Abstract:Based on the NCEP/NCAR reanalysis data and the 30 year average precipitation data from National Meteorological Information Center, in terms of the dynamic diagnosis and analysis, the heavy rainfall during June-July 2007 in the Huaihe Valley has been analyzed. The results are as follows: the vertical structure of the circulation pattern corresponded well with the precipitation in the Huaihe Valley. During the heavy rainfall, the double blocking highs, which were located in the Okhotsk Sea and Ural Mountain respectively, provided the favorable condition for the consistent rainfall. The divergence was positive in the upper level (200 hPa) and negative in the lower lever (850 hPa) of the South Asia high. The pumping of the intense field was in favor of the heavy rainfall. The South Asia high and the 500 hPa West Pacific subtropical anticyclone moved toward each other. The potential vorticity (PV) could explain the activity of the cold air clearly. Before the occurrence of the heavy rainfall, there were obvious positive PV anomalies extending from the high latitude to the low latitude. Heating revealed that the large centers of the apparent heat source and moist sink corresponded well with the heavy rainfall center of the same period of the time.