“03.8”辽宁地区暴雨过程成因的诊断分析

Diagnostic Analysis of a Heavy Rain Processin Liaoning Province, 2003

对2 0 0 3年8月5～6日辽宁地区暴雨过程的环流形势及雷达回波进行了分析。并利用中尺度MM5模式对这次暴雨过程的模拟结果进行了诊断分析,探讨了过程中主要影响系统———华北气旋在渤海西岸生成后迅速发展加强的原因。结果表明,中纬度短波槽的充分发展引导贝加尔湖冷空气的南下、副高的稳定与加强和低空急流的建立输送大量暖湿气流是华北气旋生成的重要条件。而“干侵入”则是造成此次华北气旋迅速发展加强的重要原因。

The circulation patterns and radar echo feature of the heavy rain process in Liaoning Province, 5-6 August 2003, are analyzed. The simulation with PSU/NCAR MM5 model and a diagnostic analysis are made to investigate the development causes of the major influence synoptic system (North China cyclone). It shows that the cold air moved southward from Siberia, the stable and strengthened subtropical high and low level warm-moist air flow are the major causes of the event. The dry intrusion plays an important role in the rapid development of the North China cyclone.