The HPC model diagnostic meteorologist prepares the Model Diagnostic Discussion which evaluates the NAM and GFS along with other operational model and ensemble guidance for each significant system affecting the continental U.S. through 84 hours from model initialization.

This discussion emphasizes model differences and preferences, with an evaluation of NAM/GFS analyses if there are significant errors and a review of model trends and biases if appropriate.  There are four issuances during each of the day and night shifts corresponding to the arrival of latest model data.

The following table shows the deadline and content for each issuance.


0315Z/1515Z		Evaluate NAM initialization
			Compare the NAM to latest runs of other models/ensembles

0445Z/1645Z		Evaluate GFS initialization
			Compare GFS to NAM and other guidance
			Review NAM/GFS trends and biases as appropriate
			Discuss model preferences

0530Z/1730Z		Compare UKMET/Canadian global models to current guidance
			Update model preferences as needed

0645Z/1845Z		Evaluate latest ECMWF run
			Finalize model preferences

During the cool season (Nov 1 - Apr 15), this meteorologist is also primarily responsible for requesting reconnaissance flights whenever the potential exists for major winter storm development over the East or Gulf Coast states.  (Remove reference to tropical coordination.)