Which combination of weather-producing variables is likely to result in cumuliform clouds and showery rain?

The combination of unstable, moist air and orographic lifting is critical for the development of cumuliform clouds and showery rain. Unstable air is characterized by a tendency to rise, creating conditions that favor the growth of vertically developed clouds, such as cumuliform clouds. These clouds develop as moist air is lifted, cooled, and condenses into water droplets or ice crystals, leading to the formation of clouds that can produce precipitation.

Orographic lifting occurs when air is forced to rise over a mountain range or elevated terrain. As the moist air ascends, it cools, and if the instability is sufficient, it can lead to the rapid development of cumulus clouds that grow and produce showers. The moist air provides the necessary moisture for cloud formation and precipitation, while the lifting mechanism ensures that the air reaches higher altitudes where cooling occurs.

This combination of unstable conditions and vertical lifting stimulates the development of convective activity, which is often associated with showery precipitation. Other scenarios, such as stable atmospheres or dry air, do not support the same level of cloud development or precipitation, as they lack the necessary rising motion and moisture content.