Simulation of Weather Radar Products for Verification of Model Precipitation

A radar simulation tool (RST) was developed to simulate radar measurements on output data of the Lokal-Modell (LM) of the German Weather Service (Deutscher Wetterdienst, DWD), which is an operational non-hydrostatic weather forecast model on the meso-gamma-scale. Given the characteristics of a radar site (geographic position and hardware parameters) pseudo measurements can be simulated. RST takes into account atmospheric refraction, attenuation by hydrometeors and gases, and backscattering from different types of hydrometeors simulated by the LM. Additionally, the radar antenna function is explicitly considered.

Comparing pseudo radar scans of RST with real radar measurements is an excellent verification method for the model precipitation, because it avoids problems in deriving rain rates from radar measurements and the comparison can be done using the radar data in all three dimensions.

A case study simulating the composite of the Dutch radar network is presented.