Analysis on an Application of Doppler Radar Echo in a Heavy Rain

Based on the Doppler radar echo data and conventional sounding data as well as hourly rainfall data,a regional heavy rain event occurred in eastern Hebei plain on July 18,2007 is analyzed.The results show that the southward and eastward moving of a meso-α-scale shear over low-level and the convergence line are the main influential systems.The convergence line is caused by both the maintaining southwest-moist-jet before the rainfall and the surface layer easterly airflow over eastern Hebei plain.Under the unstable stratification condition,the perturbation of meso-scale low-level jet of upstream radar stations is of significance for downstream stations' rainfall forecasting.