What cloud type would typically suggest possible turbulence?

Cumulonimbus clouds are associated with significant turbulence due to their vertical development and strong updrafts and downdrafts. These clouds often form in unstable atmospheric conditions and can produce severe weather phenomena, including thunderstorms, heavy precipitation, and even hail. The turbulence within and around these clouds can be particularly hazardous for aircraft, as the rapid changes in airflow can lead to sudden altitude changes and difficult flying conditions.

In contrast, overcast clouds, stratus clouds, and cumulus clouds generally do not produce the same level of turbulence as cumulonimbus. Overcast clouds typically indicate stable weather conditions. Stratus clouds are low, uniform cloud layers that usually produce light precipitation and are not associated with turbulence. Cumulus clouds, while they may indicate some turbulence depending on their development, do not carry the same intensity of turbulence that is characteristic of cumulonimbus clouds. Thus, when considering which cloud type is most suggestive of possible turbulence, cumulonimbus is the clear choice.