from tiny crystals of frozen water droplets. As the flakes grow, they take on different shapes. Different kinds of flakes make different kinds of snow. Kinds of flakes depend on the temperature. Very January 2011 Spotlight Nature by David Lane, Indiana Master Naturalist Page 2 ?((