Clouds composed of water droplets that exhibit vertical development. The density of the droplets often blocks sunlight, casting shadows on the earth's surface. With increasing vertical height, they are often associated with convection. Bases of these clouds are generally no more than 3,000 feet above the ground, but they can develop past the troposphere in both temperate and tropical latitudes. They are classified as low clouds, and include all varieties of cumulus and cumulonimbus. The opposite in type are the horizontal development of stratiform clouds.