Forecasting Northeastern Pacific tropical cyclone tracks using an analog scheme.

Abstract

The NEPHAT (Northeastern Pacific Hurricane Analog Tracker) Forecast Program is developed and introduced. NEPHAT selects analog tropical cyclones from 25-year Northeastern Pacific Ocean history. Each selected analog track is statistically adjusted for known differences between it and the recent history of the tropical cyclone being forecasted. The adjusted analog cyclone trajectories are then composited into a single forecast track. Verification results are shown for randomly selected historical cases, with a Monte Carlo simulation of initial operational position inaccuracies. Intercomparisons of forecasts made by NEPHAT and other objective and subjective forecast schemes are presented.