Statistical Downscale Based on BP- CCA for Daily Precipitation over Sichuan Basin in Summer

Based on one year our cross validation, the BP- CCA is used to build the optimal statistical downscaling between the single predictor and the precipitation over basin of Sichuan province in summer. Then the better predictors are chosen to build a multiple factors statistical downscaling model. It shows that zonal wind at 10 meter height over East Asia, zonal wind at 700hPa height over East Asia and relative humidity at 700hPa height over East Asia are better predictors to forecast the precipitation over basin of Sichuan, but the multiple factors statistical downscaling model shows higher forecast skill. It is higher skill of applying the multiple factors BP- CCA downscaling to the results of T639 than that in case only the T639 model is used.