A fire in the crowns of trees in which trees or groups of trees torch, ignited by the passing front of the fire. The torching trees reinforce the spread rate, but these fires are not basically different from surface fires.

A NIMS resource classification that refers to capability of a specific kind of resource to which a metric is applied to designate it as a specific numbered class.

Change of an atmospheric variable (temperature unless specified otherwise) with height.

A geographical area in which a task force/strike team leader or supervisor of a single resource is assigned authority and responsibility for the coordination of resources and implementation of planned tactics. A segment may be a portion of a division or an area inside or outside the perimeter of an incident. Segments are identified with Arabic numbers, i.e., A-1, etc. and are not to be used as radio designators. 

Wind speed within a stand at about eye level.

A written demand for a specific amount of money or other objects of value, other than ordinary obligations incurred for services, supplies, or things.

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

A group of 7-10 highly skilled personnel specifically associated with the planning and implementation of planned and unplanned wildland fire and hazardous fuels treatments. May be classified as a Type 1 or Type 2 dependent on qualifications and experience.

The amount of fuel present expressed quantitatively in terms of weight of fuel per unit area. This may be available fuel (consumable fuel) or total fuel and is usually dry weight.

Operational area on which firefighters combat a fire.