An airborne irritating, noxious, or toxic smoke, vapor, or any combination of these produced by a volatile substance or a chemical reaction.

Activities in advance of fire occurrence to ensure effective suppression action. Includes planning the organization, recruiting and training, procuring equipment and supplies, maintaining fire equipment and fire control improvements, and negotiating cooperative and/or mutual aid agreements. 

Technique whereby fire retardant is released from only one compartment of an airtanker.

A magnetic bearing extending from a ground-based navigational system, providing airborne navigation information.

Any fire not posing a threat to resources or property of the jurisdictional agency, regardless of whether action was taken by the agency.

Numerical rating of the potential occurrence of lightning-caused fires.

The period of combustion when a fire is spreading, usually accompanied by flaming combustion that releases heat to sustain the convection column.

Composite pattern of weather elements over time that affect fire behavior in a given region.

Wind direction which varies by 60 degrees or more during the period of time the wind direction is being determined.

The time (minutes) it takes for foam solution to drop out from the foam mass; for a specified percent of the total solution contained in the foam to revert to liquid and drain out of the bubble structure.