What flight condition often arises from unstable air?

The condition that often arises from unstable air is thunderstorms. Unstable air occurs when warm, moist air near the surface is lifted, resulting in significant vertical development of clouds. This rising air cools, and as it does so, it condenses and forms clouds, often leading to cumulonimbus formations that can produce severe weather, including thunderstorms.

This vertical motion is a hallmark of unstable air, as it enhances the potential for convection and contributes to the development of storm systems. Thunderstorms can also create severe weather phenomena such as heavy rain, hail, and lightning, further emphasizing the connection between unstable air and thunderstorms.

While clear visibility and calm winds are generally associated with stable air conditions, patchy fog can occur in both stable and unstable environments, but it is not as directly linked to the presence of thunderstorms as unstable air is. Thus, the development of thunderstorms is a prime indicator of instability within the atmosphere.