NWCG Glossary of Wildland Fire, PMS 205

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.

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.

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.

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.

Phase of combustion immediately following flaming combustion. Emissions are at twice that of the flaming combustion phase.

A standing dead tree or part of a dead tree from which at least the leaves and smaller branches have fallen. Often known as a stub, if less than 20 feet tall.

A fixed tank attached to the belly of the helicopter that has a pump-driven snorkel attached. The helicopter hovers over the water source with the end of the snorkel immersed, the pump then fills the tank.

Commonly accepted term for short length of large diameter soft hose used to connect a structural or wildland engine with a hydrant. No vacuum is involved because the hose is useful only when the engine receives water at a rate of flow in excess of the demand of the pump. 

The amount of sunlight exposed to the fuels.

Carbon dust formed by incomplete combustion.

Objects displaying more soot deposits on the exposed surface of the object than on the protected surface of the object indicating the direction of fire progression at that location. One of the 11 NWCG categories of fire pattern indicators.

Single round trip made by an airtanker from a tanker base to a fire and return.

A signaling device mounted on retardant aircraft which generates a tremulous siren sound to warn firefighters on the ground that a plane is approaching to drop retardant.

A sampling of upper air conditions made by means of instruments and a small radio transmitter on a free balloon. Automatic radio signals originated by action of weather instruments are sent to a ground receiver. These signals are interpreted for use in analyzing and predicting upper air conditions over a wide area of the earth. Weather elements determined at a number of altitude points as the balloon rises are temperature, atmospheric moisture, pressure, wind direction and speed. Similar soundings may be made using fixed balloons or tethersondes.

A point, line, or area, at which mass or energy is added to a system, either instantaneously or continuously. Examples of sources in the context of air pollution are as follows: a smoke stack is a point source; a freeway is a line source; field or slash burning are area sources.

Chipping or pitting of concrete, masonry, or stone surfaces.

Distance equal to the wingspread of the airtanker being used; used for corrections right or left of the flight path.