NWCG Glossary of Wildland Fire, PMS 205

The temperature and relative humidity of the boundary layer.

According to the American Meteorological Society, the layer of air near a boundary that is affected by friction against that boundary surface, and possibly by transport of heat and other variables across that surface.

According to the American Meteorological Society, the bottom layer of the troposhpere that is in contact with the surface of the earth. It is often turbulent and is capped by a statically stable layer of air or temperature inversion.

The equilibrium moisture content (EMC) commensurate with the boundary conditions and precipitation events of the preceding 24 hours.

A neoprene tank designed for attachment to the landing skid frame of a helicopter. It has a capacity of 80 to 100 gallons (303 to 378 liters) of water or retardant.

A steep-sided, dead end canyon.

A mechanical system used to slow down, stop or control the motion of a moving object by applying friction or force.

The organizational level having functional or geographical responsibility for major aspects of incident operations. A Branch falls between the Section Chief and the division or group in the Operations Section, and between the section and units in the Logistics Section. Branches are identified by Roman numerals or by functional area.

To insert a gate valve or some other device into a hose line.

To detach two pieces of hose by backing the swivel thread off the nipple thread.

Means "turn" left or right. Applies to aircraft in flight, usually on the drop run, and when given as a command to the pilot, implies expectation of prompt compliance.

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

Amount of heat required to raise 1 pound of water 1 degree Fahrenheit (from 59.50 to 60.50 F), measured at standard atmospheric pressure.

Prescribed burning activity where fire is applied generally to most or all of an area within well defined boundaries for reduction of fuel hazard, as a resource management treatment, or both.

Application of herbicide to desiccate living vegetation prior to burning.

Prescribed fire to control fungal infection (brown spot disease) of longleaf pine (Pinus palustris) in the "grass" (small seedling) stage.

A collective term that refers to stands of vegetation dominated by shrubby, woody plants, or low growing trees, usually of a type undesirable for livestock or timber management.

Blade attachment with long teeth specially suited to ripping and piling brush with minimum inclusion of soil.

A fire burning in vegetation that is predominantly shrubs, brush, and scrub growth.

A heavy cutting tool designed primarily to cut brush at the base of the stem. Used in much the same way as an axe and having a wide blade, generally curved to protect the blade from being dulled by rocks.

Manipulation of stands of brush by manual, mechanical, chemical, or biological means or by prescribed burning for the purpose of achieving land management objectives.

Any light, mobile vehicular unit with limited pumping and water capacity for off-road operations.

The building block of foam; bubble characteristics of water content and durability influence foam performance.

The dropping of fire retardants or suppressants from specially designed buckets slung below a helicopter.

Sawing through the bole of a tree after it has been felled.

The cumulative effects of long-term drying on current fire danger.

The increase in strength of a fire management organization.

The accelerated spreading of a fire with time.

Towering cumulus clouds which may lead to thunderstorms later in the day.

A relative measure of the cumulative effect of daily drying factors and precipitation on fuels with a ten-day timelag.

Weight per unit volume. For fuels, this is usually expressed as pounds per cubic foot; for soils, grams per cubic centimeter.

A general alert from an NWCG committee to the wildland fire community regarding the release of subject-specific information such as technical information, equipment updates, accident reports, etc. Depending on the origin and/or the subject content, a green hash-marked bordered stationary may be associated with this type of alert.

Progressive method of fireline construction on a wildfire without changing relative positions in the line. Work is begun with a suitable space between workers; whenever one worker overtakes another, all of those ahead move one space forward and resume work on the uncompleted part of the line. The last worker does not move ahead until work is completed in his/her space. Forward progress of the crew is coordinated by a crew boss. 

A fire in progress or under investigation.

An area burned over by wildland fire.

To consume fuel during rapid combustion.

A reference to a working fire.

An injury to flesh caused by a cauterizing agent, heat from a fire, or a heated object.

To be on fire.

A discrete area within a larger prescribed or fire use project.

Setting fire inside a control line to consume fuel between the edge of the fire and the control line.

The duration of flaming and smoldering combustion phases at a specified point within a burn or for the whole burn, expressed in convenient units of time.

The characteristic configuration of char left by a fire. In wildland fires burn patterns are influenced by topography, wind direction, length of exposure, and type of fuel. Definitions are scale-dependent: (1) They can be used to trace a fire's origin; (2) They are influenced by severity and intensity within a stand; (3) They describe the landscape mosaic.

Apparent and obvious design of burned material and the burning path from the area of origin.

A qualitative assessment of the heat pulse directed toward the ground during a fire. Burn severity relates to soil heating, large fuel and duff consumption, consumption of the litter and organic layer beneath trees and isolated shrubs, and mortality of buried plant parts. 

BAER teams are formed to analyze post-fire conditions and to take immediate emergency stabilization action to prevent loss of life and property and critical and natural resources. It is the Agency Administrator’s responsibility to order or designate a BAER Team.

The post-fire activities prescribed and implemented to rehabilitate and restore fire damaged lands.

Decomposition of material by the application of heat and oxidation. Also applied to propellants and other pyrotechnic mixtures, though the proper term there is "reacting". Also often an element of the crime of arson.