Quantitative Precipitation Nowcasting based on X-band Multi-parameter Radar and JMA C-band Conventional Radar Measurments

Abstract

Urban rivers causing urban floods have so quick response that nowcasting is required. The rainfall intensity estimation using specific differential phase of multi-parameter radar provides more quantitative rainfall estimate than reflectivity factor. There are two problems in the nowcasting; (1)X-band radar cannot obtain rainfall information behind strong rainfall, (2)The range of single X-band radar is not large enough to nowcast up to 1 hour. We composite MP-radar data with C-band radar data to fill the missing region and to obtain the data outside the range. The MP-JMA composite data had a good correlation with surface raingauges. Our results show that out nowcasting system provides more quantitative precipitation forecasting than that using C-band conventional radar.