Discussion: There are three stages of a thunderstorm: the cumulus stage, the mature cumulus stage, and the dissipating stage. Each stage are defined by certain characteristics and are outlined below.
Air that is warmer than its environment will start to rise by convection during this stage. As this warm, moist air rises, it will cool and condense, thus forming a cumulus cloud. The updraft is very strong at this point so as the small raindrops try to fall, they get suspended and pushed up even further in the cloud. The raindrops begin to form larger raindrops as they collide with one another. The cloud continues to grow vertically and eventually reaches a height above the freezing level. At this level, supercooled water molecules exist, meaning that there is liquid water that is below the freezing point of liquid water. This allow for the water droplets to grow very large and fast. When they become large enough, they fall from the cloud and start the initiation of a cool downdraft. This leads to the second stage.
2) Mature Stage
This stage is characterized by the presence of both updrafts and downdrafts. As the air descends to the ground, evaporative cooling takes place. This is because the air below the cloud is still relatively dry which allows for the water molecules to evaporate. This cools the atmosphere. Sometimes this process can cool the atmosphere by as much as 20 degrees in 30 minutes. Evaporative cooling acts to further strengthen the downdraft. When the downdraft hits the ground, it has nowhere to go so it spreads out in all directions. This can sometimes cause minor damage to trees and houses. The cloud will continue to grow vertically as there is still a very strong updraft. The strong updraft will continue to push some of the water molecules way up into the higher parts of the cloud. This is usually when the anvil shaped cloud becomes visible. Hail is also formed at this point and intense cloud-to-ground lightning can be seen. As long as the updraft remains strong, hail will continue to grow in size. Once the hail is too large to be supported by the updraft, it falls to the ground. The downdraft will eventually cut off the updraft which is supplying the storm with the warm and moist air. When this occurs, the final stage commences.
3) Dissipating Stage
At this stage, the downdraft is prominent. The downdraft continues to cut off the warm and moist air that is needed for the storm to maintain itself. The anvil that is seen during the mature stage starts to flatten out as the storm continues to weaken and the latent heat, which is the energy that is released when the water vapor transitions to liquid droplets, process has been cut off. The once towering cumulonimbus cloud then turns into wispy, non-threatening clouds.
This whole process takes about an hour but does vary with each storm. In some severe thunderstorms, the process can take several hours since the updraft is much stronger and can maintain the storm for a longer period of time. If the updraft is slanted, meaning that the thunderstorm is tilted as the height increases, as in the case for a severe thunderstorm, then the rain-cooled air cannot cut off the warm, moist air that is being brought up into the storm. This can cause the storm to maintain its strength for even longer.
Credit: North Carolina Climate Office
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@2019 Meteorologist Corey Clay