2020年6月8日,黔西南出现低涡切变型特大暴雨天气.对常规地面观测资料、高空观测资料、天气雷达资料等分析,结果表明:(1)本次过程主要受高空短波槽、中低层低涡切变、西南低空急流、地面辐合线等系统共同影响;(2)大气不稳定层结明显,贵阳探空来看08时至20时低层湿层较厚,水汽充足有利于暴雨天气产生;河池探空看从08时到20时,整层湿层厚,不稳定能量强,有利于暴雨天气产生;(3)过程中卫星红外云图上暴雨云团稳定发展少动,对流云顶伸展较高,降水主要出现在对流单体冷云区、梯度大值区;(4)回波路径为西北-东南方向,回波在我州呈现旋转形势,一直维持在我州,从而造成南部一线大暴雨以上量级降雨的产生.

Based on the Conventional observation data, satellite data, automatic station precipitation data ,and NCEP/NACR reanalysis data,the rainstorm process during 20:00 9 June to 20:00 10 June in the southwest of Guizhou province was analyzed. The results are as follows:The rainstorm process is mainly caused by the low vortex shear. Low-level convergence improved remarkably around the southwest of Guizhou province trigging the development of the meso-scale convective system when the low vortex shear shift to southeast. The surface rainfall obviously showed meso-scale spatial and temporal distribution feature. low vortex cloud inspired the mesoscale convective system, precipitation emerged mainly in the center in the cluster area or edge of MCS. when and before the storm occurring in the whole southwest of Guizhou province region. There was a strong convergence ascending motion in the lower level, the high-level sank,high divergence, low-level convergence,the wet layer deep, when the air flow to the most powerful formed a cyclone type circulation in the vertical direction, the vorticity is increased obviously, dynamic force upward movement strengthen the lower energy and water vapor upward transportratio. As the shear line shift to the southeastern, water vapor convergence weaken, low level sank, the unstable layer decreases ,and obvious downward extension of neutral layer, the mesoscale convective system weakens and shifted to southeastern.

在以变暖为主要特征的气候变化背景下,黔西南州的温度变化分析。利用了1961~2005年黔西南州8个气象站45年的逐年逐月平均温度、平均最低温度和平均最高温度资料,分析了全州的变暖情况,结果表明,黔西南州年平均温度以0.135℃/10 a的线性趋势增加;四季中春季没有增温趋势变化,冬季、夏季和秋季均有不同程度的增暖,而冬季的增温幅度最大为0.256/10 a。州内不同地区的增温表现明显不同,东南部册亨县和望谟县增温非常明显,增温幅度高于全国平均值,而位于西南部的兴义市的温度变化则呈波动趋势,没有增温趋势。其余地区的增温幅度低于全国平均值。