台风“麦德姆”影响山东的暴雨特征分析

Characteristics of rainstorm caused by typhoon "Matmo" in Shandong Province

利用常规观测资料、地面加密自动站资料、NCEP/NCAR再分析资料和风廓线雷达等资料对2014年第10号台风"麦德姆"影响山东的暴雨特征进行了分析。结果表明:强降水出现在台风路径的左侧及台风中心附近。前期为台风环流本身造成的降水,后期为中低纬系统相互作用造成的强降水。台风暴雨落区与整层大的比湿、强烈的水汽通量辐合和中层存在强上升运动速度大值区有关。冷暖空气相互作用在台风中心北侧低层产生温度梯度大值区抬升了高层暖湿空气导致暴雨的产生。正负垂直螺旋度加强的时段刚好和鲁中东部、鲁东南和山东半岛的强降水集中时段相对应。此次风廓线雷达对此次台风的短时强降水有较好的指示意义,低层东北风的向上扩展和风力的加大对应着降水强度的逐渐增强。

By using conventional meteorological observation data,dense AWS data,NCEP/NCAR data and wind profile radar data,the characteristics of rainstorm caused by typhoon'Matmo'in Shandong Province are analyzed. The results show that the rainstorm area appears on the left side of the typhoon path and typhoon center.It is typhoon circulation precipitation for the first period and the heavy rainfall of the later period was caused by the interaction between mid-and low-latitude systems. Typhoon rainstorm distribution relates to the higher specific humidity,strong moisture flux convergence and the maximum velocity area of powerful updraft at the middle level. The interaction between warm and cool air on the north side of typhoon center at the low level produces high temperature gradient forcing the warm wet air in the high level and causes rainstorm. There is a good correspondence between the evolution time of vertical helicity and the strong rainfall period in the Mid-east,Southeast and Peninsula of Shandong. It is indicative for the wind profile radar on the typhoon short-time strong precipitation,the scale-up and velocity enhancement increase of the northeast wind in lower layer correspond to the increasement of precipitation intensity.