The two elements that impact snowfall depth
The primary factors that determine how much snow will fall in a storm system are the air temperature and moisture content of the atmosphere. That means there's a sliding scale for predicting the amount of snowfall, starting with the likelihood of crystalline structures forming in particularly cold air. Those crystals bolster the size and width of the snowflakes and allow the snow to pile up quickly and at greater perceived depths as there is more air between the "fluffy" crystalline flakes. Even in an atmosphere that is nearly moisture-starved in the winter, the snowfall depth would be enhanced by these crystals. The ratio of snow to melted snow-moisture content can go up to 30:1 in a sub-zero temperature environment!
Conversely, in a warmer environment the ratio can be much smaller, especially where more moisture is available. With temperatures in the lower 30s, that ration is typically around 10:1, or ten inches of snow for one inch of precipitation (melted snow) and even 8:1 with temperatures in the mid 30s.