A progressive system of building a fireline on a wildfire without changing relative positions in the line. Each worker does one to several "licks", or strokes, with a given tool and then moves forward a specified distance to make room for the worker behind.

Rate at which a propellant and other combustibles burn.

Prediction of probable fire behavior, usually prepared by a fire behavior analyst, in support of fire suppression or prescribed burning operations.

A NIMS guiding principle stating that each individual involved in incident management reports to and takes direction from only one person.

An increase in the central pressure of a low. Counter-clockwise wind flow around the low usually decreases as filling occurs.

An airborne dust, fume, gas, mist, odor, smoke, vapor, soot, pollen, carbon, acid or particulate matter or any combination thereof.

The general term referring to the undesirable addition of substances (gases, liquids, or solid particles) to the atmosphere that are foreign to the natural atmosphere or are present in quantities exceeding natural concentrations.

Graph showing the increase in temperature at a specified point in a fire as a function of time, beginning with ignition and ending with burnout.

The speed of an aircraft as shown on its pitot static airspeed indicator. Calibrated to reflect standard atmosphere adiabatic compressible flow at sea level, uncorrected for airspeed system errors.

A permanent source of air pollution that can be distinctly identified such as a smokestack.