Prediction of typhoon wind by Level 2.5 closure model

This paper proposes a model predicting the wind speed and direction of typhoon wind. The modelʹs performance corresponds to that of the Level 2.5 mesoscale model by Mellor and Yamada. Typhoon pressure is based on the Schloemer model and typhoon parameters are evaluated from data of the Japan Meteorological Agency. The coordinate system is cylindrical terrain-following coordinate considering whirling wind and irregular topography. The proposed model is applied to two strong typhoons, T9119 and T0314. The former is observed at 100 m elevation at the foot of mountains and the latter is observed at 14.5 m elevation on flat terrain. Simulated wind speeds and directions agreed well with the observed ones. Vertical profiles of wind and radial profiles of temperature are also examined. The computational time spent on a 1-day simulation is about 3 h (computer: COMPAQ Alphaserver ES45).