NWCG Glossary of Wildland Fire (PMS 205)

The amount of sunlight exposed to the fuels.

Photovolaticis (PV) or concentrating solar power (CSP) systems

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.

Supporting documentation on process used to map the WUI

Land management agency with responsibility for creating and administering the data.

Depth in feet of the water source.

Capacity in gallons of the water source.

A link to documentation about the mapping effort

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.

An ignition that occurs when materials geneate heat internally, often due to chemical reactions, leading to a fire without an external spark or flame.

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.

Behavior of a fire producing sparks or embers that are carried by the wind and which start new fires beyond the zone of direct ignition by the main fire.

Water applied through an orifice in finely divided particles to absorb heat and smother fire, to protect exposures from radiated heat, and to carry water toward otherwise inaccessible fire.

A rating of the forward rate of spread of the head of a fire.

A number used to indicate relative (not actual) rate of spread.

Device for combining measured ratings of various fire danger factors into numerical classes or rates of spread.

A textile yarn spun and twisted from staple-length fiber, either natural or synthetic.

A small ridge which extends finger-like from a main ridge.

Sudden increase in wind speed to at least 17 mph (15 knots) that is sustained for at least 1 minute but not more than 5 minutes.

Any nonfrontal line or narrow band of active thunderstorms extending across the horizon. It is of importance to fire behavior due to accompanying strong gusty winds and the possibility of such a line passing between regular weather observation stations without being reported.

Condition of the atmosphere in which the temperature decrease with increasing altitude is less than the dry adiabatic lapse rate. In this condition, the atmosphere tends to suppress large-scale vertical motion.