the manner in which a fire reacts to fuel, weather, and topography; kinds of fire behavior include the following:

—backing fire a fire spreading, or ignited to spread, into (against) the wind, in the absence of wind, or downslope

—blowup a sudden increase in fire intensity sufficient to preclude immediate control or to upset existing suppression plans, often accompanied by violent convection

—conflagration a raging, destructive fire —note often used to distinguish a raging fire with a moving front from a fire storm

—creeping fire a fire spreading slowly over the ground, generally with a low flame

—crown fire a fire that spreads across the tops of trees or shrubs more or less independently of a surface fire —note crown fires are sometimes classed as running (independent or active) or dependent (passive) to distinguish the degree of independence from the surface fire

—extreme fire behavior a level of fire characteristics that ordinarily preclude methods of direct control, usually involving high rate of spread, prolific crown fires or spotting, presence of fire whirlwinds, or a strong convection column —note extreme fire behavior is difficult to predict because such fires behave erratically, sometimes dangerously

—fire whirlwind a spinning, tornadolike vortex of ascending hot air, flame, smoke, and debris —note a fire whirlwind is one of the most destructive fire phenomena and can have the strength of a tornado

—flareup any sudden acceleration in the rate of spread or intensity of a fire or part of a fire that is of relatively short duration and does not radically change existing control plans

—mass fire a fire resulting from many simultaneous ignitions and generating a high level of energy output

—running fire a rapidly advancing surface fire with a well-defined head and with a marked increase in fireline intensity and rate of spread

—smoldering fire a fire burning without flame and barely spreading

—spot fire a fire ignited beyond the zone of direct ignition from the main fire, caused by windborne sparks or embers

—underburn a fire that consumes surface fuels but not trees and shrubs This definition last updated 08/07/2008