NWCG Glossary of Wildland Fire, PMS 205

Declination is the difference in degrees between true north and magnetic north.

A fire that has gained headway and built up heat in a structure so as to require greater cooling for extinguishment.

A fire burning far below the surface in duff, mulch, peat, or other combustibles as contrasted with a surface fire.

As it refers to atmospheric pressure, a decrease in the central pressure of a low. This is usually accompanied by intensification of the cyclonic circulation (counter-clockwise wind flow around the low).

A burning with great heat and intense light.

Chemical decomposition by burning material in which the reaction is less than sonic velocity, for example, low explosives.

This is an informal session held immediately following the incident, within 24 hours. It is peer support led, and focuses on initial venting of feelings and stress education.

In a discussion of fire retardant slurries, deterioration of viscosity.

A unit of angular measurement equal to one-360th part of the circumference of a circle. The entire globe contains 360 degrees, each degree contains 60 minutes, and each minute contains 60 seconds.

Polystyrene balls, 1.25 inches in diameter, containing potassium permanganate. The balls are fed into a dispenser, generally mounted in a helicopter, where they are injected with a water-glycol solution and then drop through a chute leading out of the helicopter. The chemicals react thermally and ignite in 25-30 seconds. The space between ignition points on the ground is primarily a function of helicopter speed, gear ratio of the dispenser, and the number of chutes used (up to four). 

A statement provided to the incident commander by the agency administrator delegating authority and assigning responsibility. The delegation of authority can include objectives, priorities, expectations, constraints and other considerations or guidelines as needed.

The resource is no longer assigned to an incident and travel has started, but the resource has not yet arrived home.

The orderly, safe, and efficient return of an incident resource to its original location and status.

Demobilization Unit staff develop an Incident Demobilization Plan that includes specific instructions for all personnel and other resources to be demobilized. They begin their work early in the incident, creating rosters of personnel and resources and obtaining any missing information as check-in proceeds. Once the Incident Commander or Unified Command has approved the Incident Demobilization Plan, Demobilization Unit staff ensure its distribution at the incident and elsewhere, as necessary. For major incidents, demobilization plans are dynamic and the staff in the Demobilization Unit may need to update them frequently.

A layer of clouds whose ratio of dense sky cover to total sky cover is more than one-half.

Sky cover that prevents detection of higher clouds or the sky above it.

The ratio of the original volume of the nonaerated foam solution to the resultant volume of foam. The inverse of expansion.

Above Agency in hierarchy.

Day/Month/Year officially accepted by the Department as meeting all Department requirements to receive funds in the planned year.

An NDVI-derived image of vegetation greenness compared to its average greenness for the current week of the year.

A low place in the ground having no outlet for surface drainage.

The reduction in forest floor thickness due to consumption by fire.

Sometimes referred to as "alligatoring", where combustible material appears to have a fissured or scaly appearance similar to an alligator's hide. Most commonly associated with finished lumber products, such as boards and fence posts.

A fully qualified individual who, in the absence of a superior, can be delegated the authority to manage a functional operation or to perform a specific task. In some cases, a deputy can act as relief for a superior, and, therefore, should be fully qualified in the position. Deputies generally can be assigned to the Incident Commander, EOC director, General Staff, and branch directors.

Chemical that, when applied to a living plant, causes or accelerates drying of its aerial parts; used to facilitate burning of living vegetation by substantially lowering fuel moisture content within a few hours.

Those areas identified as principal population centers or other areas requiring protection under state or federal air quality laws or regulations.

The address where the unit must be physically located, and dispatched from, during the mandatory availability period.

The act or system of discovering and locating fires.

An extreme rapid decomposition of a material in which the reaction is more than a sonic velocity, for example, high explosives.

Temperature to which a specified parcel of air must cool, at constant pressure and water-vapor content, in order for saturation to occur. The dew point is always lower than the wet-bulb temperature, which is always lower than the dry-bulb temperature, except when the air is saturated and all three values are equal. Fog may form when temperature drops to equal the dew point. 

A scale drawing showing information about a fire scene.

Fingers or islands of less intensely burned areas or areas where the fire has self extinguished.

A set of points which defines the terrain as numbers for computer applications. This data may be used to draw contours, make ortho photos, slope maps, and drive fire models.

A control strategy used in managing smoke from prescribed fires in which smoke concentration is reduced by diluting it through a greater volume of air, either by scheduling during good dispersion conditions or burning at a slower rate.

A natural or manmade water site that a helicopter can fill their bucket with water, such as a stream, river, lake, swimming pool, etc...

Any treatment applied directly to burning fuel such as wetting, smothering, or chemically quenching the fire or by physically separating the burning from unburned fuel.

Any treatment applied directly to burning fuel such as wetting, smothering, or chemically quenching the fire or by physically separating the burning from unburned fuel.

That area for which a particular fire protection organization has the primary responsibility for attacking an uncontrolled fire and for directing the suppression action. Such responsibility may develop through law, contract, or personal interest of the firefighting agent (e.g., a lumber operator). Several agencies or entities may have some basic responsibilities (e.g., private owner) without being known as the fire organization having direct protection responsibility. 

The physical characteristics of the indicators that show the direction of fire spread, i.e., advancing, backing, or lateral.

The ICS title for individuals responsible for supervision of a branch. Also, an organizational title for an individual responsible for managing and directing the team in an EOC.

Determination that a fire exists. Location and reporting of a fire is not required as is with detection.

Elapsed time from start of fire (known or estimated) until the time of the first discovery that results directly in fire suppression action.

A separate radio frequency most commonly used in air traffic control which reduces frequency congestion by controlling the number of aircraft or other resources operating on a particular frequency.

The ordered movement of a resource or resources to an assigned operational mission, or an administrative move from one location to another.

An organization from which resources are ordered, mobilized or assigned to an incident and/or demobilized. The center may process requests, coordinate response, or track resources and information under the delegation of its benefiting agency(s).

The dispatch center actively supporting an incident and the resources assigned or a resource who is temporarily transferred for official action i.e. details, temporary duty station, etc.

The dispatch center associated with a resource’s home unit. The Home Dispatch Center is responsible for initial mobilization and is the Center associated with the resource when an assignment is completed.

The current dispatch center for an incident.