Forecasting Tropical Cyclone Recurvature. Part I: Evaluation of Existing Methods

Abstract

The ability of three objective tropical cyclone track prediction aids and of the official forecast to indicate that recurvature will occur within 72 h is evaluated. Recurvature is defined as the change of direction from northwest through north to northeast. For the recurvers, the timing of recurvature is assessed within 12-h categories. The evaluation of a homogeneous set of 366 western North Pacific forecasts from 1979 to 1984 provides a standard of comparison for measuring the relative skill of a new objective recurvature prediction technique in Part II of this study. The one-way influence tropical cyclone model is shown to have the highest skill in predicting recurvature for this sample.