摘要
[Objective] The research aimed to study formation reason of a local heavy rainstorm process in Linyi from night on August 3 to early morning on 4th, 2010. [Method] Based on MICAPS weather chart, actual situation data of NECP analysis field, data of automatic encryption station and Doppler radar product, a local heavy rainstorm and extra heavy rainstorm process in Linyi from night on August 3 to early morning on 4th, 2010 was detailedly analyzed from weather background, meso- and micro-scale characteristics, physical mechanisms of occurrences and developments of meso and micro-scale systems. The formation reason of heavy rainstorm process was discussed. Moreover, we tried to find some occurrence rules of short-time strong precipitation. [Result] The local heavy rainstorm process had large short-time rainfall and obvious local characteristics. The main influence systems were subtropical high, westerly trough, meso- and small-scale ground low pressures. It was affected by many systems which had different scales and heights. The up-cold-down-warm unstable stratification accumulated a large number of unstable energy, which was basic condition of strong precipitation occurrence. It was convergence shear line at the bottom layer of airspace. The vertical shear and turbosphere of deep southwest-northwest-easterly airflow were at airspace. The common effect of up and down systems triggered generation of updraft, and made unstable energy release. For the release of unstable energy, after northwest airflow was cut off, the updraft made southwest airflow develop upward. It linked with easterly wave to form new vertical shear, which was a reason of long duration of strong precipitation. The southwest airflow at the edge of subtropical high was water vapor source of precipitation process, which provided sufficient water vapor supply for generation of heavy rainstorm. The system which was developing and strengthening would make the moving speed of system slow down. Then, the rainfall increased. It was a reason of long duration of strong precipitation. [Conclusion] The research accumulated certain experience for forecast work in future.
[Objective] The research aimed to study formation reason of a local heavy rainstorm process in Linyi from night on August 3 to early morning on 4th, 2010. [Method] Based on MICAPS weather chart, actual situation data of NECP analysis field, data of automatic encryption station and Doppler radar product, a local heavy rainstorm and extra heavy rainstorm process in Linyi from night on August 3 to early morning on 4th, 2010 was detailedly analyzed from weather background, meso- and micro-scale characteristics, physical mechanisms of occurrences and developments of meso and micro-scale systems. The formation reason of heavy rainstorm process was discussed. Moreover, we tried to find some occurrence rules of short-time strong precipitation. [Result] The local heavy rainstorm process had large short-time rainfall and obvious local characteristics. The main influence systems were subtropical high, westerly trough, meso- and small-scale ground low pressures. It was affected by many systems which had different scales and heights. The up-cold-down-warm unstable stratification accumulated a large number of unstable energy, which was basic condition of strong precipitation occurrence. It was convergence shear line at the bottom layer of airspace. The vertical shear and turbosphere of deep southwest-northwest-easterly airflow were at airspace. The common effect of up and down systems triggered generation of updraft, and made unstable energy release. For the release of unstable energy, after northwest airflow was cut off, the updraft made southwest airflow develop upward. It linked with easterly wave to form new vertical shear, which was a reason of long duration of strong precipitation. The southwest airflow at the edge of subtropical high was water vapor source of precipitation process, which provided sufficient water vapor supply for generation of heavy rainstorm. The system which was developing and strengthening would make the moving speed of system slow down. Then, the rainfall increased. It was a reason of long duration of strong precipitation. [Conclusion] The research accumulated certain experience for forecast work in future.
