陕西省一次灾害性暴雨天气过程分析

Analysis of a disastrous rainstorm process in Shanxi rovince

利用实况资料和NECP资料、雷达资料对陕西省2010年8月18-25日的暴雨过程进行天气形势分析以及物理量场的诊断,寻找此次暴雨特征,以期对提高今后的暴雨预报有所帮助。结果表明:该次暴雨发生在良好的大尺度环流背景下,伴随着副高先北上后南落,贝加尔湖槽区底部冷空气不断南下,冷暖空气交汇的位置逐渐由北向南移,陕西自北向南经历了一次降水过程。高、低空的有利配置及相互作用,对该次暴雨过程的产生有着很大影响。偏南低空急流和强烈的水汽辐合为暴雨的产生提供了有利的水汽条件;假相当位温高值区和水汽通量散度最大辐合中心与暴雨的落区有很好的一致性。

Based on conventional observation data and NECP data, radar data, the large -scale circulation features and physical quantity field of a heavy rainfall in Shanxi province from 18 to 25, August 2010 were analyzed. In this way, we expected to improve the rainstorm forecasting in the future. The results show that this heavy rainfall occurred in the large -scale circulation, along with the subtropical high it moved northward and then moved southward; the cold air from the bottom of Lake Baikal moved southward constantly, the location of the intersection of cold and warm air moved gradually from north to south, Shaanxi province experienced a precipitation process from north to south. The interaction between high and low altitude had a great impact on the rainstorm. The southern low - level jet and Strong moisture convergence provided favorable moisture for the storm. High potential pseudo - equivalent temperature and the maximum vapor flux divergence convergence center had good consistency with heavy rainfall.