An area cleared to mineral soil for piling unburned fuels.

Water that contains a thickening agent to reduce surface runoff; tends to cling to burning fuels and spread in layers that are several times thicker than plain water, thereby having an increased capacity to absorb heat, cool fuel, and exclude oxygen.

A generic term used to describe foam systems consisting of an air compressor (or air source), a water pump, and foam solution.

A WIMS file that contains all the information defined for a weather station.

Any part of a fireline rendered useless by a breakover of the fire.

The leading edge of a relatively warm air mass which moves in such a way that warm air replaces colder air that moves away from a region. Winds associated with warm frontal activity are usually light and mixing is limited. The atmosphere is relatively stable when compared to cold front activity.

Amount of heat required to raise 1 pound of water 1 degree Fahrenheit (from 59.50 to 60.50 F), measured at standard atmospheric pressure.

Time used by an airtanker or helitanker to reload and return to the fire.

Status of a federal casual or federal regular government employee used for timekeeping purposes. An employee will be considered off duty and time spent in an on-call status shall not be considered hours of work if: 1) The employee is allowed to leave a telephone number or to carry an electronic device for the purpose of being contacted, even though the employee is required to remain within a reasonable call-back radius; or 2) The employee is allowed to make arrangements such that any work which may arise during the on-call period will be performed by another person.

Period(s) of the year during which wildland fires are likely to occur, spread, and affect resources values sufficient to warrant organized fire management activities.