A moist, unstable air mass is often characterized by which of the following?

A moist, unstable air mass is characterized by the presence of cumuliform clouds and showery precipitation. This type of air mass tends to undergo convective processes, leading to the formation of towering cumulus clouds that develop vertically as they rise, indicating instability. This vertical development often results in varying weather conditions, including thunderstorms and showers.

The presence of moisture in the air mass facilitates the condensation of water vapor as it rises, creating clouds that can produce precipitation in the form of showers. This is a typical behavior of unstable air masses, where the lifting of air leads to quick changes in weather, such as sudden downpours. The combination of destabilization due to heating or frontal boundaries enhances this process, reinforcing why cumuliform clouds and showery precipitation are hallmarks of a moist, unstable air mass.