利用加密和常规气象观测资料、静止卫星红外云图和多普勒天气雷达监测产品对2010年8月19—22日辽宁地区一次大暴雨过程的雨情特点、环境条件、水汽输送、能量场、中尺度云团的演变特征、雷达反射率水平和垂直分布特征进行了分析，并探讨了持续性降水过程的发生发展机制。结果表明：辽宁地区此次暴雨过程包括冷涡东移和低涡北上两个降水阶段，总体表现为过程降雨量大、持续时间长、涉及范围广和局地爆发性强的特点。西风带长波槽稳定，副热带高压和日本海高压维持，“东低西阻”形势明显；东北冷涡、高层幅散、低层切变、低空急流及地面气旋等高低空系统耦合。来自北方的干冷空气和南方的暖湿空气在降水区汇合，水汽条件充沛。随着锋面系统东移，暴雨区具有极强的动力抬升条件。中α尺度云团发展，对流云团的组织化特征明显，冷云砧面积决定了强降水范围。多普勒天气雷达强回波长轴方向与回波移动方向一致，“列车效应”引发局地强降水，回波具有后向传播特征，回波垂直结构表明此次暴雨具有低质心的热带降水特点。%Using intensive and conventional meteorological data,geostationary satellite infrared cloud image and Doppler weather radar monitoring products,precipitation features,environment conditions,water vapor transport, energy field,evolution characteristics of mesoscale cloud,horizontal and vertical distribution of radar reflectivity during a heavy rain event on August 19 to 22,2010 in Liaoning province were analyzed. The results indicate that there are two rainfall stages in this period,i. e. cold vortex moving east and low vortex moving north. In general, the heavy rain is characterized with large amount precipitation,long duration,wide range and strong local out-break. Westerly long wave trough is stable. Subtropical high and Japan Sea high are maintained,so the situation of"east low and west resistance" is obvious. The upper and lower systems are coupled,including northeast cold vor-tex,high-level divergence,wind shear in the lower troposphere,low level jet and surface cyclone and so on. The dry cold air from the north and warm humid air from the south converge over the torrential rain region,and vapor conditions for the severe rain is favorable. With the cold frontal moving eastward,lifting conditions grows by the energy front. Many small-scale and mesoscale convective clusters develop into mesoscale convective complex ( MCC). Areas of cold cloud anvil could decide ranges of precipitation. Directions of the echo long axis and echo movement are parallel,thus "train effect" is seen on the radar echo imagery during this precipitation period and leads to local strong precipitation. Meanwhile,radar echo has the characteristics of backward propagation and low centroid which is similar to the tropical heavy rainfall.
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