A New Hail Detection Algorithm of Hail Diagnostic Parameters Based on 3D Mosaicing Data of Multi-Radar

For the purposes of improving the detection limitations in single-radar cones-of silence,far ranges from one radar,terrain blocking areas and integrating with Near-Storm-Environment(NSE) data from mesoscale numerical models,3D grid reflectivity data mosaicing application are developed using the local space interpolation on a latitude and longitude-height grid with approximately 3 km×3 km×0.5 km.Using the 3D grids of multiple-radar,a new hail detection algorithm integrating is developed through the grid VIL,grid SHI,grid POH and grid POSH,and data(at the heights of 0℃ and-20℃) derived from mesoscale numerical model.The evaluation databases for the WSR-88D hail detection algorithm have been built using the hail observation data of 504 hail prevention spots in Guizhou and Doppler radar data of Guiyang and Zunyi during 8 severe hail events from 2005 to 2006.For the determining threshold of grid VIL density,the relationship between the VOD(VIL of the day) which is suitable for Guizhou area and the freezing level,has been established.Finally,POSH algorithm has been improved through the optimization WTSM(Warning Threshold Selection Model).These new hail diagnostic parameters have well identified in a severe hail storm in north-western Guizhou.