高空槽引发的黔东南降雹天气过程诊断分析

利用自动站逐时降水资料和FNL1.0°×1.0°资料对高空槽影响下的黔东南地区降雹与非降雹型天气进行合成诊断分析,针对黔东南的特殊地形,计算了垂直螺旋度的局地变化及其分解项,并得出新的诊断量,结合其他动热力因子的分析表明:降雹型天气大气呈上干下湿,非降雹型整层水汽条件差异较小,850hpa水汽辐合强度小于降雹型天气.降雹型螺旋度整层为正值,非降雹型螺旋度在较低层出现较小正值,中上层小于零.降雹型700hpa垂直螺旋度通量散度在降雹前出现闭合的大值区.湿螺旋度在两种类型天气中均为下层负值,高层正值,降雹型湿螺旋度上层与下层之间梯度较非降雹型大.

On Hail Weather Local Vertical Spiral Diagnostic Analysis in Qiandongnan Caused by the Upper Trough Line Diagnosis Analysis

The automatic station hourly precipitation data and FNL1.0°×1.0° data under the influence of the upper trough in the southeast of Guizhou Province hail and non falling hail weather for synthetic diagnosis analysis. In view of the special terrain of Qiandongnan, the local variation of the vertical and its decomposition, and the new diagnostic quantity, and the analysis of the other dynamic factors are obtained:Hail type atmospheric weather is dry wet, non drop hail whole layer of water vapor condition difference is smaller, 850hPa water vapor convergence intensity less than falling hail weather. Hail spiral of the whole layer is positive, non hail type helicity in lower layer appears less positive, less than zero in the upper. The high value of hail type 700hPa vertical helicity flux divergence in the closed before the hail. Moisture helicity in two types of weather are the lower negative and high positive, hail wet type helicity between the upper and lower gradient is non hail type.