Darbas:
cooling by evaporation of the cloud droplets due to entrainment, as well as the falling rain droplets, which accelerate the downdraft even more.Therefore the strongest downdraft can be found within the lower layers of the Cb. At the same time the updraft steadily weakens. The air beneath the cloud base is saturated due to the evaporation of the rain droplets. The downward transported air of the downdraft spreads horizontally after it reaches the surface, which may lead to the development of squall lines. The end of the mature stage is reached when the out flowing dry air cuts off the incoming supply of moist air. During the mature stage of the Cb the weather events are most intense. Although each cell may last only 20 minutes, the cluster may last several hours. These can produce heavy rainfall, downbursts, moderate-sized hail, and occasional weak tornadoes.
2.3.1.3 DISSIPATING STAGE:
The last stage, the dissipating stage, of a Cb is reached when the updrafts
2.4 THUNDERSTORM TYPES
2.4.1 Multi-cells Storms
Although there are times when a thunderstorm consists of just one ordinary cell that transitions through its life cycle and dissipates without additional new cell formation, thunderstorms often form in clusters with numerous cells in various stages of development merging together.
Unlike ordinary single cells, cluster storms can last for several hours producing large hail, damaging winds, flash flooding, and isolated tornados. However this kind of thunderstorm has a very long life span due to the continuous development of new cells, so-called daughter cells. In most cases these daughter cells develop in the right leading part, but sometimes they can also develop on the left side. According to studies, every 5 to 10 minutes such a daughter cell develops. These new cells have a diameter between 3 and 5 km, and the distance to the center of the thunderstorm is approximately 30 km. The daughter cells develop very rapidly and after a short time become the new center of the Multi-Cell Storm (mother cell). This rapid development takes place because the daughter cells develop immediately in front of the mother cell; therefore no kinetic energy is taken away from the cloud. Although the older cells dissolve at the rear part of the complex, the Multi-Cell Storm is still active due to the continuous new development of daughter cells. Investigations have shown that during the life span of a Multi-Cell Storm 30 or more cells can develop. If the sequence of the cells is short the Multi-Cell Storm can change to a Super Cell Storm.
The diagram shows that the daughter cell (n) develops from the so-called
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