【摘要】 2007年5月和2006年6月两次相似的强对流天气给浙江省带来了强烈的雷雨大风和短时冰雹天气,这两次过程最主要的特征表现在中高层蕴含深厚的冷空气条件,而低层存在浅薄的暖湿气流。综合运用雷达卫星及NCEP实况资料,对比分析了强对流发生发展的环境条件、云图及回波特征,进而揭示出此类天气的主要特点和可预报性。分析发现,925hPa的切变线形成中尺度触发机制,对预报雷暴的发展走向具有不可忽视的作用;冷空气南下造成的冷暖平流交汇是触发对流的主要原因;云图上,云系移动前方形成较大的亮温梯度,后方形成干涌边界;雷达回波中表现出阵风锋的影响,这些都是地面灾害性大风产生的主要征兆。另外,强回波对应较大的风向切变区和悬挂回波是冰雹产生的重要特征。更多还原

【Abstract】 Two similar severe convection weather brought severe gale and thunder storm with short-lived hail to Zhejiang province in May, 2007 and June, 2006. The common characters of the two weather processes showed that thick cold air existed above middle- level and the low-level had thin warm and wet airflow. Synthetically utilizing Doppler radar, nephogram, actual data and NCEP reanalysis data to analyse contrastively environment condition, nephogram and echo character of the convection weathers. Further to open out the main characters and predictability about the kind of weather. The primary results had been found as follows: the 925 hPa shear was very important for forecasting such thunder storm, which formed trigger mechanism. The convergence of cold and warm air advection was main reason to trigger off convection. On the TBB cloud image, TBB grads appeared on the front of convective cloud, dry boundary was showed on the back of convective cloud. The radar detected gust front. These were the primary symptoms ofdevastating gale. In addition, wind direction shear and echo hang were the main symptoms of hail.更多还原