NWCG Glossary of Wildland Fire, PMS 205

Time, in hours and fraction of hours, that a precipitation event lasts. More precisely, for fire danger rating purposes, the length of time that fuels are subjected to liquid water.

Device commonly used to collect and permit measurement of any form of rain and snow sufficiently heavy to have fallen to the earth's surface.

A standard instrument approach procedure for fixed-wing aircraft in which an electronic glide slope is provided, such as ILS and PAR.

Blind landing in which the aircraft is observed from the ground by means of radar and directed along a suitable glide path by instructions radioed to the pilot.

Hard suction hose or discharge hose carried connected to pump, eliminating delay occasioned when hose and nozzles must be connected and attached at fire.

Those Geographic Area and National-level fire weather or fire danger services and products produced by wildland fire agency meteorologists and intelligence staffs in support of resource allocation and prioritization.

Thermal or chemical decomposition of fuel at an elevated temperature. This is the pre-combustion stage of burning during which distillation and pyrolysis predominate. Heat energy is absorbed by the fuel which, in turn, gives off water vapor and flammable tars, pitches, and gases. These ignite when mixed with oxygen to initiate the flaming combustion phase. 

Preliminary phase of combustion in which fuel elements ahead of the fire are heated, causing fuels to dry. Heat induces decomposition of some components of the wood, causing release of combustible organic gases and vapors.

Activities that lead to a safe, efficient, and cost-effective fire management program in support of land and resource management objectives through appropriate planning and coordination.

The range of deliberate, critical tasks, and activities necessary to build, sustain, and improve the capability to protect against, respond to, and recover from domestic incidents.

Mental readiness to recognize changes in fire danger and act promptly when action is appropriate.

Increments of planning and organizational readiness dictated by burning conditions, fire activity, and resource availability.

A written plan providing for timely recognition of approaching critical fire situations, priority setting, the deployment of forces, and other actions to respond to those situations.

Application of prescribed fire.

A wildland fire originating from a planned ignition in accordance with applicable laws, policies, and regulations to meet specific objectives.​

A plan required for each fire application ignited by management. Plans are documents prepared by qualified personnel, approved by the agency administrator, and include criteria for the conditions under which the fire will be conducted (a prescription). Plan content varies among the agencies.

Indicates whether the wildfire resulted from an escaped prescribed fire. Y or N.

A team of skilled and mobile personnel dedicated primarily to prescribed fire management that can ignite, hold and monitor prescribed fires.

A plan required for each fire application ignited by management. Plans are documents prepared by qualified personnel, approved by the agency administrator, and include criteria for the conditions under which the fire will be conducted (a prescription).

In the context of wildland fire, a prescription is measurable criteria that define conditions under which a prescribed fire may be ignited. Prescriptions may also be used to guide selection of management responses to wildfire to define conditions under which management actions are most likely to achieve incident management objectives. Prescription criteria typically describe environmental conditions such as temperature, humidity and fuel moisture, but may also include safety, economic, public health, geographic, administrative, social, or legal considerations. 

The difference in atmospheric pressure between two points on a weather map. That is, the magnitude of pressure difference between two points at sea level, or at constant elevation above sea level. Wind speed is directly related to pressure gradient. If distance between constant pressure lines is reduced by one-half, wind speed will be doubled. Conversely, if distance between lines is doubled, wind speed will be reduced by one-half. 

Reduction in water pressure between a pump or hydrant and a nozzle due to expenditure of pressure energy required to move water through a hose; includes losses due to back pressure, friction loss, elevation loss, and/or losses in fittings.

The distribution of surface atmospheric pressure features over an area of the earth as shown on a weather map. Surface pressure features include lines of constant pressure (isobars), highs, lows, and pressure gradient. The pressure pattern is directly related to wind speeds and directions at specific locations. 

Activities in advance of fire occurrence to ensure effective suppression action. Includes planning the organization, recruiting and training, procuring equipment and supplies, maintaining fire equipment and fire control improvements, and negotiating cooperative and/or mutual aid agreements. 

The use of water, foam or retardant along a control line in advance of the fire. Often used where ground cover or terrain is considered best for control action.

Activities directed at reducing the incidence of human-caused wildfires, including public education, law enforcement, personal contact, and other actions taken to reduce ignitions.

A program identified by the Clean Air Act to prevent air quality and visibility degradation and to remedy existing visibility problems. Areas of the country are grouped into 3 classes which are allowed certain degrees of pollution depending on their uses. National Parks and Wilderness Areas meeting certain criteria are "Class I" or "clean area" in that they have the smallest allowable increment of degradation. 

Provides support to fire prevention and wildland fire educational needs preceding and during periods of high wildland fire danger or prescribed fire activity. The teams provide assistance to wildland fire managers with coordination of fire loss mitigation efforts with public, state or local agencies.

Indicates that the capability is the primary capability for the equipment or aircraft.

Individual’s primary email

A lookout point that must be staffed to meet planned minimum seen area coverage in a given locality. For that reason, continuous service is necessary during the normal fire season and the lookout (person) is not sent to fires.

Individual’s primary phone.

The six-digit National Weather Station ID for the National Fire Danger Rating System (NFDRS) weather station that best represents the predominate weather and climate conditions for the incident site at the time of initial response.

Filling pump with water when pump is taking water not under a pressure head. Necessary for centrifugal pumps.

A number representing the chance that a given event will occur. The range is from 0% for an impossible event, to 100% for an inevitable event.

A forecast of the probability of occurrence of one or more of a mutually exclusive set of weather contingencies as distinguished from a series of categorical statements.

The chance that a firebrand will cause an ignition when it lands on receptive fuels.

A level of certainty corresponding to being more likely true than not.

Agency personnel with specific delegation of procurement authority, acting within the limits of agency policy of said authority.

Functional unit within the Finance/Administration Section responsible for managing all financial matters pertaining to vendor contracts.

A hose lay in which double shutoff wye (Y) valves are inserted in the main line at intervals and lateral lines are run from the wyes to the fire edge, thus permitting continuous application of water during extension of the lay.

A system of organizing workers to build fireline in which they advance without changing relative positions in line.

Allows identification of an activity which is unlawful or otherwise prohibited (burn ban, unpermitted, etc.) by local authorities.

An application of fire danger rating to support regulation of contractors involved in land management activities for fire prevention purposes in California.

Equivalent to Fire Name.

The specific results expected from completing a project.

An estimate of the direction in which the incident is expected to spread, migrate, or expand within a specified time frame.