The Characteristics Of Atmospheric Structure And Echo Evolution Mechanism Of Strong Convective Precipitation

The sudden severe convective weather is a key problem for prediction of disastrous weather. This paper discussed the advantages of potential temperature expressing the atmospheric heat structural. On the basis of conventional weather analysis, using the data of conventional meteorological data, the FNL data, doppler weather radar data, FY-2meteorological satellite data, etc, take the July2nd to3rd2012of the Nanjing area and July7th to10th,2013in Chengdu area of convectional precipitation weather for example, using the wind vector potential temperature (V-30) plot, the structural characteristics of the atmospheric instability and dynamic lifting and water vapor before convective weather appeared were analyzed.We discovered that the lower level cold stratus has the condensing cumulonimbus effect, makes the extraordinary increase in precipitation. It is the omen information of July3rd,2012rainstorm in Nanjing; Extremely large and thick, water vapor convergence layer has been extended to200hPa, close to the tropopause, and flow in the roll under the condition of convective clouds, warm clouds, cold clouds appear alternately atmospheric vertical structure, is the omen information of July9th,2013rainstorm of Chengdu. Using the Doppler radar PPI data the formation and evolution of the rain were analyzed, the mesoscale cyclone and hail and bow echo of July3rd,2012rainstorm in Nanjing and also the βmesoscale strong convective echo band causing July9th,2013rainstorm in Chengdu were identified, the three-dimensional wind field structure with updraft and downdraft coexisted was revealed, proposed the analysis principle for VCS velocity echo. The coldest cloud’s brightness temperature and area of the mesoscale cloud cluster in satellite cloud picture determine the intensity of the storm and the rain area.Research result shows that the structure contains the physical mechanism. The wind vector potential temperature chart helps to reveal the omen information of atmospheric structure, promote the potential convective forecasting; echo intensity and velocity of Doppler radar could monitor the evolution of three-dimensional structures, provides more details in order to improve the nowcasting.