What is snowmaking?
Why is snow a good insulator?
Does snow change how sound waves travel?
Why is snow white?
What is the difference between "Dry Bulb Temperature and "Wet Bulb Temperature"?

What is snowmaking?
Snowmaking machines make snow by breaking water into small particles, cooling the water by causing the water particles to move through cold air, nucleating the water particles and distributing the resulting snow on a surface.

Why don't people just sprinkle water to make snow? Water is a unique material, it expands when it freezes and it has high heat of fusion, thus your ice cubes float and last a long time. Heat of fusion means that one can cool a pound of water say from 65°F (18.3°C) to 64°F (17.8°C) or 34°F (1.1°C) to 33°F (.6°C) by removing 1 BTU. But to convert one pound of liquid water at 32°F (0°C) from a liquid to one pound of ice at 32°F (0°C) requires the removal of 144 BTUs. Thus, a large amount of heat removal (cooling) is required. Also, water can be cooled well below 32°F (0°C) and still stay a liquid unless it is nucleated.

So a snowmaking machine a) breaks the water into small particles, b) cools the water to 32°F (0°C), c) removes the heat of fusion, and d) nucleates.

Why is snow a good insulator?
Fresh, undisturbed snow is composed of a high percentage of air trapped among the lattice structure of the accumulated snow crystals. Since the air can barely move, heat transfer is greatly reduced. Fresh, uncompacted snow typically is 90-95 percent trapped air.

Does snow change how sound waves travel? 
I recall waking up as a child and without even looking outside knowing that it had snowed just from the sounds I could hear. Yes, when the ground has a thick layer of fresh, fluffy snow, sound waves are readily absorbed at the surface of the snow. However, the snow surface can become smooth and hard as it ages or if there have been strong winds. Then the snow surface will actually help reflect sound waves. Sounds may seem clearer and travel farther under these circumstances.

Why is snow white?
Visible sunlight is white. Most natural materials absorb some sunlight which gives them their color. Snow, however, reflects most of the sunlight. The complex structure of snow crystals results in countless tiny surfaces from which visible light is efficiently reflected. What little sunlight is absorbed by snow is absorbed uniformly over the wavelengths of visible light thus giving snow its white appearance.

What is the difference between "Dry Bulb Temperature and "Wet Bulb Temperature"?
What you see on a thermometer is called dry bulb temperature or ambient air temperature. In terms of physics, there's no such thing as "cold." There is only heat, more heat, and less heat. The lower the humidity, the more snow a snow machine can make at a given temperature.

This is how the humidity works: On a 90° day with 40 % relative humidity, you feel much cooler than you do on an 85° day with 95 % relative humidity. The reason for this is because your body gives off heat more easily through radiational cooling when the air isn't saturated with moisture.

A droplet of water from a snow machine gives off heat more readily when the humidity is low than it does when the humidity is high.

Combination of dry bulb temperature and relative humidity is called the wet bulb temperature. When the air is saturated (100 percent relative humidity), the dry bulb and wet bulb temperatures are identical. But when the air is drier than 100 percent, the wet bulb temperature will be lower than the dry bulb.

Click here to see a chart illustrating this principal (also can be used as a your guide for snowmaking).