NWCG Glossary of Wildland Fire, PMS 205

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.

The number of subordinates for which a supervisor is responsible, usually expressed as the ratio of supervisors to individuals. The optimum ratio is five-to-one.

Metal wrench used to tighten and free hose connections.

A device installed in a chimney, flue, or exhaust pipe to stop the emission of sparks and burning fragments.

In WIMS, a group of weather stations.

Officially designated special land types within the fire perimeter.

Aircraft operating in accordance with clearances within control zones in weather conditions less than the basic Visual Flight Rules weather minima.

A further categorization of each General Cause to indicate more specifically the agency or circumstance which started a fire or set the stage for its occurrence.

More specific information about the cause or factors contributing to the ignition.

The heat required to raise a unit mass of a substance one degree kelvin. It is the heat capacity of a system per unit mass; i.e., the ratio of the heat absorbed (or released) to the corresponding temperature rise (or fall).

The smaller area within the general origin area where the fire's direction of spread was first influenced by fuel, weather, and/or topography.

Elapsed time from origin of fire to arrival of the first suppression force.

Standby crew in an area of expected high fire occurrence, generally on a day of critical fire weather.

Retardant drop made from one compartment at a time from an airtanker with a multi-compartment tank.

A divergent wind field. Storms moving into a split field tend to lose strength. Winds are generally light in such a flow field.

Combustion of a thermally isolated material initiated by an internal chemical or biological reaction producing enough heat to cause ignition.

A modified form of broadcast slash burning in which the greater accumulations of slash are fired and the fire is confined to these spots.

The second continuous day of an incident, a regular government employee's normal daily tour of duty is "spot changed" to where the first 8, 9, or 10 hours worked are base hours.

Fire ignited outside the perimeter of the main fire by a firebrand.

A method of lighting prescribed fires where ignition points are set individually at a predetermined spacing and with predetermined timing throughout the area to be burned.

A special forecast issued to fit the time, topography, and weather of a specific incident. These forecasts are issued upon request of the user agency and are more detailed, timely, and specific than zone forecasts. Usually, on-site weather observations or a close, representative observation is required for a forecast to be issued. 

In smokejumping, rappelling, and paracargo operations, the individual responsible for selecting drop target and supervising all aspects of dropping smokejumpers, rappellers, or cargo.