Low Clouds Cumulus clouds are low. They appear puffy, and look like cotton balls, popcorn, or cauliflower. Stratus clouds are low. They are light or dark gray and generally uniform in appearance. They cover most of the sky.
Stratocumulus clouds are low, with irregular masses.
They are rolling or puffy in appearance, sometimes with space between the clouds. Cumulonimbus clouds are large clouds with dark bases and tall, billowing towers. They can have sharp, well defined edges with sometimes an anvil shape at the top. Precipitation can obscure the base of the clouds. They can be accompanied by thunder.