While most of the world sees snow as an inconvenience your lawn loves it.  It does several things to keep your lawn happy an alive.  

• Protects it from the wind.  In the winter the cold dry wind can dry out the ground just as fast, or faster than a windy, 100 degree day.  The snow provides a blanket that shields the soil, roots, and grass from the wind drying it out.   

• Moisture.  Snow has plenty of moisture and while the grass is dormant it is not dead.  The grass still needs some moisture to survive.  A typical Lincoln, NE winter is, we see snow then cold, then melt, then snow and repeat for the entire winter.  When snow melts it melts very slow compared to a heavy rain.  This means all the moisture from the snow make it into the ground to provide benefits to your lawn rather than running off into the creeks and streams. 

• Helps keep hard frost out of the ground.  When we have a season long snow coverage, we will see not as deep of a freeze.  A deep, hard, cold freeze can be bad for your lawn because it dries out the ground.  Similar to freeze dried candies or freezer burnt food. 

Overall snow provides protection and moisture for your lawn to keep it alive and shielded from the harsh winter weather.  All of these things contribute to preventing winter kill, the biggest problem your lawn will face in the winter.