What primarily determines the formation of either predominantly stratiform or predominantly cumuliform clouds?

The formation of predominantly stratiform or cumuliform clouds is primarily influenced by the stability of the air being lifted. When air is stable, it resists vertical movement, leading to the development of stratiform clouds, which are generally layered, uniform in appearance, and associated with stable weather patterns. These clouds form as moisture-laden air is gradually uplifted, spreading out horizontally and producing widespread cloud cover.

In contrast, when the air is unstable, it tends to rise more vigorously, allowing for the rapid vertical development characteristic of cumuliform clouds. These clouds are often puffy and tower into the atmosphere, typically associated with more turbulent weather conditions and are often linked to thunderstorms.

While other factors, such as the source of lift, humidity levels, and precipitation types, certainly play a role in cloud formation, it is the stability of the atmosphere that primarily dictates whether clouds will be stratiform or cumuliform.