by KNMI and DHMZ

Common Remarks

Clusters of Cumulonimbi can be found in an unstable environment where dynamical forcing in the atmosphere plays a role as an additional triggering effect. Cumulonimbus clusters can occur in any unstable air mass; in a cold air mass behind a polar Cold Front (see Enhanced Cumulus and Comma ), in the frontal zone of a polar front (see Conceptual Model Front Intensification By Jet Crossing or the Conceptual Models Cold Front and Occlusion: Warm Comveyor Belt Type ) and in warm air of a thermal ridge as dealt with in this chapter.