A C-band dual polarization radar has observed wintertime thunderclouds peculiar to the coast area of the Sea of Japan. At the moment of lightning, graupel identified by low ZDR and high ZH is seen to be rapidly lifted up to 3 km height, corresponding to the -10 ¿C level. In addition, the graupel encounters small ice crystals with high ZDR and low ZH above this height. This situation satisfies the recent thunderstorm electrification theory. The PPI radar display reveals a band-like structure for this type of wintertime thunderclouds. In this structure, the small ice crystals are primarily seen on the windward side of the clouds. Part of the ice crystals mixed with the graupel seems to be brought from the back of an adjacent cloud, which precedes the thundercloud carrying the graupel. ¿ American Geophysical Union 1991