Characteristic analysis of a short-range snowstorm event in Wuhan based on ground raindrop spectra data

Data from Thies Clima laser precipitation monitor (TCLMP) and observations from intensive artificial weather stations were used to preliminarily analyze evolution characteristics of a short-range snowstorm event occurred on 12 February 2011 in Wuhan. The results show that cumulative snowfall of 5.6 mm by artificial observation is consistent with detecting one by TCLPM. This short-range snowstorm event has experienced three different periods such as rainfall, sleet and snowfall, and the different droplet spectra characteristics corresponding with three precipitation types have been monitored by TCLMP. During rainfall period, particle falling velocity is faster but particle diameter is smaller, while during snowfall period, particle falling velocity is slower but particle diameter is bigger. At the same time, the remarkable change of raindrop size distribution patterns in three periods have been monitored, and the patterns experience a process from unimodal spectrum to undulation and then multimodal spectrum. Furthermore, both spectrum width and number concentration are significantly in increase trend. Rainfall intensity has a positive correlation with both reflectivity factor and massweighted mean diameter of particle, namely, higher rainfall intensity corresponds with larger reflectivity factor and bigger raindrops average diameter, and vice versa.