FORECASTING TROPICAL CYCLONE RECURVATURE .1. EVALUATION OF EXISTING METHODS

The ability of three objective tropical cyclone track prediction aids and of the official forecast to indicate that recurvature will occur w ithin 72 h is evaluated. Recurvature is defined as the change of direc tion from northwest through north to northeast. For the recurvers, the timing of recurvature is assessed within 12-h categories. The evaluat ion of a homogeneous set of 366 western North Pacific forecasts from 1 979 to 1984 provides a standard of comparison for measuring the relati ve skill of a new objective recurvature prediction technique in Part I I of this study. The one-way influence tropical cyclone model is shown to have the highest skill in predicting recurvature for this sample.