An Analysis of Eastern North Pacific Tropical Cyclone Forecast Errors

Abstract

A statistical analysis is performed of the tropical cyclone forecast advisories and bulletins issued by the Eastern Pacific Hurricane Center, Redwood City, California, during the 1971?78 seasons. Each forecast is normalized by comparison with the performance of an objective model (EPCLPR) that is based on climatology and persistence. The normalized official forecasts show an improvement in skill during the period. This improvement is attributed to the availability of satellite data for determining the storm positions and to the introduction of objective forecast techniques. Forecast errors are related to a number of storm-related variables, such as initial latitude and longitude and deviations from the climatological track. Stepwise discriminant analysis is used to classify the forecasts into groups of above or below average errors.