Resultant of all fire danger factors that vary from day to day, month to month, or year to year (e.g., fire weather, fuel moisture content, condition of vegetation, variable risk).

According to the American Meteorological Society, the process of transport of an atmospheric property solely by the mass motion of the atmosphere; also the rate of change of the value of the advected property at a given point.

Chemical that, when applied to a living plant, causes or accelerates drying of its aerial parts; used to facilitate burning of living vegetation by substantially lowering fuel moisture content within a few hours.

Plot of the actual dry-bulb temperature against height above the earth's surface, most commonly determined by a RAWINSONDE observation.

The amount of fire related destruction to combustible objects determined by comparing opposing sides of an object.

The effective life span of foam bubbles.

The moisture content of the 1,000-hour timelag fuels.

The moisture content of the 100-hour timelag fuels.

Fire that burns loose debris on the surface, which includes dead branches, leaves, and low vegetation.

An on-going process of gathering information by observation and by communication with others. This information is integrated to create an individual's perception of a given situation.