How to generate and interpret fire characteristics charts for the U.S. fire danger rating system
The fire characteristics chart is a graphical method of presenting U.S. National Fire Danger Rating System (NFDRS) indexes and components as well as primary surface or crown fire behavior characteristics. Computer software has been developed to produce fire characteristics charts for both fire danger and fire behavior in a format suitable for inclusion in reports and presentations. Scales, colors, labels, and legends can be modified as needed. The fire characteristics chart for fire behavior has been described previously (Andrews et al. 2011). This report describes the fire characteristics chart for fire danger, which displays the relationships among the Spread Component, Energy Release Component, and Burning Index by plotting the three values as a single point. Indices calculated by using FireFamilyPlus can be imported into the fire danger characteristics chart software. Example applications of this software for comparing fire seasons, weather stations, and fire danger rating fuel models are presented.