Extended Abstract

Evaluation of Probabilistic Precipitation Forecast Using TIGGEdata over Huaihe BasinLinna ZHAO 1 Hao WU 1 Fuyou TIAN 1 Dan QI 1 Jingyue DI 1Qingyun DUAN 2 and Zhi WANG 11. National Meteorological Center, China meteorological Center, P. R. China2. College of Global change and Earth System, Beijing Normal University, P. R. Chinazhaoln@cma.gov.cn1.IntroductionRainfall is o ne of the most import ant weather phenomena which could result insevere flood and huge economic loss. A timely and accurate quantitative precipitationforecast (QPF) is a primary goal of operational predictio n and one of the most factorthat af fects the issuance of flood warning( Gourley and V ieux, 2005 ). Short-ran ge,especially medium-range precipitation forecast, have been greatly improved by employingthe ensemble prediction systems (Charba and Klein 1980; Charba et al. 2003). However,quantitative precipit ation forecast s lose skill ra pidly with r ange than forecast of a nyother surface elements (Sanders, 1986), such as the temperature forecast s. In order toimprove a single ensem ble prediction system (EPS), multi-model prediction syst em(MPS) and probabilistic predicti on were developed with considering th echaracteristics of many EPS, i.e.. The simulation of initial uncert ainties (Park et al,2008; Johnson and Swinbank 2009). The THORPEX Interactive Grand Global Ensemble(TIGGE) pro gram pr ovides a ver y g ood op portunity for MPS, probabilistic precipitation,and flood with further research.2. The data and the test catchmentThe European Center for Medium-Ran ge Weather Forecasts (ECMWF), the UnitedStates National Ce nter for Envir onment Predictions (NCEP), and the Chi naMeteorological Administration (CM A) multi- member 1-10 day’ tot al precipit ationforecasting with initial time is 0000G MT obtained from the TIGGE-CMA portal were usedin this study. The Dapoling-Wangjiaba catchment of the upper Huaih e River with 19 raingauges was t aken as th e test case. Three ensemble prediction syste ms (ECMW F,NCEP and CMA) multi-member 1-10 days’ precip itation foreca st from th eTIGGE-CMA archiving center to be used. The test time lasts from 1 July to 6 Augu st,2008. Multi-model combination has more impact than calibration, so no quality controland bias correction are implemented for EPS and MMS. T he equal w eighted factorwas arbitrarily imposed on the MMS with t he assumption that all ensemble membersare equal likely and ensemble size is irrelev ant, not considering the forecasting skillsof individual EPS.3.Methodology and result analysisThe threat score (TS) method, Brier score method and Percentile pr ecipitationmethod were applied to assess thr ee EPSs and their grand EPS. The precipit ationwas divided into four ca tegories with the consistency of op erational forecasts at the-506-