Final answer:
Snow is created when there is cold air temperature, high relative humidity, and commonly low air pressure.
Step-by-step explanation:
The combination of factors that creates snow involves a cold air temperature, high relative humidity, and often low air pressure. When the air temperature drops, its capacity to hold water vapor decreases, and high relative humidity means there is a lot of moisture available in the air. Low pressure areas often accompany weather systems that can cause the air to rise and cool, which helps condensation and snow formation. For instance, if the temperature drops from 25.0°C to 15.0°C, with an initial relative humidity of 90%, a significant amount of water may condense out of the air. This condensation can create heavy dew or fog, and under freezing conditions, it can lead to snowfall.