集合动力因子在内蒙古东部暴雨预报过程中的检验分析

Test Analysis of Aggregate Dynamic Factors in the Forecast of Heavy Rain in Eastern Inner Mongolia

针对2017年7月6—7日蒙古东部地区的降水过程,利用NCEP的GFS预报场资料为输入资料,反演得到集合动力因子预报系统中的14个动力因子以及集合平均动力因子,对强降水过程进行诊断分析和预报研究。结果表明,此次降水过程由高低空急流、冷涡、副热带高压和辐合切变线等多个天气系统共同作用造成。湿热力平流参数等多个动力因子预报降水在空间分布上与6 h观测降水基本一致,代表动力因子对降水落区具有较好的指示意义。ETS评分计算表明,动力因子对降水预报有一定的技巧,动力因子的预报效果明显。集合平均动力因子可以反映各种动力因子预报降水的特点,平均集合动力因子与观测降水落区的空间相关系数达到0.63,ETS评分为0.48,明显优于大部分单个动力因子统计结果。

Using the GFS prediction field data of NCEP as input data, 14 dynamic factors and the average aggre- gate dynamic factors were obtained, and the heavy precipitation process in eastern Inner Mongolia from July 6 to 7, 2017 was diagnosed and analyzed. The results showed that the precipitation process was caused by upper and low level jets, cold vortex, subtropical high pressure and convergence shear line. ETS score cal- culation showed that the dynamic factor prediction effect was obvious. The spatial correlation coefficient between the aver- age aggregate dynamic factor and the observed precipitation area was 0.63, and the ETS score was 0.48, which was significantly better than the statistical results of most single dynamic factors.