Cumulonimbus Cluster
Small bright cloud cells and cell complexes, accompanying convection and unstable processes.
Cluster of Cumulonimbi can be found in an unstable environment where dynamical forcing in the atmosphere plays a role as an additional triggering effect. Cumulonimbus cluster can occur in any unstable air mass: in a cold air mass behind a polar Cold Front, in the frontal zone of a polar front and in warm air of a thermal ridge. Cb Cluster in Warm Air, which are the subject of this investigation, are mesoscale cloud phenomena with an average diameter of 200 km. Over land they start to be generated when the surface temperature enhanced by insolation becomes sufficient to trigger convection. They dissolve during night, and this is one of the main characteristics to differentiate them from Mesoscale Convective System which can exist during the night. Cb Cluster are often embedded in cellular low cloudiness of other types.