FAA Ground School Practice Test

Which cloud type is primarily responsible for creating severe weather conditions?

1. Stratus

2. Cumulonimbus

3. Nimbostratus

4. Cumulus

The correct answer is: Cumulonimbus

Cumulonimbus clouds are the primary cloud type responsible for severe weather conditions. These towering, dense clouds can extend high into the atmosphere and are associated with thunderstorms, heavy precipitation, lightning, hail, and even tornado formation. The vertical development of cumulonimbus clouds allows them to reach the upper levels of the atmosphere, where temperature and moisture differences can generate powerful updrafts and downbursts. The classification of these clouds is based on their structure and the atmospheric conditions they represent. Cumulonimbus clouds typically feature anvil-shaped tops that may indicate the potential for severe weather. In contrast, the other cloud types listed indicate different weather phenomena that generally do not produce severe conditions: stratus clouds are low, gray clouds that typically produce overcast skies without significant precipitation, nimbostratus clouds are thick, dark clouds associated with steady, continuous rain, and cumulus clouds are the puffy, white clouds usually seen in fair weather and do not have the same severe weather potential as cumulonimbus clouds.