赣东一次冬季暴雨过程诊断分析

Diagnostic Analysis of a Winter Rainstorm in Eastern of Jiangxi Province

利用自动站观测资料和常规观测资料对2016年11月25-26日赣东冬季暴雨的天气成因及中尺度特征进行分析,结果表明:本次暴雨过程是高空槽移动缓慢,长时间滞留导致槽前暖湿气流与冷空气作用形成的持续性降水过程。同时其与中低层切变线南压,高空辐散与低层辐合抽吸作用,急流输送水汽,较长的持续时间都有密切联系。另外,相比汛期暴雨的经验指标,此次冬季暴雨过程中水汽通量值和水汽通量散度明显偏小,但相对冬季来说水汽强度较大;假相当位温、K指数等明显偏小,大气层结比汛期暴雨要稳定得多,未出现明显的对流性天气。

Based on automatic station observation data and conventional observation data, the causes and mesoscale characteristics of the winter rainstorm were analyzed in eastren of Jiangxi Province from November 25 to 26,2016. The results showed that the rainstorm process was that the high-altitude trough moved slowly, and the long-time detention lead to the continuous precipitation process caused by the warm air current and the cold air. However, it was closely related to the southward pressure of the middle and low level shear line, the divergence of the upper level and the convergence suction of the lower layer, the vapor transport of the jet stream, and the longer duration. In addition, the water vapor flux and water vapor flux divergence were obviously smaller during the winter rainstormr, but the water vapor intensity was relatively stronger in the winter. False equivalent temperature, K index was significantly smaller, the atmospheric stratification than the flood season to be much more stable, which was no significant convective weather.