In the western North Pacific, there has been much improvement over the past five years in track forecasting skill with ever improving numerical models and use of the consensus forecasting approach (see Goerss 2000). At the same time, the average intensity forecasts errors are slightly smaller than errors of purely statistical forecasts based upon climatology and persistence and have varied little during the 1998-2002 period. The relative lack of improvement in intensity forecasting is primarily due to the complexity of the tropical cyclone intensification process, and to a lesser extent to the limited number of quality guidance models specifically designed for this task.

With the complexities involved in tropical cyclone intensity change and the inability for numerical models to be run at the resolutions needed to explicitly resolve convection in a real-time and operational manner, there exist an underlying need for additional intensity forecast methods to gap the shortcomings of existing numerical and purely statistical intensity forecast models. These alternative intensity forecast models would ideally use the strengths of both statistical models and numerical models and would combine the statistical methodology with environmental predictors derived from numerical weather forecasts – or statistical-dynamical approach.

While the statistical-dynamical approach has been successfully exploited in the Atlantic and Pacific east of the dateline (e.g., The Statistical Hurricane Prediction Scheme or SHIPS (DeMaria and Kaplin 1999)) to produce skillful forecasts, until recently such models were unavailable in the Western North Pacific. To address this need, a statistical-dynamical TC intensity model called the Statistical Typhoon Intensity Prediction Scheme (STIPS) was developed and implemented operationally at the Joint Typhoon Warning Center (JTWC) in July 2002 and updated in mid June 2003. Our presentation will discuss the development, and implementation of STIPS as well as its operational performance since June 13, 2003.