Boolean logic for predicting fire types.

Predicted fire types based on the wind speed at which the Transition Ratio and Active Ratio are 1(YES). If the Transition Ratio is ≥1 for a given wind speed, Surface Fireline Intensity is sufficient for transition to crown fire at that wind speed or greater. If the active ratio is ≥1 for a given wind speed, the fire is predicted to be an active crown fire at that wind speed or greater. Fire types are: 1) Surface (understory fire that does not reach the crowns), 2) Torching (also known as Passive Crown Fire; surface fire with occasional torching of individual trees), 3) Conditional Crown (active crown fire possible, if the fire transitions to the overstory, but such crown transition is not predicted in the current stand for the given wind conditions), and 4) Active Crown Fire (fire spreads from crown to crown).