Which condition indicates unstable air?

The condition that indicates unstable air is the formation of convective currents. In meteorology, unstable air is characterized by the tendency for air parcels to rise rapidly when they are warmer than the surrounding air. This rising motion leads to the development of convective currents, which can contribute to turbulence and the formation of cumuliform clouds, such as thunderstorms.

When air is unstable, it allows for a greater mixing of air layers, which is vital for the development of weather phenomena. In contrast, stable air is associated with less turbulent conditions, where layers of air are stratified and resist vertical motion. Therefore, the presence of convective currents is a clear indicator of instability, making this the correct choice.

High humidity levels and good visibility can exist in both stable and unstable air, as humidity alone does not determine atmospheric stability. Strong temperature inversions typically indicate stable air conditions, where a layer of warm air traps cooler air at lower altitudes, preventing vertical mixing. This suggests a stable rather than unstable environment.