Diagnostic Analysis of Case of One Heavy Rainfall

Based on the weather data and doppler radar and wind profile radar data,analyse case of the heavy rainfall in the evening on July 17,2009.The result showed that continuous transport of the southwest warm and moist air mass and unstable stratification of the STH edge and the cold air adding and the moving direction change of the vortex shear line,these lead to the heavy rainfall.Some strong convective cells merge into squall line in moving process.The rainfall strength and places were related to squall line.There were two rain-mass active periods corresponding to two peak values of rainfall intensity in the time series of the event.Wind profile radar reflected cold air invading time and strength clearly.