山东省线状中尺度对流系统与多单体风暴的合并特征

利用济南多普勒天气雷达产品和华北区域雷达拼图等资料，普查了2012—2016年影响山东的线状中尺度对流系统(linear mesoscale convective system，LMCS)，分析了LMCS与多单体风暴的合并方式以及合并后的演变趋势等特征，得到如下几条结论：1)LMCS(A)与多单体风暴(B)有A追B，A扩展，A、B相向和B追A四种合并方式；2)LMCS与多单体风暴合并的临界距离为30 km；3)LMCS与多单体风暴合并后，强度增强或维持，尺度增大，生命史延长，长轴将可能转向；4)LMCS与多单体风暴合并时，其本身合并部分将减弱，多单体风暴合并进入LMCS，成为LMCS的一部分；5)合并是雷暴的传播运动造成的；6)63.3%的合并案例会产生雷暴大风、冰雹或强降水灾害，雷暴大风灾害出现的概率最大。

Characteristics of merging between linear mesoscale convective system and multi-cell storm in Shandong

Based on Jinan Doppler weather radar products and radar mosaics of North China, the linear mesoscale convective systems (LMCSs) that affected Shandong from 2012 to 2016 are generally surveyed, and the merging modes of LMCS and multi-cell storm and the evolution trend after merging are analyzed. The results are listed as follows. 1) There are 4 merging modes, A (LMCS) chasing B (multi-cell storm), A extending, A B facing, and B chasing A. 2) The distance threshold of merging between LMCS and multi-cell storm is 30 km. 3) After LMCS merges with multi-cell storm, the intensity increases or keeps, the spatial scale is enlarged, the lifespan is prolonged, and the long axis probably experiences a turn. 4) When LMCS merges with multi-cell storm, the merged part would be weakened, and the multi-cell storm merges into the LMCS, becoming part of the LMCS. 5) The merging results from the propagation of thunderstorms. 6) Thunderstorm gale, hail, or heavy rainfall occurs in 63.3% of the merging cases, and thunderstorm gale has the maximum probability of occurrence.