- A storm is a source of precipitation
- Snow is a kind of precipitation
- Rain is a kind of precipitation
- Hence, a storm is a source of rain / snow

- A storm is a source of rain / snow
- A thunderstorm is a kind of storm
- Hence, a thunderstorm is a source of rain / snow

- A thunderstorm is a source of rain / snow
- Cold fronts cause thunderstorms as they pass by
- Hence, cold fronts will cause rain / snow as they pass by

Hence, cold fronts will cause rain / snow as they pass by
Question
What most likely happens when a cold air mass comes into contact with a warm, moist air mass?

Context
- A storm is a source of precipitation 
- A thunderstorm is a kind of storm 
- Snow is a kind of precipitation 
- Rain is a kind of precipitation 
- Cold fronts cause thunderstorms as they pass by