Development of a radar-based Hail-Detection-Product

At the moment, a tool for the detection and display of severe weather events related to convective phenomena is being developed at the KNMI. Radar reflectivity and Doppler winds will be the primary source of information, and it will be complemented with other observations and data from numerical weather prediction (NWP) models. The KNMI operates two Gematronik C-band Doppler radars which are performing low-elevation volume scans every 5 minutes and extensive volume scans every 15 minutes. From these scans, a ``constant-altitude plan-position indicator'' (CAPPI) of the radar reflectivity and an echotop product, which is roughly an indicator of the cloud-top heights, are extracted. Ground clutter is removed from the CAPPI image using a statistical method. The first new product under consideration is a tool for the detection of summer hail.