Analysis on dual polarization radar observations of a heavy snowstorm event in Anhui in the beginning of January 2018

A heavy snowstorm event, with high precipitation intensity and maximum cumulative precipitation of more than 71 mm, occurred in Anhui Province from January 3 to 5 in 2018. After snowfall, icing, freezing rain and snow disaster were generated under low temperature at the surface and in the low-level. Maximum snow depth reached greater than 40 cm. Using routine observational data, we have firstly analyzed the observations of this heavy snowstorm event, and then judged the melting layer height and the phase of precipitation particle using dual polarization radar data. The results show that (1) this event is well observed and recorded by Fuyang dual polarization radar, whose low value area of the zero order lag correlation coefficient (CC) coincides mostly with the melting layer. The product such as basic reflectivity factor (dBZ), CC and differential reflectivity (ZDR) can be used to distinguish the melting layer height, and to infer the phase of precipitation particle. (2) The melting layer (ML) and hydro classification (HCL) products from dual polarization radar are based on fuzzy logic method, whose melting layer height and precipitation particle phase coincide with the ones from subjective judgment made by using basic products from dual polarization radar, conforming to the observations. (3) The ML and HCL products from dual polarization radar can be certainly served as a reference for detecting and judging of precipitation particles in winter.