The Limited-Area Forecast Systems at the Central Weather Bureau in Taiwan

Abstract The Central Weather Bureau (CWB) in Taipei, Republic of China has entered the era of operational numerical weather prediction with the complete online operations of a Global Forecast System (GFS) and the Limited-Area Forecast Systems (LAFS). A brief description of the Regional Forecast System (RFS) and the Mesoscale Forecast System (MFS) of the LAFS are presented in this paper. The RFS has a horizontal resolution of 90 km, depends on the GFS for boundary values, and produces forecast up to 48 h over the eastern parts of Asia and the northwestern Pacific Ocean. The MFS has a resolution of 45 km, uses RFS analysis and forecast as initial and boundary conditions, and produces 24-h forecasts for Taiwan and its immediate vicinity. Model configurations, numerics, physical parameterizations, performance statistics, and two significant weather cases of the two forecast systems are discussed. Future improvements and new plans will also be given.