The National Meteorological Center's (NMC) Global Data Assimilation and Forecast System is described in some detail. The system consists of 1) preprocessing of the initial guess, 2) optimum interpolation objective analysis, 3) update of the initial guess, 4) initialization, 5) forecast, and 6) postprocessing of the forecast.

The assimilation and forecast system are continually evolving; the version described here was implemented on 30 November 1988.

This content is only available as a PDF.