The probable moisture content of fast-drying fuels which have a timelag constant of 1 hour or less; such as, grass, leaves, ferns, tree moss, pine needles, and small twigs (0-1/4").

The relative difficulty of constructing control line as determined by the fuel, topography, and soil.

A low expansion foam type with some bubble structure and moderate drain time, exhibiting properties of both wet and dry foam types, which is used for extinguishment, protection, and mopup.

Angle between the flame at the leading edge of the fire front and the ground surface, expressed in degrees.

Fire spreading, or ignited to spread, into (against) the wind or downslope. A fire spreading on level ground in the absence of wind is a backing fire.

The act of setting fire to unburned fuels located between the control line and main fire in burning out operations.

A two-character code to describe each measurement taken at a weather station.

Contain a fire along a flank of the fire and begin containing it across the head. Refers to ground or air attack.

Wind blowing from water to land.

A mobile weather data collection and forecasting system consisting of a communications module, weather observing module, and data interigation module. Used by incident meteorologists on an incident.