吉安一次春季典型降水过程分析

Analysis of a Typical Spring Precipitation Process in Ji’an

利用NCEP再分析资料、常规观测资料和雷达资料,重点通过高低层环流形势物理量场和探空资料对吉安一次春季典型降水过程进行分析。结论表明,此次过程是受高空槽、低空切变以及700 hPa西南气流共同作用下形成的一次自北向南的降水过程。对物理量场和探空分析表明,低层有逆温存在,700 hPa有不稳定能量,不稳定条件、水汽条件和动力条件均在700 hPa较为明显,符合高架对流的特征。雷达回波主要为层状积状混合云系的回波,回波强度低于50 dBz,降水过程伴随雷电活动,是一次高架弱对流过程。

Uses NCEP reanalysis data,conventional observation data and radar data,focusing on the physical quantity field of the high and low level circulation situation and radiosonde data to analyze the trip.The conclusion shows that this process is a process of precipitation from north to south formed under the combined action of upper-altitude trough,low-altitude shear and 700 hPa southwest airflow.The analysis of physical field and sounding shows that there is temperature inversion in the lower layer and unstable energy at 700 hPa.The unstable conditions,water vapor conditions and dynamic conditions are all obvious at 700 hPa,which accords with the characteristics of elevated convection.The radar echo is mainly the echo of a layered cumulated mixed cloud system,the echo intensity is less than 50 dBz,and the process is accompanied by lightning activity,which is an elevated weak convective process.