Cause Analysis of A Severe Convective Weather in Northwestern Fujian

Formation mechanism of the severe convective weather in Northwestern Fujian on 23 March 2013 is analyzed,according to the evolution characteristics of weather situation, physical quantity fields and radar echoes, with data from conventional observation, NCEP reanalysis data, data of regional automatic stations and Doppler Radar observations. Results show that, this event occurs in warm sector ahead of the stationary front, meanwhile, the high level weak cold air intrudes. All of these provide good environment field for the weather process, which are good water vapour transport, high instability energy, strong vertical wind shear, allocation of lower level convergence and upper level divergence, and su rface meso-scale convergence line. The strong radar echo cell moves eastward and develops, leading to hail and thunderstorm. The reflectivity factor displays features of supercell storm at 15:45, such as hook echo, mesocyclone, low layer weak echo region, middle layer echo pendency structure, and rich vertically integrated liquid water.