Particle discrimination in hailstorms

The occurence of the different kinds of precipitation particles inside severe storms is of great interest for deducing the basic cloud physical processes. This is essential for a better understanding of desastrous weather phenomena like hail or wind damages. In this paper we present a case study of a hailstorm observed in Southern Germany during the CLEOPATRA (Cloud experiment Oberpfaffenhofen and cloud transports) experiment performed in summer 1992 (Meischner et al., 1992). The DLR polarimetric C-band radar data are analysed for their potential for hydrometeor discrimination. We demonstrate that it is possible to distinguish zones of significantly different ranges of differential reflectivity and depolarization ratio. These zones are attributed to the different kinds of hydrometeors like graupel, dry or we hail, raindrops as well as mixed phase precipitation. Implications for microphysical growth processes are also demonstrated. The measurement emphasize the role of recirculation processes for hail growth. Zones of wet growing hail are shown to be present in the main storm core aloft.