Author(s): Cho Thanda Nyunt; Boris Kolar; Yoshihisa Kawahara; Ryota Tsubaki
Keywords: X-band multi-parameter radar; 3D composite rain; Doppler radial wind
Abstract: Analysis of heavy rain in Hiroshima which caused the disastrous debris flow on 20 August, 2014 had been done based on the volume-scanned X-band multi-parameter radar products such as radar reflectivity, Doppler radial wind and radar rain intensity. Three dimensional (3D) high spatial (1 km×1 km) and temporal (5 minute) resolution gridded reflectivity can explain the dynamic motion, developing, mature and dissipating of convective cell. Reflectivity threshold of 25 d BZ (~10 mm/hr) is used to determine the cloud top height and maximum reflectivity presents the convective rain core height. Moreover, the vertical integrated water content in a column above the grid demonstrated the severity of storm index. The surface wind was also successfully derived from scalar integration of Doppler velocities from two radars by using coordinated coplanar (COPLAN) method. The speed and direction of horizontal wind were verified by Japan Meteorological Agency (JMA) operational mesoscale analysis (MANAL) wind updating various observations in weather prediction for mesoscale weather events. By combining observed MP-X radar 2D and 3D products, structural information of convective storms was able to explain clearly.