Fast Generation of Ensemble Typhoon Wind Field and Its Application

This paper presents an efficient method to fast generate the ensemble typhoon wind field by using the forecast wind data obtained from several operational weather forecast centers. The weighted bias-removed ensemble mean (WEM) method is utilized to generate the characteristic parameters, i.e., typhoon track and maximum wind speed, for the control typhoon. Based on the error analysis of typhoon forecasts during the training period, 15 ensemble typhoon members are then generated by combination of 5 different typhoon tracks and 3 different maximum wind speeds from those of the control typhoon. Finally 15 ensemble wind fields are generated by applying the Jelesnianski typhoon model on each ensemble member. The generated ensemble wind fields are used in the forecast of storm surge for Typhoon Haikui (1211) and the results show that the ensemble forecast method can effectively increase the reliability and accuracy of the storm surge forecast.