Mesoscale Characteristics Analysis of a Heavy Rainfall along the Yangtze River Regions in Anhui in 2010

The NCEP reanalysis data were used to analyze the heavy rainfall process what occurred along the Yangtze River regions in Anhui from July 12 to 13 in 2010.At the same time,the Doppler weather radar data were used to analyze the mesoscale characteristics in the heavy rainfall progress.The results indicated that the direct reason of heavy rainfall was mesoscale precipitation system excited by cold air.Low-level jet stream provided a steady water vapour and instability-energy.Symmetric instability what caused by the upper-level jet stream made the mesoscale upward motion enhanced.The adverse wind areas and mesoscale cyclones had well relationship with the change of heavy rainfall.