NAM MOS is a suite of text-bulletin and graphical products developed and supported by MDL. Both product types include meteorological guidance for a suite of variables (Temperature, Dewpoint, Precipitation Amount, etc.). Station-based MOS provides guidance at meteorological station locations (such as airports), while gridded MOS prodvides these products on a grid. Values are based on outputs of the North American Model (NAM) numerical model, and then calibrated using the MOS technique, which was developed by MDL. The MOS equations relating model output to observations have been developed using over 1600 meteorological stations' observations.

Full suites of products are produced for short-range forecasts (6-72 hours in advance) for meteorological stations in the Continental United States, Alaska, Hawaii, Puerto Rico, and the U.S. Virgin Islands. Limited suites of products are produced for marine meteorological stations.