Clouds of Vertical Extent

-Cumulus (Cu) A cloud in the form of individual, detached domes or towers that are usually quite dense and well-defined. Characterized by flat bases with bulging cauliflower like upper part. Generally fair weather clouds that look like cotton puffs. These clouds indicate rising air motions (convection). Bases are generally 5,000 feet or below. (Cumulus Humilis)

-Cumulonimbus (Cb) Large, towering (precipitating) cumulus clouds accompanied by thunder, lightning and rain. Bases are generally between 2,000 (tropical environments) and 10,000 feet (more arid environments); tops as high as 60,000 to 70,000 feet in more severe storms. Cirrus clouds, at top of parent cumulonimbus cloud, can be carried hundreds of miles away from the parent cloud by upper level winds near the tropopause. From a distance, the top of the cumulonimbus may look like a blacksmith's anvil.