Performance of Parameterization of Sub-scale Physical Processes in Numerical Model and Its Effects on Typhoon Track Forecastings

A new package of parameterization of sub-scale physical processes has been performed for model of typhoon track prediction at Numerical Meteorological Center (NMC), Beijing. Five cases of typhoons, which happened during the summer 1992 (ELI and JANIS), were chosen for the numerical simulations. In comparison of the results obtained by the performed physical processes schemes with those obtained by the old simpler schemes, it is shown that either in typhoon track forecasting or in typhoon intensity prediction, the new schemes are superior to the simpler schemes. In fact, the mean errors of 24 h and 48 h typhoon central forecastings are 188 km and 337 km for the new schemes, respectively, and 226 km and 446 km for the simpler schemes respectively. The mean deviation of 48 h predicted central pressures from the observed ones is 23 hPa for the new scheme, and 26 hPa for the simpler scheme.