不同类型暴雨过程的ECMWF模式降水偏差及订正方法  

Precipitation forecast deviation and correction of ECMWF mode for different types of rainstorms

作　　者：彭艳青[1] 鞠亮亮 张昆[1] PENG Yanqing;JU Liangliang;ZHANG Kun(Huaihua Meteorological Bureau,Huaihua 418000,China)

机构地区：[1]湖南省怀化市气象局,湖南怀化418000

出　　处：《贵州科学》2022年第3期58-61,共4页Guizhou Science

基　　金：湖南省气象局短平快项目(XQKJ21B017)。

摘　　要：为提高暴雨预报准确率,减少暴雨灾害损失,利用常规及非常规观测资料、ECMWF模式预报资料及NCEP逐6 h再分析资料,对2021年5月15日及2021年7月1日发生在怀化的两次不同类型暴雨天气过程的ECMWF模式降水偏差及订正方法进行分析研究,给出了预报这两类暴雨着眼点和订正预报的思路。结果表明:5月15日过程是一次暖平流强迫类降水过程,对流性降水特征明显,暴雨区与地面辐合线配合较好,ECMWF模式对影响系统预报略偏北、对对流性降水预报偏弱、对地形引起的降水增幅的预报能力有限,使得降水预报偏差较大,在对流性降水预报的基础上进行相应订正将取得较好的预报效果;而7月1日过程是一次系统性的低涡切变类暴雨天气过程,强降水出现在850 hPa切变线南侧,暴雨主要处于850 hPa急流轴出口左侧,ECMWF模式对影响系统预报偏北、维持时间预报偏短、切变强度预报偏弱、对对流性降水预报偏大,使得降水预报偏差较大,在大尺度降水预报的基础上进行相应订正将取得较好的预报效果。In order to improve the accuracy of rainstorm forecast and to reduce the loss caused by rainstorm disasters, the precipitation forecast deviation and correction of ECMWF mode for two different types of rainstorms occurred on 15 May, 2021 and 1 July, 2021 in Huaihua were analyzed based on conventional and non-conventional observation data, ECMWF mode forecast data and NCEP reanalysis data.The approaches to forecasting the two types of rainstorms and to revising the forecast were given.The results showed that: the rainstorm on 15 May, 2021 was a forced warm advection-like precipitation process with obvious convective characteristics, and the rainstorm area was well matched with the surface convergence line;the reasons for the large forecast deviation were that the predicted position of the influence system was off to the north, the predicted convective precipitation was weak, and the ability of ECMWF mode to predict the precipitation increase caused by topography was limited;corresponding correction should be made on the basis of the convective precipitation forecast.The rainstorm on 1 July, 2021 was a systematic low vortex shear-like rainstorm, the heavy rainfall occurred to the south of the 850 hPa shear line, and the rainstorm was mainly located on the left side of the exit of the 850 hPa jet stream axis;the reasons for the large forecast deviation were that the predicted position of the influence system was off to the north, the predicted maintenance time was short, the predicted shear intensity was weak, and the predicted convective precipitation was heavy;corresponding correction should be made on the basis of the large-scale precipitation forecast.

关 键 词：暴雨 ECMWF模式 降水偏差 订正 

分 类 号：P456[天文地球—大气科学及气象学]