What to look for:

We will be recording the first official snowfall as one that is 1/10 inch deep covering most of the ground.

Did you know that there is a difference between snowflakes and snow crystals? Snow crystals are the individual shapes that are formed high in the atmosphere. Sometimes they fall all the way to the earth’s surface as crystals. When you cut "paper snowflakes", you are probably really cutting "paper snow crystals!" If snow crystals clump together, they make a snowflake.

To make a snow crystal, three things need to be present in the air at the same time:

• cold temperature
• water vapor
• a freezing nucleus (like a piece of dust.)

If conditions are just right, water molecules will freeze on the dust, one at a time. Because they join together in a regular pattern, they form a starter "hexagonal plate" crystal. The final crystal shape depends on the temperature and other weather conditions. Check out the different shapes that you might find falling from the sky:

How can snow keep things warm?

When people use the phrase "blanket of snow" they aren't kidding! Snow is a great insulator, it works just like the quilt on your bed to trap heat released from the earth. This can create a pocket of warm air right next to the ground. In fact, if you were to stick a thermometer into the bottom of a snow bank, you might find temperature at the bottom to be in the thirties, even if the air temperature around you is below zero degrees. This becomes very important for the winter survival of many plants and animals. Small mammals like mice do not have much fur or fat to keep them warm and so they spend most of their time in the warmth under the snow. A cold winter that does not have much snow can be very hard on small mammal populations.

Cool Facts