ECMWF集合预报和确定性预报对淮河流域暴雨预报的对比分析  

Comparison Between ECMWF Ensemble and Deterministic Forecast for Heavy Rainfall in the Huaihe River Basin of China

作　　者：董全 金荣花 代刊 康志明 

机构地区：[1]国家气象中心,北京100081

出　　处：《气象》2016年第9期1146-1153,共8页Meteorological Monthly

基　　金：公益性行业(气象)科研专项(GYHY200906007;GYHY201306002和GYHY201006018);国家科技支撑项目(2009BAC51B03);中国气象局关键技术集成项目共同资助

摘　　要：本文运用2012年5—9月欧洲中期天气预报中心(ECMWF)的集合预报系统(Ensemble Prediction System,EPS)和确定性模式(High-resolution Deterministic forecast,HDet)资料对比分析了淮河流域暴雨的预报效果。对于集合预报,主要对比了基于EPS的日降水量极端天气预报指数(Extreme Forecast Index,EFI),和改进的贝叶斯模型平均(Modified Bayesian Model Averaging,MBMA)法对降水的订正后概率。由于ROC(Relative Operating Characteristic)检验是与模式的系统性偏差无关的,所以选用ROC检验,对比了不同空报率下的TS评分,以及不同方法的相对经济价值。对比检验的结果显示,各时效预报MBMA预报效果最好,其次是HDet,EFI的预报效果最差,其中2 d内的预报HDet接近MBMA,随着预报时效的延长,MBMA相对于HDet和EFI的优势不断增强。在不同标准下确定三种方法对淮河流域暴雨预报的阈值,结果显示MBMA同样优于HDet,EFI预报效果最差。但MBMA的优势是通过增加预报偏差得到,如果将预报偏差限定为主观预报的1.37,此时MBMA的效果和HDet的效果接近。The European Centre for Medium-Range Weather Forecasts （ECMWF） high-resolution deterministic forecasts （HDet） and probability forecasts from the ensemble prediction system （EPS） are evaluated and compared for the heavy rainfall from May to September 2012 in Huaihe River Basin, China. For the EPS, the daily precipitation extreme forecast index （EFI） and the calibrated probability calculated by the modified Bayesian model averaging （MBMA） are used. Relative operating characteristic （R（）C） verifi- cation which is independent of forecast bias is used. The TS vs. false alarm rate （FAR） and the relative economic value are measured. The results indicate that the MBMA has the best performance, followed by the HDet and then the EFI. For the forecast within lead times of 2 days, the HDet is close to MBMA. As the lead times prolong, the advantage of MBMA relative to HDet keeps increasing. Under different criteria, the heavy precipitation forecast thresholds for the three methods are estimated. It is shown that the MBMA is the best and the EFI is the worst. However, the advantage of MBMA is accompanied by higher forecast bias. If the forecast bias is set to be 1.37, which is equal to the subjective forecast of National Meteorological Centre （NMC） forecasters, the MBMA is almost similar to HDet.

关 键 词：集合预报系统(Ensemble Prediction System EPS) 改进型贝叶斯模型平均(Modified Bayesian Model AVERAGING MBMA) 极端预报指数(Extreme Forecast Index EFI) 暴雨 

分 类 号：P456[天文地球—大气科学及气象学]