The comparative analysis of mesoscale characteristics for two short-term heavy precipitation processes

Using the conventional observation data, satellite data, radar and automatic station data to analyze the two short-term heavy precipitation processes, which happened on June 8, 2012( Process Ⅰ) and July 1( processⅡ) in Heilongjiang Province. The two processes are both affected by low vortex system, and the cold air invaded into the warm area cause short-term heavy precipitation. The differences of these two processes are that, in the processⅠ,a supercell storm is triggered at warm sector in the front of cold front,it shows convective cloud development before the cold front, overall appear zonal, every cloud isolated in the satellite images. The characteristics of radar echo shows the supercell storm developed at the convective echo sequence, while precipitation is local and strong. In the processⅡ, a squall line cloud is triggered by cold front, and the characteristic of radar echo is the typical strip squall line echo,corresponding to the zonal distribution of precipitation and affecting large area.