A major obstacle to the formulation of a systematic methodology within GFE is the disconnect between the sensible weather elements and the atmosphere (Scott and Proton, 2004). In other words, once a set of sensible weather elements is manipulated, it ceases to be physically associated with a 4-dimensional representation (4-D Cube) of the atmosphere. This disassociation renders the systematic use of NWP output in subsequent calculations, using Smart Tools and Procedures, problematic.

The archetype for gridded product generation, the HORACE/OSFM (On Screen Field Modification) system, was developed by the UKMet Office in the late 1990s. Within the technology framework, the UKMet forecaster goes through the forecast process and applies subjective corrections to the atmosphere using the OSFM technique (Carroll, 1997). With OSFM internal consistency is maintained in the dynamic fields through momentum and hydrostatic balance on Potential Vorticity surfaces. Forecasts are derived from the modified representation of the atmosphere. Field modification in the NinJo project (Koppert, 2004) is an ambitious extension to concepts developed by the UKMet Office.

Is it possible, then, to construct a context within the current GFE that would allow a forecaster to maintain a suite of sensible weather element grids that is physically consistent with the 4-D Cube from which it is derived? The answer is not simple as GFE was never designed to perform this task (Scott and Proton, 2004).

This paper lays out a concept of operation, and a limited proof of concept for 4-D grid maintenance within GFE.