Conventional Analysis on a Heavy or Torrential Rain Weather Process
【摘要】：[Objective] The research aimed to analyze a turning weather process in Binzhou City of Shandong Province in midsummer of 2010.[Method] Started from the short-term forecast ideas,the formation reason of heavy or torrential rain and local heavy rainstorm in Binzhou City during 4-5 August,2010 was analyzed from the circulation situation,physical quantity field,radar echo and so on.[Result] The westerly trough and cold air were the trigger mechanisms of precipitation.The warm wet air flow at the edge of subtropical high and the high-altitude low trough were the main systems of precipitation.It was the typical precipitation process that the northwest of subtropical high overlapped with the westerly trough.In the prior period,the high temperature continued.The cold air at 500 hPa made the convection strengthen.It was the main reason that the local precipitation was strong.In the forecast of rainstorm,the specific humidity,K index and SI index were the good physical quantities and reference indexes.In the formation process of rainstorm,K index had the increasing process.When the rainstorm finished,or the rain intensity weakened,K index decreased obviously.SI index indicated the development of convective precipitation.The radar echo analysis found that the mesocyclone appeared in the process for a short time.For it weakened quickly and disappeared in the shift process,the strong precipitation and gale were formed in the west of Binzou,but the hail wasn't generated.[Conclusion] The research provided the experience for the forecast of such weather in future.