X-band Dual-Polarization Radar Observations of the Supercell Storm that Generated an F3 Tornado on 6 May 2012 in Ibaraki Prefecture, Japan

X-band dual-polarization (multi-parameter) radars were used to observe a supercell storm that generated an F3 tornado in Ibaraki Prefecture, Japan on 6 May 2012. The observed data collected for this storm clearly exhibited the typical polarimetric features of a supercell storm, such as the Z(DR) (differential reflectivity) arc, Z(DR) column, and the K-DP (specific differential phase) column, as well as their time evolution. The Z(DR) arc emerged at 10 to 15 min before the tornadogenesis. The Z(DR) column appeared approximately 1 h before the formation of the Z(DR) arc and was intermittent until tornadogenesis. As the Z(DR) arc appeared, the column became tall and stable and lasted until the dissipation of the tornado. These Z(DR) signatures of the supercell storm persisted for approximately half an hour.