Towards nowcasting of winter precipitation: The Black Ice Event in Berlin 2014

Prediction of winter precipitation is challenging because besides its amount also its variable phase might have a strong impact on people, transportation, and infrastructure in general. We combine a bulk microphysics numerical weather prediction with a 1D spectral bin microphysical model, which explicitely treats the processes of melting, ice nucleation and refreezing as a first step towards a potential nowcasting application. Polarimetric weather radar observations from the German national meteorological service (DWD) are used to evaluate the approach. The potential of the strategy is demonstrated by its application to the black ice event occurring in Berlin, Germany, on 20 January 2014. The methodology is able to clearly identify the classical mechanism leading to freezing rain at the surface, which might be exploited in future nowcasting algorithms