Abstract:To better study microphysical characteristics during snowfall process, drop size spectra were collected with an optical disdrometer during the snowstorm event in 11-12 November 2009 in the southern mountainous area of Jinan. The characteristics of the microphysical parameters, the drop size distribution and speed spectral distribution are investigated. It is found that: (1) during the snowstorm, precipitation intensity and number concentration, maximum diameter, and the radar reflectivity factor have positive linear correlations; the precipitation intensity and the maximum diameter has a close relationship; precipitation intensity is decided by the maximum diameter. (2) In the snow process, the spectrum type distributions are of unimodal and index distributions, and the peak value of number concentration is focuses around 0.5 mm. The concentration distribution of each particle size file is inhomogeneous. (3) The velocity spectra are mainly single peak distributions, and the terminal velocity essentially lies in the range of 0.375-2 m·s-1, which almost has no change with the increase of diameter.