Which conditions are typical in an unstable air environment?

In an unstable air environment, the atmosphere is characterized by vertical motion due to warm air rising and cooler air sinking. This rising motion leads to the development of cumuliform clouds, which are often puffy and can grow vertically. The instability allows for the rapid ascent of warm, moist air, leading to the formation of showers and thunderstorms, which are associated with this type of cloud formation.

Showery precipitation is common in unstable conditions because the rising air can create localized areas of convection, leading to brief, intense rainfall. Cumuliform clouds typically indicate instability, as they are formed by the upward motion of air, which is a hallmark of unstable conditions. Thus, the presence of showery precipitation and cumuliform clouds is a clear indicator of instability in the atmosphere.

The other options describe conditions that are more typical of stable air environments, where stratiform clouds, flat bases, and calm conditions with minimal turbulence are prevalent. These conditions, in contrast to the dynamic and active weather associated with instability, lack the significant vertical movement needed to generate the characteristic showery precipitation and cumuliform cloud formations.