2013年7月6日安徽省一次大范围暴雨过程分析

［目的］分析2013年7月6日安徽省一次大范围暴雨过程。［方法］运用常规天气资料、NCEP资料，对2013年7月6日安徽省一次大范围暴雨过程的天气形势、物理量场、雷达回波特征等进行分析。［结果］西风带低槽引导冷空气南下和副高西北侧西南暖湿气流在皖江一带交汇造成了这次大范围暴雨过程，西南低空急流的增强为暴雨区提供了充足的水汽和热力条件，暴雨区上空低层辐合、高层辐散重叠，垂直上升运动深厚；暴雨区低层位于正涡度区、θse场的高能区、散度负值辐合中心及水汽通量散度负值水汽辐合中心附近；数值模式WRF V3.4输出产品模拟强降雨时段850 hPa风场，有β中尺度低涡系统先在皖西南地区形成并沿切变线东移；β中尺度低涡系统影响时，回波呈团状，结构紧密，反射率因子一般30～35 dBz，回波顶高6～8 km，团状回波内有多个强度45～50 dBz、顶高12 km的强中心。［结论］该研究为暴雨的预报预测提供理论依据。

Analysis on the Heavy Rainfall in Anhui Province in July 6, 2013

Objective] The research aimed to study the heavy rainfall in Anhui province in July 6, 2013. Method] Using conventional weather data and NCEP data, the weather situation, physical field, radar echo characteristics of the heavy rainfall were analyzed in Anhui prov- ince in July 6, 2013. Result] The intersection of Westerly trough guide cold air southward and southwest warm air of the northwest side of the subtropical high in Little caused the process of heavy rainfall. The enhancement of the southwest low level jet provides for ample moisture and thermal conditions for the storm area. The low-level convergence and upper-level divergence overlap in heavy rain area over, vertical upward motion is deep. The lower rainfall areas located positive vorticity area, high energy area of 0se field, convergence centers of the negative diver- gence and the negative moisture convergence center of water vapor flux divergence. The 850 hPa wind field of heavy rainfall period was expor- ted by numerical model WRF V3.4 ,there is 13 mesoseale vortex system formed firstly in the southwestern region of Anhui and eastward along the shear line. When 13 mesoscale vortex system impact echo the form of pellets, compact structure, the reflectance factor was generally 30 - 35 dBz, echo top was 6 - 8 km ,there were a number of strong center that the strength was 45 - 50 dBz and echo top was 12 km in groups like Echo. Conclusion ] The study provides the theoretical basis for the forecasts and predict of heavy rainfall.