What is typically a characteristic of stable air masses?

Stable air masses are typically characterized by their resistance to vertical movement. This stability occurs when the temperature increases with altitude, which means that the air near the surface is warmer and less dense than the air above it. As a result, the air mass does not easily rise, leading to minimal mixing and promoting clear skies. In stable air conditions, any upward movement that does occur is often limited and has difficulty forming clouds.

The other options present characteristics that do not align with stable air. For instance, the first choice refers to conditions conducive to cloud formation, which is more typical of unstable air that allows for rising air and convection. The third option suggests rapid temperature fluctuations, which is more common in unstable atmospheres where convection or mixing occurs. The last option implies increased instability and rising air currents, which describe conditions leading to turbulence and cloud development rather than the calm, clear characteristics of stable air.