NWCG Glossary of Wildland Fire (PMS 205)

An offender who intentionally sets one fire.

Technique whereby fire retardant is released from only one compartment of an airtanker.

An individual, a piece of equipment and its personnel complement, or a crew/team of individuals with an identified work supervisor that can be used on an incident.

Equipment is staffed with 1 operator or crew. A normal shift could be up to 16 hours long and may cross calendar days.

Centrifugal pump with a single impeller.

Removal or killing of unwanted vegetation, residue, etc. by use of fire, herbicides, or mechanical treatment in preparation for reforestation and future management.

Fire ignited to expose adequate mineral soil and control competing vegetation until seedlings of the desired species become established.

Analysis of factors which influence suppression of an escaped fire from which a plan of attack will be developed; includes development of alternative strategies of fire suppression and net effect of each.

An on-going process of gathering information by observation and by communication with others. This information is integrated to create an individual's perception of a given situation.

Situation Unit staff collect, process, and organize situation information, prepare situation summaries, produce maps, and develop projections and forecasts related to the incident. They gather and disseminate information for incident and agency decision processe.

An on-going process of gathering information by observation and by communication with others. This information is integrated to create an individual's perception of a given situation.

A daily safety briefing for wildland fire that focuses on high risk events found within a firefighter's scope of work that are performed on an infrequent basis.

Identifies the fire size based on number of acres within the final fire perimeter

As to size of wildfire:

Class A - one-fourth acre or less;
Class B - more than one-fourth acre, but less than 10 acres;
Class C - 10 acres or more, but less than 100 acres;
Class D - 100 acres or more, but less than 300 acres;
Class E - 300 acres or more, but less than 1,000 acres;
Class F - 1,000 acres or more, but less than 5,000 acres;
Class G - 5,000 acres or more.

The evaluation of the fire to determine a course of action for suppression.

Load of hose specially arranged on top of a standard hose load to permit dropping the working line at the fire.

Any road or trail formed by the process of skidding logs from stump to landing.

A self-contained unit consisting of a water tank, fire pump, and hose specially designed to be carried on a logging skidder for use in forest fire suppression.

Any aircraft equipped to pick up water while moving on or over water.

Amount of clouds and/or other obscuring phenomena that are detectable from the point of observation.

Debris resulting from such natural events as wind, fire, or snow breakage; or such human activities as road construction, logging, pruning, thinning, or brush cutting. It includes logs, chunks, bark, branches, stumps, and broken understory trees or brush.

Treatment of slash to reduce fire hazard or for other purposes. Preferred to "brush disposal."

A net attached by a lanyard to a helicopter cargo hook and used to haul supplies.

Any cargo carried beneath a helicopter and attached by a lead line and swivel.

A hand operated instrument for obtaining wet and dry bulb temperature readings and, subsequently, relative humidity.

A tank, a live hose reel or tray, an auxiliary pump, and an engine combined into a single one-piece assembly which can be slipped onto a truck bed or trailer.

A self-contained unit including an auxiliary engine driven pump, piping, a tank, and hose storage that is designed to be placed on a truck chassis, utility bed, flat bed, or trailer. Such units can typically be attached and removed from the vehicle with a minimum amount of time and effort.

The rise or fall in terrain measured in feet per 100 feet of horizontal distance measurement, expressed as a percentage.

One of five categories used to describe the topography of a fire danger rating area.

The ratio between the amount of vertical rise of a slope and horizontal distance as expressed in a percent. One hundred feet of rise to 100 feet of horizontal distance equals 100 percent.

The ratio between the amount of vertical rise and horizontal distance of the terrain as expressed in a percent that represents the typical slope in the immediate vicinity of the point of origin of a fire. Point of origin is the location where a competent ignition source came into contact with the material first ignited and sustained combustion occurred.

Small scale convective winds that occur due to local heating and cooling of a natural incline of the ground.

A fire edge that crosses a control line or natural barrier intended to confine the fire.

The discharge of distinct pockets of water and air due to the insufficient mixing of foam concentrate, water, and air in a compressed air foam system.

An aircraft of 12,500 pounds (5,669 kg) or less, maximum certificated takeoff weight.

Generally considered only photochemical air pollution. Originally meant a combination of smoke and fog.

Small particles of carbon, tarry and water vapor resulting from the incomplete combustion of carbonaceous materials such as wood, coal or oil.

The amount of combustion products found in a specified volume of air, commonly expressed as micrograms of emission per cubic meter of air.

Smoke from prescribed fire entering a designated area at unacceptable levels.

The policies and practices implemented by air and natural resource managers directed at minimizing the amount of smoke entering populated areas or impacting sensitive sites, avoiding significant deterioration of air quality and violations of National Ambient Air Quality Standards, and mitigating human-caused visibility impacts in Class I areas. 

Extensive, thick blanket of smoke spreading more or less horizontally from a fire.

The gases, smoke, and debris that rise slowly from a fire while being carried along the ground because the buoyant forces are exceeded by those of the ambient surface wind.

Area in which smoke from outside sources is intolerable, for reasons such as heavy population, existing air pollution, or intensive recreation or tourist use.

An area that may be adversely affected by smoke from a prescribed burn.

Level, in the vicinity of the fire, at which the smoke ceases to rise and moves horizontally with the wind at that level.

A dense fog (water droplets suspended in the atmosphere) that forms away from a fire site when surface smoke comprised of increased fine particulates and water vapor, combines with ambient air that is already prone to natural fog formation.

The symbol of the Cooperative Forest Fire Prevention Program since 1945. Smokey's image is protected by US Federal Law and is administered by the USDA Forest Service, the National Association of State Foresters and the Ad Council.

Discarded or improperly managed cigarette butts or other smoking paraphanalia that leads to a wildfire ignition.

Wildfires caused by smokers from matches, lighters, tobacco, or other smoking material.

Combined processes of dehydration, pyrolysis, solid oxidation, and scattered flaming combustion and glowing combustion, which occur after the flaming combustion phase of a fire; often characterized by large amounts of smoke consisting mainly of tars.