Information: - Cumulus congestus clouds, also known as towering cumulus, are a form of cumulus cloud that can be based in the low or middle height ranges. They achieve considerable vertical development (family D2) in areas of deep, moist convection. They are an intermediate stage between cumulus mediocris and cumulonimbus. - A thunderstorm, also known as an electrical storm, lightning storm, or thundershower, is a storm characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere, known as thunder. Thunderstorms occur in association with a type of cloud known as a cumulonimbus. They are usually accompanied by strong winds, heavy rain, and sometimes snow, sleet, hail, or, in contrast, no precipitation at all. Thunderstorms may line up in a series or become a rainband, known as a squall line. Strong or severe thunderstorms, known as supercells, rotate as do cyclones. While most thunderstorms move with the mean wind flow through the layer of the troposphere that they occupy, vertical wind shear sometimes causes a deviation in their course at a right angle to the wind shear direction. - A cumulonimbus incus (Latin "incus", "anvil") also known as an anvil cloud is a cumulonimbus cloud which has reached the level of stratospheric stability and has formed the characteristic flat, anvil-top shape. A cumulonimbus incus means that the thunderstorm is in its mature stage, succeeding the preceding cumulonimbus calvus stage. Cumulonimbus capillatus is a sub-form of cumulonimbus incus. - Atmospheric instability is a condition where the Earth's atmosphere is generally considered to be unstable and as a result the weather is subjected to a high degree of variability through distance and time. Atmospheric stability is a measure of the atmosphere's tendency to encourage or deter vertical motion, and vertical motion is directly correlated to different types of weather systems and their severity. In unstable conditions, a lifted thing, such as a parcel of air will be warmer than the surrounding air at altitude. Because it is warmer, it is less dense and is prone to further ascent. - Latin (Latin: ) is a classical language belonging to the Italic branch of the Indo-European languages. The Latin alphabet is derived from the Etruscan and Greek alphabets. - Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitatedthat is, become heavy enough to fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides suitable conditions for many types of ecosystems, as well as water for hydroelectric power plants and crop irrigation. - Water is a transparent and nearly colorless chemical substance that is the main constituent of Earth's streams, lakes, and oceans, and the fluids of most living organisms. Its chemical formula is HO, meaning that its molecule contains one oxygen and two hydrogen atoms, that are connected by covalent bonds. Water strictly refers to the liquid state of that substance, that prevails at standard ambient temperature and pressure; but it often refers also to its solid state (ice) or its gaseous state (steam or water vapor). It also occurs in nature as snow, glaciers, ice packs and icebergs, clouds, fog, dew, aquifers, and atmospheric humidity. - Cumulonimbus calvus is a moderately tall cumulonimbus cloud which is capable of precipitation , but has not yet reached the tropopause , which is the height of stratospheric stability where it forms into a Cumulonimbus Capillatus ( fibrous - top ) or cumulonimbus incus ( anvil - top ) . Cumulonimbus calvus clouds develop from cumulus congestus , and its further development under auspicious conditions will result in cumulonimbus incus . This cloud consists mainly of water droplets . By definition of cumulonimbus cloud , at its top water droplets are transformed into ice crystals , but for cumulonimbus calvus content of ice crystals is small and freezing is in early stage , so cloud top still looks round and puffy . Cumulonimbus calvus is characterized by distinctive ( between other types of cumulonimbus cloud ) rounded shape and relatively sharp edges of its top area , unlike cumulonimbus incus or cumulonimbus capillatus , which have cirriform tops . Developing cumulonimbus calvus loses sharp outlines of the top as more water droplets transform into ice crystals . Strong updrafts may form pileus or thin vertical stripes protruding upwards out of the cloud . When upper part of the cloud freezes to greater extent and clearly visible cirriforms appears , cumulonimbus calvus turns into another species of cumulonimbus . Cumulonimbus calvus arcus is a sub-type of cumulonimbus calvus , which has arcus cloud ahead of cloud 's front . - A supercell is a thunderstorm that is characterized by the presence of a mesocyclone: a deep, persistently rotating updraft. For this reason, these storms are sometimes referred to as rotating thunderstorms. Of the four classifications of thunderstorms (supercell, squall line, multi-cell, and single-cell), supercells are the overall least common and have the potential to be the most severe. Supercells are often isolated from other thunderstorms, and can dominate the local weather up to away. - Cumulonimbus, from the Latin cumulus ("heap") and nimbus ("rainstorm", "storm cloud"), is a dense towering vertical cloud associated with thunderstorms and atmospheric instability, forming from water vapor carried by powerful upward air currents. If observed during a storm, these clouds may be referred to as thunderheads. Cumulonimbus can form alone, in clusters, or along cold front squall lines. These clouds are capable of producing lightning and other dangerous severe weather, such as tornadoes. Cumulonimbus progress from overdeveloped cumulus congestus clouds and may further develop as part of a supercell. Cumulonimbus is abbreviated Cb and are designated in the D2 family. - Lightning is a sudden electrostatic discharge that occurs during an electrical storm. This discharge occurs between electrically charged regions of a cloud (called intra-cloud lightning or IC), between two clouds (CC lightning), or between a cloud and the ground (CG lightning). The charged regions in the atmosphere temporarily equalize themselves through this discharge referred to as a "strike" if it hits an object on the ground, and a flash, if it occurs within a cloud. Lightning causes light in the form of plasma, and sound in the form of thunder. Lightning may be seen and not heard when it occurs at a distance too great for the sound to carry as far as the light from the strike or flash. - A tornado is a violently rotating column of air that spins while in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. They are often referred to as twisters, whirlwinds or cyclones, although the word cyclone is used in meteorology to name any closed low pressure circulation. Tornadoes come in many shapes and sizes, but they are typically in the form of a visible condensation funnel originating from the base of a huge storm cloud, whose narrow end touches the earth and is often encircled by a basal cloud of debris and dust. Most tornadoes have wind speeds less than , are about across, and travel a few miles (several kilometers) before dissipating. The most extreme tornadoes can attain wind speeds of more than , are more than in diameter, and stay on the ground for dozens of miles (more than 100km). - In meteorology, a cloud is an aerosol comprising a visible mass of minute liquid droplets or frozen crystals, both of which are made of water or various chemicals. The droplets or particles are suspended in the atmosphere above the surface of a planetary body. On Earth, clouds are formed by the saturation of air in the homosphere (which includes the troposphere, stratosphere, and mesosphere). The air may be cooled to its dew point by a variety of atmospheric processes or it may gain moisture (usually in the form of water vapor) from an adjacent source. Nephology is the science of clouds which is undertaken in the cloud physics branch of meteorology. Given the information above, choose from the list below the object entity that exhibits the relation 'subclass of' with the subject 'cumulonimbus calvus'. Choices: - alphabet - angle - association - atmosphere - base - branch - cell - chemical formula - cloud - column - condition - convection - course - cumulus cloud - cycle - forming - gravity - hydrogen - ice - language - latin - light - lightning - line - liquid - mass - measure - meteorology - molecule - object - oxygen - part - point - precipitation - pressure - rain - science - series - snow - stability - stage - state - storm - thunderstorm - top - travel - type - variety - water - weather
The answer to this question is:
cumulus cloud