The Fire Behavior Research Work Unit (RWU) of the Intermountain Research Station has been developing the Wildland Fire Assessment System (WFAS) since 1994. The WFAS will eventually combine the functionality of the current fire-danger rating system (Deeming et al. 1977) and the fire behavior system (Andrews 1986). The new system will assess fire potential across spatial scales ranging from national to site specific and time scales ranging from near-realtime to 5-day forecasts. The outputs will be useful for fire management tasks ranging from strategic planning to current fire situation analyses (Burgan and Bradshaw 1997). Traditionally, the terms 'fire danger' and 'fire behavior' have described assessments of fire potential on different time and space scales. Fire danger has been evaluated routinely, at least once a day, for broad areas. Fire behavior assessments, however, are made as needed for specific sites. Both use weather that has been forecasted or measured, but fire danger- because of its routine and regular computation requires regularly formatted and routinely available data for automated processing. Fire behavior must have weather inputs matched as closely as possible to the fire site. Fire danger ratings have traditionally been relative values or dimensionless indexes, whereas fire behavior assessments are specific, physical descriptions of expected fire characteristics such as rate of spread, flame length, and fire intensity. As we have been developing WFAS, our goal has been to remove the 'seams' that exist between the current systems (Rothermel and Andrews 1987). For instance, our new 'seamless system' will move easily from evaluating fire danger over a broad area to assessing fire behavior at a specific location. As we develop WFAS, we will continue to resolve incompatibilities such as different sets of fuel models and equation differences. The WFAS framework will address the issue of weak linkages among current systems-fire behavior, fire danger, fire planning, fire effects, and smoke management-and help resolve the confusion that exists on proper application of current fragmented systems. The fire behavior component of the WFAS will be based on the FARSITE Fire Area Simulator (Finney 1995) and will not be discussed here. Instead, we are focusing in this article on broad area fire assessment of the nature typically associated with fire danger rating.