Evaluation of a kilo-member ensemble for track forecasting

The evaluation of a semi-operational ensemble forecasting system was described with 1980 members for track forecasting. A multigrid barotropic vorticity equation model was used to produce forecast, which reproduces the accuracy of the operational LBAR (a limited area shallow water spectral sine transform) in approximately 1/70 computing time. The ensemble based on 10+1 GFS (global forecasting system) ensemble forecast tracks and consensus ensemble were created to compare the usefulness of the kilo-member ensemble. The average errors of the ensemble mean were compared with those of a single ensemble control member, the GFS ensemble mean, the 5-day Climatology and Persistance (CLPS), the Aviation forecast (AVNO), and other models.