American Meteorological Society Certification (AMS) Practice

What type of clouds are described as wispy and feathery, and are primarily composed of ice crystals?

1. Cumulonimbus clouds

2. Cumulus clouds

3. Stratus clouds

4. Cirrus clouds

The correct answer is: Cirrus clouds

The wispy and feathery clouds primarily composed of ice crystals are classified as cirrus clouds. These clouds form at high altitudes where temperatures are low, leading to the formation of ice rather than water droplets. Their appearance is characterized by thin, delicate strands or wisps, often resembling feathers or hair. This distinctive look is due to their formation from the sublimation of ice particles rather than condensation of water vapor, which is more common in lower altitude clouds. Cirrus clouds typically indicate fair weather, though they can also signal a change in the weather, as their presence may precede a warm front. In contrast, other types of clouds, like cumulonimbus, are known for their towering heights and association with severe weather, cumulus clouds are fluffy and indicate fair weather when scattered, and stratus clouds appear as uniform gray layers that cover the sky but do not exhibit the wispy characteristics of cirrus clouds. Thus, cirrus clouds uniquely embody the features described in the question.