Abstract:

 Falling areas of rainstorm and local heavy rain affected by high trough and North Chain cyclone were summarized. Based on the conventional ground observation data, intensive automatic weather station data, radiosonde data and the European Centre for Medium Range Weather Forecasting (ECMWF) numerical weather prediction products, weather situation, physical quantity field of a rainstorm process on July 29-31, 2011 were analyzed. The results show that forecasting for summer rainstorm considers not only large scale circulation such as high situation, subtropical high intensity and position and so on, but also mesoscale and small scale weather system that is easy to form under favorable large scale circulation background. Generation and development of upper level trough and North China cyclone trigger mesoscale cyclone in this process. Thus, intensity and moving path of mesoscale cyclone are the key factors forecasting this rainstorm process.

Key words: Falling area of heavy rain, Error analysis, Mesoscale system