NWCG Glossary of Wildland Fire, PMS 205

A species with thin bark or highly flammable foliage that has a relatively greater probability of being killed or scarred by a fire.

The organized fire protection service; its members, individually and collectively; allied organizations assisting protection agencies.

Degree to which a site has been altered or disrupted by fire; loosely, a product of fire intensity and residence time.

An aluminized cloth tent that offers protection in a fire entrapment situation by reflecting radiant heat and providing a volume of breathable air.

Removing a fire shelter from its case and unfolding it to use as protection against heat, smoke, and burning embers.

Immediate area where a fire shelter has been deployed.

Type of shovel specifically designed for use in constructing a fireline; has a tapered blade with both edges sharpened for scraping, digging, grubbing, cutting, and throwing.

Training device that imposes simulated fire and smoke on a landscape image, for the purpose of instructing fire suppression personnel in different fire situations and fire suppression techniques.

A code that corresponds to one of several ranges of fire size based on the number of acres within the final fire perimeter.

A not to scale drawing.

A set of physics and empirical equations that form a mathematical representation of the behavior of fire in uniform wildland fuels.

Violent convection caused by a large continuous area of intense fire. Often characterized by destructively violent surface indrafts, near and beyond the perimeter, and sometimes by tornado-like whirls.

Any agent used to extinguish the flaming and glowing phases of combustion by direct application to the burning fuel.

All work and activities connected with control and fire-extinguishing operations, beginning with discovery and continuing until the fire is completely extinguished.

The personnel responsible for fire suppression within a specified area.

The personnel and equipment collectively assigned to the suppression of a specific fire or group of fires.

The management structure, usually shown in the form of an organization chart of the persons and groups having specific responsibilities in fire suppression.

A fire tool that consists of a thick, flat piece of rubber on a long handle used to drag over or smother out flames of grass fires.

A supply of fire tools and equipment assembled in planned quantities or standard units at a strategic point for exclusive use in wildland operations.

An accumulation of highly combustible material, rendering firefighting dangerous.

Any situation in which it is highly dangerous to fight fire.

The use of fire to accomplish a specified objective.

Instructional aid in which the sides of a triangle are used to represent the three factors (oxygen, heat, fuel) necessary for combustion and flame production; removal of any of the three factors causes flame production to cease.

A management distinction, made to satisfy legal and budget constraints, based on whether the ignition source was planned or unplanned. Under the implementation guidance, only two types of wildland fire - wildfire and prescribed fire - are recognized.

The direction of fire spread identified as one of three categories: advancing, lateral, or backing.

Weather conditions which influence fire ignition, behavior, and suppression.

A weather prediction specially prepared for use in wildland fire operations and prescribed fire.

A numerical rating in the Canadian fire danger rating system, based on meteorological measurements of fire intensity in a standard fuel type. (The standard fuel type is representative of jack pine and lodgepole pine.) The FWI is comprised of three fuel moisture codes, covering classes of forest fuel of different drying rates, and two indices that represent rate of spread and the amount of available fuel. 

A meteorological station specially equipped to measure weather elements that have an important effect on fire behavior.

A Fire Weather Watch is issued to advise of conditions which could result in extensive wildland fire occurrence or extreme fire behavior, which are expected to develop in the next 12 to 48 hours, but not more than 72 hours. In cases of dry lightning, a Fire Weather Watch may be issued for the next 12 hours. 

Spinning vortex column of ascending hot air and gases rising from a fire and carrying aloft smoke, debris, and flame. Fire whirls range in size from less than one foot to over 500 feet in diameter. Large fire whirls have the intensity of a small tornado.

Standard 24-hour period beginning at 1000 hours, during which most wildfires undergo a predictable speeding up and slowing down of intensity, depending primarily on the influence of weather and fuel factors.

The greatly increased rate of water run off and soil movement from steep slopes that may follow removal of the vegetative cover by burning.

Removal or treatment of fuels to reduce the danger of fires igniting or spreading. (E.g., fire-proofing roadsides, campsites, structural timber.) Protection is relative, not absolute.

Any source of heat, natural or human made, capable of igniting wildland fuels. Flaming or glowing fuel particles that can be carried naturally by wind, convection currents, or by gravity into unburned fuels.

A natural or constructed barrier used to stop or check fires that may occur, or to provide a control line from which to work.

Set of computerized FIREMODELS run during fire season at the operations coordination center on preselected locations to indicate possible fire spread from those points for that date.

A standardized code used by the federal wildland fire agencies/bureau assigned to effectively track and compile cost information for emergency suppression expenditures. The FireCode is incorporated into each agency’s accounting code structure.

Person whose principal function is fire suppression.

Qualified firefighters, together with their equipment and material, used to suppress wildland fires.

Operational area on which firefighters combat a fire.

Computerized multi-resource model that simulates the effects that naturally caused prescribed fires have on the future production of natural resources such as timber, forage, wildlife, recreation, and water.

For purposes of pay administration for hazardous duty, a fireline is defined as the area within or adjacent to the perimeter of an uncontrolled wildfire of any size in which action is being taken to control fire. Such action includes operations, which directly support control of fire (e.g. activities to extinguish the fire, ground scouting, spot fire patrolling, search and rescue operations, and backfiring).

The part of a containment or control line that is scraped or dug to mineral soil.

Specially developed coils containing explosive powder that are detonated to create a fireline through ground fuels.

The product of the available heat of combustion per unit of ground and the rate of spread of the fire, interpreted as the heat released per unit of time for each unit length of fire edge. The primary unit is Btu per second per foot (Btu/sec/ft) of fire front.

The rate of heat release per unit time per unit length of fire front. Numerically, it is the product of the heat yield, the quantity of fuel consumed in the fire front, and the rate of spread.

Firefighting Resources of California Organized for Potential Emergencies. A multi-agency coordination system designed to improve the capabilities of California's wildland fire protection agencies. Its purpose is to provide more efficient resources allocation and utilization, particularly in multiple or large fire situations during critical burning conditions.