These three MAP events are associated with different flow regimes: stable statification with blocked flow during IOP8, and unstable or potentially unstable conditions with flow over during IOP2a and IOP3.
In response to these different flow regimes, the numerical simulations exhibit a contrasted behaviour in the microphysical structure of the clouds. In the case of IOP8, cloud tops hardly reach the height of 5 km and the prominant microphysical processes are typical of stratiform clouds: coalescence below the freezing level, and vapor deposition above. In the case of IOP2a and IOP3, the cloud systems are much deeper and the contribution of ice microphysics is more important and more active. In both cases the dominant microphysical process above the freezing level is clearly the riming but only the case of IOP2a produces a thick layer of graupel and provides the conditions for the generation of hail in a significant amount. These results are in close agreement with the observations of the polarimetric radar S-Pol.