“6·18”江汉平原特大暴雨中尺度特征

利用NCEP GFS再分析资料（分辨率0．5°×0．5°）以及地面、新一代天气雷达等观测资料，针对2011年6月18日江汉平原特大暴雨过程进行中尺度特征分析。结果表明，江汉平原附近深厚的中尺度低涡是造成此次强降水的主要天气系统，对流层中层和边界层的干线以及地面中尺度低压是其主要触发机制，强大的西南急流发展为暴雨区提供了充足的水汽。雷达回波特征分析表明，0℃层以下大于45dBz回波垂直伸展厚度、垂直液态含水量大小与10min降水量有非常好的一致性。

Mesoscale characteristics of the torrential rain over the Jianghan Plain in Hubei Province on 18 June

The NCEP GFS reanalysis data （resolution of 0.5° x 0. 5°） and surface observation and Doppler radar data were used to analyze the mesoscale systems of the torrential rain which occurred o ver the Jianghan Plain in Hubei on 18 June. Results show that the torrential rain was mainly caused by the deep low vortex over the Jianghan Plain, the dry line in the middle troposphereboundary layer and mesoscale low pressure on surface were the main trigger mechanism, and the southwest jet offered suffi cient vapor for the rain. After studying the radar echoes feature, it is found that the rain intensity was in good consistency with the vertical thickness of radar reflectivity factor above 45 dBz under 0℃ level and with the vertical integrated liquid value.