The fuel moisture content, weighed over all the fuel classes, at which the fire will not spread.

Angle or bearing 180 degrees opposite of azimuth.

Ignition of fuels by dropping incendiary devices or materials from aircraft.

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

Unit of fluid viscosity in fire retardant, defined as tangential force per unit area (dynes/square centimeter) required to maintain unit difference in velocity (1 centimeter/second) between two parallel planes separated by 1 cm of fluid (1 poise=1 dyne-second/cubic centimeter). 

Fire hose coupling with American National Standard (NH) threads.

A hose lay in which double shutoff wye (Y) valves are inserted in the main line at intervals and lateral lines are run from the wyes to the fire edge, thus permitting continuous application of water during extension of the lay.

An appraisal of the interaction of hazard, exposure, and effects to a given set of values in a given area.

The average maximum vertical extension of flames at the leading edge of the fire front. Occasional flashes that rise above the general level of flames are not considered. This distance is less than the flame length if flames are tilted due to wind or slope. 

Situation Unit staff collect, process, and organize situation information, prepare situation summaries, produce maps, and develop projections and forecasts related to the incident. They gather and disseminate information for incident and agency decision processe.