摘要
2006年5月26日和6月25日三门峡辖区均出现了以地面大风、冰雹为主的灾害性天气。利用常规观测资料和非常规加密探测资料以及雷达、卫星云图资料对这两次灾害性天气过程进行诊断分析，结果表明：这两次灾害性天气均是由500hPa华北冷涡后部的下滑槽或横槽转竖带动北方冷空气急剧南下造成的下击暴流引发的强对流天气。当雷达回波顶高超过10km、强度≥50dBz并出现回波悬垂结构的超级对流单体或多单体超级对流风暴移来时，易产生强对流天气；强回波质心在移动过程中不断下降或回波悬垂结构、低层弱回波区出现在风暴后部时．是下击暴流发生的前兆；冰雹指数、风暴跟踪信息、中气旋3个产品叠加对强对流风暴发生、发展、移向的预报具有较好的参考作用。
There were two severe weather processes which are characterized by surface wind and hail happened on 26 May and 25 June 2006 in Sanmenxia. The diagnostic analysis of these two weather processes is made by use of conventional observational data, non-conventional encryption probing data, radar and satellite picture data. The result shows that these two severe weather processes were all initiated by downbursts which were caused by the rapidly moving southward cold air, the cold air was driven by the downslide trough or vertical cross-slot switch of the cold vortex in north China at 500 hPa circulation. When the super convective cell or muhi-unit super convective storm moves closely with the characteristic of overhanging structure, the radar echo top is over 10 km and the echo intensity is greater than or equal 50 dBz, it easily lead to the occurrence of severe convective weather; if the centroid of strong echo continually decreased during it＇ s moving process or the echo overhanging structure, low-level weak echo region appeared at the back of the storm, this is the precursor of downburst; the superposition of hail index, storm tracking information and mesocyclone has a reference role for the prediction of arise, development and moving direction of severe convective storm.
出处
《气象与环境科学》
2010年第B09期115-120,共6页
Meteorological and Environmental Sciences
