Estimation and removal of forecast cycle stray

We have found spatial and temporal coherencies in the departures of shortrange- forecasts from observed and analyzed geopotential fields, which can be used diagnostically and as the basis for adjustment of forecast products. We identify characteristics of the differences between forecast and observed, and forecast and analyzed values; and we demonstrate the significant impact on forecast accuracy which may be gained through the routine estimation and removal of these discrepancies. In addition, we devised and tested a mechanism for estimating and removing these discrepancies, globally, in the data assimilation step of the forecast cycle. 1988 NWS (National Weather Service) NCEP (National Centers for Environmental Prediction) Library Public Domain 2285