NWCG Glossary of Wildland Fire (PMS 205)

A series of lines of fire ignited near and up wind (or downslope) of a firebreak or backing fire so they burn with the wind (or upslope) toward the firebreak or backing fire.

The protection of homes or other structures from an active wildland fire.

When flames from a burning building or other structure extend beyond the immediate area and ignite surrounding vegetation.

A constructed object, usually a free-standing building above ground.

The arrangement of vegetation in terms of density, basal area, cover, and vertical arrangement.

An event dealing with a major accident or mishap such as collapse of a building or other man-made structure.

Fire originating in and burning any part or all of any building, shelter, or other structure.

An event dealing with a fire originating in and burning any part or an entire building, shelter, or other structure.

Ignition resulting from failures or activites associated with residential or other structures.

The characteristics of a structure and its immediate surroundings within 100 feet; the SIZ may be extended (e.g., to 150 or 200 feet) in areas of steep terrain or dense, highly flammable vegetation. The SIZ is the key determinant for structure ignition potential during wildfire.

A plan developed by the Structure Protection Specialist that provides operational guidelines to suppression resources responsible for providing wildland fire structure protection.

Data that specifies the relationships between data elements and data groups.

Downward or sinking motion of air in the atmosphere. Subsiding air warms due to compression. Increasing temperature and decreasing humidities are present in subsiding air. Subsidence results in a stable atmosphere inhibiting dispersion. Subsidence is generally associated with high atmospheric pressure. 

An inversion caused by subsiding air, often resulting in decreased atmospheric mixing conditions.

Damage or failure which adversely affects the structural strength,performance, or flight characteristics of the aircraft, and which would normally require major repair or replacement of the affected component. Engine failure or damage limited to an engine if only one engine fails or is damaged, bent fairings or cowling, dented skin, small punctured holes in the skin or fabric, ground damage to rotor or propeller blades, and damage to landing gear, wheels, tires, flaps, engine accessories, brakes, or wingtips are not considered “substantial damage” for the purpose of this part.
 
(See 49 CFR (NTSB) 830/831)

The process of vegetational development whereby an area becomes successively occupied by different plant communities of higher ecological order.

In fire service, the number of feet (meters) of vertical lift from the surface of the water to the center of the pump impeller. In testing, e.g., fire department pumpers are required to discharge their rated capacity at 150 pounds (1034 kPa) net pump pressure at a 10-foot (3 meter) lift. The suction gauge would indicate the vertical suction lift in inches of mercury when the pump was primed with no appreciable water flowing. 

The adjective classification of the sky when 5/10 or less of the sky is obscured by clouds.

The mean solar times of sunset and sunrise as published in the Nautical Almanac, converted to local standard time for the locality concerned.

A minor thermal burn involving the outer layer of skin, i.e. "a sunburn". It is characterized by reddening of the skin and perhaps some swelling without blisters.

An extremely dense surface fog (water droplets suspended in the atmosphere) at the site of combustion that reduces visibility to less than three meters (ten feet).

The ICS title for an individual responsible for a division or group.

Overhead tied to a local fire department, generally by agreement, who are mobilized primarily for response to incidents or wildland fires outside their district or mutual aid zone. Supplemental fire department resources are not a permanent part of the local fire organization and are not required to attend scheduled training, meetings, etc. of the department staff. 

Minor items of equipment and all expendable items assigned to an incident.

Supply Unit staff order, receive, process, store, inventory, and distribute all incident-related supplies. The Supply Unit staff are responsible for all off-incident ordering.

A branch within the logistics section responsible for providing personnel, equipment and supplies to support incident operations. Includes the supply, facilities and ground support units.

On-incident costs and off-incident costs. On-incident costs include caterer, shower units, mobile commissary, cache supplies, and materials, etc. Off-incident costs include expanded dispatch, buying teams, administrative payment teams, cache personnel, area command, transportation to/from incident, etc. 

Non-tactical resources under the supervision of the logistics, planning, finance/administration sections or the command staff.

An agency providing suppression or other support and resource assistance to a protecting agency.

Any technology which may be used to support NIIMS. Examples of these technologies include GIS mapping, infrared technology, NFDRS, communications, dispatch coordination, and national cache system.

see: Suppression

An agent that extinguishes the flaming and glowing phases of combustion by direct application to the burning fuel.

All the work to extinguish or limit wildland fire spread.

Two or more firefighters stationed at a strategic location for initial action on fires. Duties are essentially the same as those of individual firefighters.

Intentional application of fire to speed up or strengthen fire suppression action on wildfires. Types of suppression firing include burning out, counter firing, and strip burning.

The ratio between the surface area of an object, such as a fuel particle, to its volume. The smaller the particle, the more quickly it can become wet, dry out, or become heated to combustion temperature during a fire.

Fire that burns loose debris on the surface, which includes dead branches, leaves, and low vegetation.

Fuels lying on or near the surface of the ground, consisting of leaf and needle litter, dead branch material, downed logs, bark, tree cones, and low stature living plants.

An area on the earth's surface where atmospheric pressure is at a relative maximum. Winds blow clockwise around highs in the Northern Hemisphere but, due to friction with the earth's face, tend to cross constant pressure lines away from the high center. Air is usually subsiding above a surface high. This causes warming due to air compression. This results in stable atmospheric conditions and light surface winds. 

An area on the earth's surface where atmospheric pressure is at a relative minimum. Winds blow counter-clockwise around lows in the Northern Hemisphere but, due to friction with the earth's surface, tend to cross constant pressure lines toward the low center. Upon converging into the low's center, air currents are forced to rise. As air rises it cools due to expansion. Cooling reduces its capacity to hold moisture; so cloudiness and precipitation are common in lows. If a low center intensifies sufficiently it will take on the characteristics of a storm center with precipitation and strong winds.

The elastic-like force at the surface of a liquid, tending to minimize the surface area and causing drops to form. Expressed as Newtons per meter or dynes per centimeter (1 Newton/m=1,000 dynes/cm).

Wind measured at a surface observing station, customarily at some distance (usually 20 feet) above the average vegetative surface to minimize the distorting effects of local obstacles and terrain.

A surface active agent; any wetting agent. A formulation which, when added to water in proper amounts, will materially reduce the surface tension of the water and increase penetration and spreading abilities of the water.

Rapid increase in water flow which may result in a corresponding pressure rise.

Any excess personal property not required for the needs and the discharge of the responsibilities of all federal agencies as determined by the General Services Administration (GSA).

A natural or cleared area of sufficient size and location to protect fire personnel from known hazards while inside a fire shelter. Examples include rock slides, road beds, clearings, knobs, wide ridges, benches, dozer lines, wet areas, cleared areas in light fuels, and previously burned areas. These are all areas where you expect no flame contact or prolonged heat and smoke. 

A wildland fuel that is suspended off the ground in such a way that fire may burn both over and under it.

A measure of the refresh rate of the water source.