Cumulus clouds are large, white, and fluffy with a flat base and rounded tops. They are often associated with fair weather but can also develop into towering cumulonimbus clouds, which bring thunderstorms. Stratocumulus clouds are low-level clouds that appear as a layer or patchy sheet with a wavy or lumpy appearance. Stratus clouds are low-level, uniform, and featureless clouds that often cover the entire sky, creating a gray or overcast appearance. Cirrus clouds are high-level clouds that are thin, wispy, and often appear as white streaks or filaments. Altostratus clouds are mid-level clouds that are gray or blue-gray and often cover the entire sky, blocking out the sun but not producing precipitation.