An Analysis of Doppler Radar Echo Feature on Fushun 090621 Hail

Weather background,physical quantities and development characteristics of radar echoes,routine meteorological data and Shenyang Doppler radar data were used to analyze the causes of the hail synoptic process in the east of Fushun on June 21,2009.The results suggested: the hail weather occurred in the surface low pressure zone and the southeast quadrant of the bottom of the 500 hPa cold eddy,which was formed by 500 hPa cold eddy mobiling and triggering the low-level shear line.Before the hail,there were unstable energy and water vapor transportation in the atmosphere.Moreover,the intrusion of cold air at 850 hPa aggravated the unstable of atmospheric stratification,and promoted the release of unstable energy to produce hail weather.And High-low altitude jets went together to provide dynamic conditions for the severe convection developing.According to Doppler radar data analysis,strong convective weather that reflected the characteristics of arciform,hook-shaped and v-shaped gap during the development of prosperity with strong echo zone 50-60 dBz,the largest echo 67dBz consisted of several convective monomers.Meridional velocity processed convergence zone and head wind zone.The dead wind zone's appearing 1h before the hail was a strong signal.It was 20-40 km/m2 of liquid-water and 50 km/m2 of the largest vertical liquid-water content about the hail.The convection monomer echo top could arrive 9-11 km in a hail.Wind direction and wind speed of vertical wind profile represented greater vertical shear.