2014年张家界市一次局部强降水过程总结分析

Analysis on a local heavy rainfall process of Zhangjiajie in 2014

应用常规观测资料和数值预报产品资料对2014-06-26张家界市西北部桑植县境内出现的强降水天气过程进行全面的分析、各家数值预报检验和预报经验总结。结果表明:造成此次局地强降水天气的主要影响系统是500hPa低槽、700hPa切变、850hPa低涡切变、西南急流以及地面冷锋;暴雨过程具有明显的中尺度MaCS特征,强降雨与TBB梯度的大值区对应;暴雨的发生具有充足的水汽条件,比湿达14kg/kg,水汽通量散度辐合区位置、时间对强降水发生的位置、时间有较强指示意义;强降水区具有较强的上升运动和不稳定能量,为强降水的发生提供了动力条件;数值预报参考价值大。

Using conventional observations and numerical weather forecast product information, the heavy rainfall process in Sangzhi located in the northwest city of Zhangjiajie on June 26, 2014 is comprehensively analyzed. The different numerical predictions are checked and the forecasting experience is summarized. The results show that this local heavy rainfall is mainly caused by 500 hPa low trough,700 hPa shear,850 hPa vortex shear,southwest jet and surface cold front. This rainstorm processes obvious features of mesoscale MaCS and the heavy rainfall region corresponds to the big value gradient of TBB. The rainstorm occurred with sufficient moisture conditions and specific humidity over 14kg/kg. It has good indication significance of time and location of vapor flux divergence convergence on the occurrence of heavy rainfall. Strong precipitation area has a strong upward motion and higher unstable energy, which gives a dynamic condition to heavy rainfall and provides great references for numerical prediction.