中央氣象局全球預報模式對2016年5～6月東亞區域降雨之預報能力評析

This study examines the capability of the newest generation of Central Weather Bureau Global Forecast System (i.e. CWB/GFS) in forecasting the precipitation over East Asia, during the 2016 May and June. Analyses focus on the performance of predictions at lead times from day-1 to day-10. By comparing the CWB/GFS precipitation forecasts with the NCEP/GFS (National Centers for Environmental Prediction Global Forecast System) precipitation forecasts, our results showed that CWB/GFS has the forecast skill similar with NCEP/GFS in predicting the precipitation over East Asia, during the 2016 May and June. Both CWB/GFS and NCEP/GFS show that (1) the forecast skill at lead times from day-1 to day-5 is better than the forecast skill at lead times from day-6 to day-10, and (2) the forecast skill for the precipitation revealed in June 2016 is better than the forecast skill for the precipitation revealed in May 2016. Analyses also indicate that the differences between the CWB/GFS’s and NCEP/GFS’s forecast skill are closely related to their differences in in forecasting the variation of low-level atmospheric circulation and the moisture flux convergence.