A prototype expert system to forecast typhoon conditions at Cubi Point, Philippines

A prototype expert system is designed to forecast the tropical cyclone related winds that may be used to set Conditions of Readiness (COR) at Cubi Point, Philippines. One set of rules modifies the storm position and strength forecasts to account for terrain interactions while crossing the Philippines. A second set estimates the local winds given the modified storm position and intensity. Tests using an independent storm set indicate the terrain-modified positions are comparable in accuracy to current Joint Typhoon Warning Center forecasts. However, the reduction of storm intensity due to terrain is underestimated and the westward translation of the storm is reduced too much. Finally, the conservative strategy of using worst-case wind gust estimates also contributes to an overprediction of the local winds and thus the COR. COR estimates are only 32% accurate, with a 95% capture rate for winds over 35 kt but a 70% false alarm rate due to overforecast of winds under 35 kt. More dynamic/statistical study appears to be required to refine the terrain-modification algorithm. Empirical rules from expert forecaster should be included in future systems.