Object-based analysis of simulated thunderstorms in Switzerland: application and validation of automated thunderstorm tracking with simulation data

Abstract. We present a feasibility study for an object-based method to characterise thunderstorm properties in simulation data from convection-permitting weather models. An existing tracker, the Thunderstorm Identification, Tracking, Analysis and Nowcasting (TITAN) algorithm, was applied thunderstorms simulated by Advanced Research Weather Forecasting (AR-WRF) model at resolution domain centred on Switzerland. Three WRF microphysics parameterisations were tested. The results are compared independent radar-based observations of derived using MeteoSwiss Thunderstorms Radar Tracking (TRT) algorithm. TRT specifically designed track over complex Alpine topography approach produces statistics that can be observation data. indicate simulations underestimated occurrence severe very large hail observations. Other properties, including number storm cells per day, geographical hotspots, diurnal cycles, movement directions velocities, provide reasonable match observations, which shows technique characterisation terrain.