Production and verification of nowcasts generated with different parameterizations for different convective storm types

The aim of this work was to determine whether it is necessary to optimize a nowcast scheme for use with different convective storm types. Nowcasts have been produced using the K-means cluster scheme within WDSS-II and varying parameters within the scheme. The nowcasts were completed for four cases each of supercells, QLCS, multicells and bow echoes. The variations in the scheme include changing the range of values to which the advection component responds, the spatial scales over which the clustering is performed, and the field upon which the nowcast operates. Not only were reflectivity fields used to create nowcasts, they were also performed on differential reflectivity (ZDR) and specific differential phase shift (KDP). Verification of forecasts was performed using standard categorical statistics and the Procrustes Analysis Verification scheme that is designed to assess whether forecasts of convective storms contain errors in location, size, shape, orientation and intensity. Results suggest that the quality of the nowcasts is affected by parameter selection, and different parameters are suitable for some of the storm types, while some storm types are insensitive to nowcast choices.