Contrast Analysis of Two Torrential Rain Events in Kunming

Based on NCEP/NCAR 1°×1° reanalysis data and various dense observation data，torrential rain occurred in Kunming on 18～19 July 2013 and 19～20 July 2017 are diagnosed. The results show that there exist different and general characteristics among these two torrential rain. The general characteristics of these two torrential rain are as follows: the mainly inpact large scale system of these torrential rain are convergence zone between the Tibetan high and the West Pacific subtropical high in 500 hPa (the two high convergence zone)and shear line in 700 hPa. The vapor from South China Sea and Bay of Bengal converged at the two high convergence zone. Deep moisture convergence layer caused by the two high convergence zone are main vapor characteristics in these torrential rain weather. Warm and wet unstable air convergence can lead to the grow and development of the meso-βscale convective system(M_βCS). The heavy rain occured in the denser gradient of TBB isoline areas. The short-time heavy rainfall which caused by the evolution of the meso-βscale convective cloud happened. The different characteristics of these two torrential rain are as follows: due to the effect of the Northwest Pacific Tropical Cyclone named Cimaron，moisture convergence zones maintained longer time in 2013’s rainfall than 2017’s. The heavy rain which caused by stronger ascending motion lasted for 17 hours in 2013. Before the heavy precipitation starts，the accumulation of convection unstable energy existed. The convective rainfall dominated in 2017’s heavy rain and the rainfall intensity was highly 70 millimeter per hour.