Use of Numerical Guidance at the National Weather Service's National Meteorological Center

Abstract

A brief history is given of the use of Numerical Weather Prediction guidance at NMC since 1958. A review of verification statistics shows that the impact of use of operational prediction models from the Barotropic to the Primitive Equations has been most noticeable in construction of sea-level and 500-mb prognostic charts. Progress in cloud and precipitation forecasting based on NWP guidance has been more modest. Comments are offered on the reasons for this difference in skill. Statistics on the skill of the Limited-Area fine Mesh (LFM) model are provided to indicate its contribution to forecast skill since it began operation in the fall of 1971. A recent case involving the LFM model and the large-mesh P. E. model is used to illustrate current practices in use of NWP for operational forecasting at NMC. Illustrations are given of the application of methods correcting systematic errors in NWP and interpreting the variety of computer products to produce a coordinated prognostic package.