摘要
文章利用常规的高低空气象观测资料、T639数值预报产品以及卫星云图产品,对2013年2月16-18日西藏南部区域性暴雪天气过程的环流背景、水汽条件及动力条件进行了诊断分析。结果表明:此次西藏南部区域性暴雪天气是由南支槽前西南风风速辐合,输送暖湿水汽上青藏高原,以及北支槽分裂的短波槽南下共同作用的结果。物理量诊断分析表明,区域性暴雪过程期间,水汽通量、水汽通量散度场、散度场、涡度场和垂直运动场都反映出西藏南部边缘存在大量水汽输送和水汽辐合,上升运动较强,有利于暴雪天气的形成。
The circulationbackground, water vapor condition and dynamic conditions of the regional snow storm weather process in South-Tibet on February 16 - 18 in 2013 were synthetically analyzed by using the routine upper and surface meteorological data, the physical quantity field data of T639 numerical forecast and satellite cloud images. The results showed that theregional snow storm was caused by the front south-west wind speed convergence of Southern Branch Trough 1 short wave trough of North Branch Trou eading to the warm current moving into the Tibetan Plateau and the gh divisionmoving to south. Physical quantities diagnostic analysis showed that there werewater vapor flux, water vapor flux divergence field, divergence field, vorticity field and vertical motion field during the regional snow storm process indicating the existence of a large amount of water va- por transport and convergence at the edge of the Southern Tibetand strong rising movement. These are favorable conditions for the formation of snow storm weather in the region.
关键词
西藏南部地区
区域性暴雪
诊断分析
Southern Tibet
regional snow storm
diagnosis analysis