Convective clouds and storms represent one of the most important and challenging problems for forecasters. The severe local storms and deep convective clouds are characterized by the enhanced transport of heat and moisture in the upper layers, very strong self-organized flow fields, very complex microphysical transformations and stratospheric penetrations, and rapid evolution and dissipation processes. The precipitation processes are activated in very limited time intervals and space, and their intensities are manifested by a large natural variability. Supercell storms are perhaps the most violent of all convective storm types and are capable of producing damaging winds, large hail, and weak to violent tornadoes. They are most common during the spring across the mid-latitudes when moderate to strong atmospheric wind fields, vertical wind shear, and instability are present. The degree and vertical distribution of moisture, instability, lift, and especially wind shear have a profound influence on convective storm types. It is generally recognized that the environmental buoyancy and vertical wind shear have an important effect on the characteristics of convective storms. Much of our understanding of the sensitivity of convective storms to these environment parameters has been derived from modeling studies that tested a variety of, but often idealized, environmental conditions.

According to the passage, which of the following is NOT a characteristic of convective storms?

A. increased movement of heat and moisture
B. powerful flow-fields
C. intricate transformations and penetrations
D. rapid evolution processes
E. persistence over certain geographical areas