Analysis of the environment condition and evolution characteristic for a mixture strong convective event

A widespread convection event with multiple convection types is analyzed by using sounding observation data, NCEP reanalysis data and Doppler weather radar products, which occurred in Hunan province on 3rd April 2015. The results are shown as follows. Atmospheric circulation had clear adjustment before the occurrence of strong convection weather event. Strengthening of the low level southwest jet and involvement of cold dry air in middle layer provide favorable environmental conditions for the convective weather. Suction effect of upper-level divergence and low-level convergence, as well as the cyclonic shear and wet baroclinic forcing effects are the main reasons for mixed convection and extreme precipitation in northeast Hunan province. Caused by the combined effect of warm and wet air being uplifted above inversion layer and strong vertical wind shear, hailstones appear in Hanshou station, which have the elevated thunderstorm characteristic. Due to the high thermal instability in Xinhuang, hailstones occur frequently in the intersection of cold and warm air. Radar product analysis shows that hail and thunderstorm winds are charactered by typical three-body scattering and middle strong high-level divergence, while short-time rain storm is charactered by low-centroid high efficient precipitation and train effect.