Major Numerical Forecast Failures over the Northeast Pacific

Strong North Pacific storms that impact the North American west coast are sometimes poorly predicted in the short term (up to 48 h) by operational models, with cyclone position errors of hundreds of kilometers and central pressure errors of tens of millibars. These major numerical forecast failures still occur despite continuing improvements in modeling and data assimilation. In this paper, the frequency and intensity of sea level pressure errors at buoy and coastal locations are documented by comparing the National Centers for Environmental Prediction (NCEP) Eta Model forecasts to observations and through case studies of two poorly forecast cyclones from the 2001/02 winter season.