FAA Ground School Practice Test

Which cloud types are indicators of convective turbulence?

1. Cirrostratus clouds

2. Stratoform clouds

3. Towering cumulus clouds

4. Nimbostratus clouds

The correct answer is: Towering cumulus clouds

Towering cumulus clouds are significant indicators of convective turbulence because they are associated with strong updrafts and downdrafts, which are characteristic of convective systems. These clouds form when warm, moist air rises rapidly and cools, leading to the development of vertical cloud structure. The intense convective activity within towering cumulus clouds can produce turbulence that affects both the aircraft during flight and the surrounding weather conditions. The other cloud types listed do not typically indicate convective turbulence. Cirrostratus clouds are high-altitude clouds that form from the spread of ice crystals and are generally associated with stable atmospheric conditions. Stratoform clouds, which include stratus and stratocumulus, usually indicate stable air and are not indicative of significant vertical motion or turbulence. Nimbostratus clouds often bring widespread, steady precipitation and indicate a stable environment rather than turbulent conditions. Therefore, towering cumulus clouds are the most direct signal of convective turbulence in the atmosphere.