What term describes the atmospheric conditions when clouds form in layers?

The term that describes atmospheric conditions when clouds form in layers is "stable." In stable air, the atmosphere is structured in such a way that vertical movement of air is limited. This stability allows for the formation of stratiform clouds, which are layered and often indicate a lack of significant vertical development.

In stable conditions, warm air may be trapped near the surface, with cooler air above it, preventing upward movement and leading to cloud formation over wider horizontal areas rather than vertical. Such conditions can result in overcast skies and are often associated with stable weather patterns.

Conversely, unstable conditions are characterized by buoyant air that rises rapidly, leading to the development of cumuliform clouds, which are typically puffy and can indicate potential for thunderstorms. Turbulent atmospheric conditions involve chaotic and unpredictable movements of air, making it conducive to varied and dynamic cloud formations. Variable conditions would indicate fluctuations in the atmospheric state, but do not specifically apply to the layering of clouds. Therefore, the term "stable" precisely describes the situation where clouds form in layers.