Analysis Of Rainstorm And Application About Forecast And Trace Of Doppler Radar During A Cold Cyclone On North China

Convective weathers affected by cold cyclone often occurred on North China Plain during early summer, during which short-time rainstorm, heavy wind and local hailstone happened We studied data of NCAR/NCEP and products about Doppler radars of Beijing and Tianjin on this kind of weather, then concluded a forecasting model with the characters of atmospheric circulation and the points of Radar products on short time forecast.The tilted trough became forward from backward, because of the cold air on higher level moving above the warm tongue area near grand during a cold cyclone on North China.The Dry intrusion on middle and high level of troposphere helped storm developing; The shear line of wind near ground was the indispensability condition touching off the storm growing; The convective weather happened in the area of cyclonic wind on the north of shear line of wind before cold front. The vapour of rainstorm was carried by South East wind on Shandong peninsula during lower level, at the same time the convergence of horizontal wind speed on lower lever helped the water convergence creating; The storm developed with stronger CAPE and more obvious unstable stratification during this period of summer season.About forecasting and tracing of storm’ movement by study Radar products,there were some differs of angle between the prediction and the actual path of storms,and special unexpected change with storm tracking information.After we studied the reasons of these information, we concluded the value of storm tracking info were correlated with those conditions of the stability about storm movement and the different periods of storm. Further more we could forecast the locus of disaster of storm after judging the character and development of different storms.All these could help the actual forecast.