Application of CFSv2 in extended-range forecast of Meiyu characteristics in Hubei province

Abstract

Using daily precipitation model data produced by the second version of Climate Forecasting System of NCEP (CFSv2),the ensemble prediction method is used to carry out regional summer precipitation forecast. Three methods,i.e.,the root mean square error(RMSE) and accuracy(ACCU) of the onset and the ending time of Meiyu,the RMSE of the length of Meiyu,and anomaly sign consistency rate (Pc) of the average rainfall amount of Meiyu,are used to evaluate the forecast ability of the model to the Meiyu characteristics in Hubei province. The results show that the onset of Meiyu forecast is 13 days in advance,the ACCU is above 0.5,and the RMSE is less than 3 days. The ending of Meiyu forecast is 14 days in advance,the ACCU is above 0.5,and the RMSE is less than 3 days. The length of Meiyu period forecast is 14 days in advance,and the RMSE is less than 5 days. The average rainfall amount of Meiyu forecast is 14 days in advance,and the Pc is above 0.5. In general,the aging time of Meiyu characteristics forecast is about 14 days. The CFSv2 model shows certain forecast skill for regional summer precipitation during the Meiyu extended-range period.

Keywords

• cfsv2
• meiyu characteristics
• extended-range forecast
• forecast skill