NCEP-GFSを用いた複数解析値からの台風進路予報実験

Abstract

Tropical cyclone (TC) track forecast experiments were conducted using the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) with the initial conditions from three numerical weather prediction centers, NCEP, the European Centre for Medium-range Weather Forecasts (ECMWF) and the Japan Meteorological Agency (JMA), to distinguish between TC track forecast errors attributable to the initial state and those attributable to the model. The average position error was reduced by replacing the initial conditions. The northward recurvature of Lupit (2009) was reproduced with initial conditions from NCEP and ECMWF, but not with those from JMA, indicating sensitivity to the initial state. The sensitivity to both the model and the initial state was found, however, for the northward bias of Parma (2009). Insensitivity to the initial vortex structures in the predicted tracks for Parma indicates that the error in the steering flow contributes to the northward bias.