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National Wildfire Coordinating Group (NWCG)

Glossary of Wildland Fire Terminology


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Macro Scale Indicators

  1. Large single indicators or overall patterns of indicators that are readily visible from a distance.

Macroclimate

  1. General large-scale climate of a large area or country as distinguished from smaller scale mesoclimate and microclimate.

Main Ridge

  1. Prominent ridgeline separating river or creek drainages. Usually has numerous smaller ridges (spur) extending outward from both sides.

Major Disaster

  1. Any natural catastrophe or, regardless of cause, any fire, flood, or explosion, in any part of the United States, which in the determination of the President causes damage of sufficient severity and magnitude to warrant major disaster assistance.

Major Repair (Aviation)

  1. A repair (1) that, if improperly done, might appreciably affect weight, balance, structural strength, or other qualities affecting airworthiness or (2) that is not done according to accepted practices or cannot be done by elementary operations.

Male Coupling

  1. An externally threaded hose nipple which fits in the thread of a female (internally threaded) swivel coupling of the same pitch and diameter. Nozzles attach to this type of coupling.

Management Action Points

  1. Geographic points on the ground or specific points in time where an escalation or alternative of management actions is warranted. These points are defined and the management actions to be taken are clearly described in an approved Wildland Fire Implementation Plan (WFIP) or Prescribed Fire Plan. Timely implementation of the actions when the fire reaches the action point is generally critical to successful accomplishment of the objectives. Also called Trigger Points.

Management by Objectives

  1. In ICS, this is a top-down management activity which involves a three-step process to achieve the incident goal. The steps are: establishing the incident objectives, selection of appropriate strategy(s) to achieve the objectives; and the tactical direction associated with the selected strategy. Tactical direction includes: selection of tactics, selection of resources, resource assignments and performance monitoring.

Managers

  1. Individuals within ICS organizational units that are assigned specific managerial responsibilities, e.g., staging area manager or camp manager.

Manual Weather Station

  1. A non-telemetered weather station that provides one observation every 24 hours for manual entry into WIMS.

see also: Automatic Weather Station

Manually Regulated

  1. A proportioning method or device that requires a manual adjustment to maintain a desired mix ratio over a changing range of water flows and pressures.

Marine Air

  1. Air which has a high moisture content and the temperature characteristics of an ocean surface due to extensive exposure to that surface. An intrusion of marine air will moderate fire conditions. Absence of marine air in coastal areas may lead to more severe fire danger.

Marine Climate

  1. Regional climate under the predominant influence of the sea, that is, a climate characterized by marine air; the opposite of a continental climate.

Maritime Air

  1. Air which has assumed high moisture content and the temperature characteristics of a water surface due to extensive exposure to that surface.

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Mass Arsonist

  1. An offender who sets three or more fires at the same location during a limited period of time.

Mass Fire

  1. A fire resulting from many simultaneous ignitions that generates a high level of energy output.

Master Fire Chronology

  1. Chronological listing of the dates of fires documented in a designated area, the dates being corrected by crossdating. Size of the area must be specified. Also called composite fire interval.

Material First Ignited

  1. The fuel that is first set on fire by the heat of ignition; to be meaningful, both a type of material and form of material should be indentified.

Mathematical Model

  1. A model that is a quantitative and mathematical representation or simulation which attempts to descibe the characteristics or relationship of physical events.

see also: Model

Mattock

  1. Hand tool with a narrow hoeing surface at one end of the blade and a pick or cutting blade at the other end; used for digging and grubbing.

Maximum Certified Gross Weight

  1. Absolute maximum allowable gross weight for an aircraft as established by the manufacturer and approved by the FAA.

Maximum Computed Gross Weight

  1. Computed gross weight for an aircraft, obtained from the appropriate performance chart, which is the maximum gross weight appropriate to the applicable circumstance of configuration and/or environmental conditions.

Maximum Dry Bulb Temperature

  1. The highest value for dry bulb temperature measured at the observation site during the preceding 24-hour period.

see also: Minimum Dry Bulb Temperature

Maximum Management Area (MMA)

  1. The maximum geographic limits of spread within which a wildland fire use fire is allowed to spread.

Maximum Relative Humidity

  1. The highest value for relative humidity measured at the observation site during the preceding 24-hour period.

see also: Minimum Relative Humidity

May Day

  1. International distress signal/call. When repeated three times it indicates imminent and grave danger and that immediate assistance is required.

Mcleod

  1. A combination hoe or cutting tool and rake, with or without removable blades.

Mean Fire Return Interval

  1. Arithmetic average of all fire intervals in a given area over a given time.

Mean Sea Level (MSL)

  1. Average height of the surface of the sea for all stages of the tide over a 19-year period. NOTE: when the abbreviation MSL is used in conjunction with a number of feet, it implies altitude above sea level (e.g., 1000 feet MSL).

Measured Woody Fuel Moisture

  1. Moisture content of the small branch wood and foliage of live woody plants, expressed as a percentage of the oven dry weight of the sample, collected monthly and used to supplement NFDRS modeled outputs.

see also: Woody Fuel Moisture

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Medical Director

  1. A physician who assumes the ultimate responsibility for the patient care aspects of the incident EMS program.

Medical Unit

  1. Functional unit within the logistics section that is responsible for the emergency medical and occupational health care of incident personnel. Some incident management teams have placed this unit under safety.

Medical Unit Leader (MEDL)

  1. The ICS position responsible for supervising the Medical Unit. Reports to the Service Branch Director or Logistics Section Chief.

see also: Medical Unit

Medium Expansion

  1. Foam with an expansion between 21:1 and 200:1.

Medium-range Forecast

  1. A forecast for a period extending from about two days to five days or a week in advance; there are no absolute limits to the period embraced by this definition.

Medivac

  1. Mobile medical treatment and transportation.

Message Center

  1. The message center is part of the incident communications center and is collocated or placed adjacent to it. It receives, records, and routes information about resources reporting to the incident, resource status, and administrative and tactical traffic.

Methodology

  1. A set of standardized procedures and practices that have been peer-reviewed and have received general acceptance by the profession.

Micro Scale Indicators

  1. Small individual indicators and patterns that are not easily observable without close observation or magnification.

Micro-Remote Environmental Monitoring System (Micro-REMS)

  1. Mobile weather monitoring station. Each unit consists of a shipping container, solar panel, battery, temperature/relative humidity sensor, wind mast, wind direction/speed sensor, data logger and radio. A Micro-REMS usually accompanies an incident meteorologist and ATMU to an incident.

see also: Incident Meteorologist

Mid-Flame Windspeed

  1. The speed of the wind measured at the midpoint of the flames, considered to be most representative of the speed of the wind that is affecting fire behavior.

Military Operations Area (MOA)

  1. Military Operations Area found on aeronautical charts.

Military Time

  1. The 24-hour clock system where midnight is 2400, one minute after midnight is 0001 and progresses to 2400 daily.

Millibar

  1. A unit of pressure equal to a force of 1,000 dynes per square centimeter. (A dyne is the force that would give a free mass of one gram an acceleration of one centimeter per second per second.)

Mineral Ash

  1. The residue of mineral matter left after complete combustion of wood (wood ash) or other organic material; consists largely of oxides, carbonates, and phosphates of Ca, K and Mg, together with other compounds.

Mineral Soil

  1. Soil layers below the predominantly organic horizons; soil with little combustible material.

Minimum Cost Suppression Alternative

  1. The alternative that achieves incident objectives, consistent with priority for firefighter and public safety, and is least expensive when considering expected costs for fire suppression and emergency stabilization and/or rehabilitation.

Minimum Dry Bulb Temperature

  1. The lowest value for dry bulb temperature measured at the observation site during the preceding 24-hour period.

see also: Maximum Dry Bulb Temperature

Minimum Impact Suppression Techniques (MIST)

  1. The application of strategy and tactics that effectively meet suppression and resource objectives with the least environmental, cultural and social impacts.

Minimum Relative Humidity

  1. The lowest value for relative humidity measured at the observation site during the preceding 24-hour period.

see also: Maximum Relative Humidity

Miscellaneous Fire

  1. Fire of known cause that cannot be properly classified into any of the eight standard causes of fires.

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Mitigation

  1. Those activities implemented prior to, during, or after an incident which are designed to reduce or eliminate risks to persons or property that lessen the actual or potential effects or consequences of an incident. Mitigation measures can include efforts to educate governments, businesses, and the general public on measures they can take to reduce loss and injury and are often informed by lessons learned from prior incidents.

Mitigation Actions

  1. On-the-ground actions that will serve to increase the defensibility of the Maximum Management Area (MMA); check, direct, or delay the spread of fire; and minimize threats to life, property, and resources. Mitigation actions may include mechanical and physical non-fire tasks, specific fire applications, and limited suppression actions. These actions will be used to construct firelines, reduce excessive fuel concentrations, reduce vertical fuel continuity, create fuel breaks or barriers around critical or sensitive sites or resources, create "black lines" through controlled burnouts, and to limit fire spread and behavior.

Mix Ratio

  1. The ratio of liquid foam concentrate to water, usually expressed as a percent.

Mixing

  1. A random exchange of air parcels on any scale from the molecular to the largest eddy.

Mixing Chamber

  1. A tube, constructed with deflectors or baffles, that mixes foam solution and air to produce tiny, uniform bubbles in a short distance (1 to 2 ft).

Mixing Height

  1. Measured from the surface upward, the height to which relatively vigorous mixing occurs due to convection. Also called mixing depth.

Mixing Layer

  1. That portion of the atmosphere from the surface up to the mixing height. This is the layer of air, usually below a stable layer, within which pollutants are mixed by turbulence and diffusion. Also called mixed layer.

see also: Transport Wind Speed ; Ventilation Factor

Mixmaster

  1. The person in charge of fire retardant mixing operations with responsibility for quantity and quality of the slurry and for the loading of aircraft.

Mobile Radio

  1. A two way radio unit on mobile apparatus (instead of base stations), usually semi-permanently attached to the apparatus.

Mobile Weather Unit Forecast

  1. A special fire weather forecast for a specific fire prepared by a meteorologist on site at or near the fire area.
  2. A special weather forecast for a specific incident prepared by a meteorologist on site at or near the incident area.

Mobilization

  1. The process and procedures used by all organizations, federal, state and local, for activating, assembling, and transporting all resources that have been requested to respond to or support an incident.

Mobilization Center

  1. An off-incident location at which emergency service personnel and equipment are temporarily located pending assignment, release, or reassignment.

Mobilization Guide

  1. A written description of procedures used by federal, state, and local organizations for activating, assembling, and transporting resources that have been requested to respond to or support an incident.

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Model

  1. A simplified or generalized representation of reality; a description, analogy, picture, or hypothesis to help visualize something that cannot be directly observed.

see also: Conceptual Model ; Mathematical Model

Model Arson Law

  1. Model legislation, recommended by the Fire Marshals' Association of North America and adopted in most states, dealing with the subject of arson.

Model Fireworks Law

  1. Model legislation recommended by the Fire Marshals' Association of North America and adopted by many states, regulating display of fireworks.

Modular Airborne Firefighting System (MAFFS)

  1. A manufactured unit consisting of five interconnecting tanks, a control pallet, and a nozzle pallet, with a capacity of 3,000 gallons, designed to be rapidly mounted inside an unmodified C-130 (Hercules) cargo aircraft for use in cascading retardant chemicals on wildfires.

Moist Adiabatic Lapse Rate

  1. Rate of decrease of temperature with increasing height of an air parcel lifted at saturation via adiabatic process through an atmosphere in hydrostatic equilibrium. Rate varies according to the amount of water vapor in the parcel and is usually between 2.0 and 5.0 degrees F per 1000 feet (3.6 and 9.2 degrees C per 1000 meters).

Moisture of Extinction

  1. The fuel moisture content, weighed over all the fuel classes, at which the fire will not spread. Also called extinction moisture content (EMC).

Monitor

  1. A turret-type nozzle usually mounted on an engine.

Monitoring

  1. The orderly collection, analysis, and interpretation of environmental data to evaluate management's progress toward meeting objectives, and to identify changes in natural systems. Monitoring is also conducted on wildland fires to observe fire effects, fire behavior, or both. For example, the work done by Fire Effects Monitor (FEMO) or Field Observer (FOBS) positions.

Monsoon Climate

  1. Climate characterized by (a) a long winter-spring dry season which includes a "cold season" followed by a short "hot season" immediately preceding the rains, (b) a summer and early autumn rainy season which is usually very wet (but highly variable (but highly variable from year to year), and (c) a secondary maximum of temperature immediately after the rainy season.

Mop Up

  1. Extinguishing or removing burning material near control lines, felling snags, and trenching logs to prevent rolling after an area has burned, to make a fire safe, or to reduce residual smoke.

Mop Up Crew

  1. A portion or all of a regular fire crew assigned to mop up work after the fire or a portion of the fire has been contained or controlled.

Mop Up Time

  1. Elapsed time from containment or control of a fire until mop up is complete.

Mosaic

  1. The intermingling of plant communities and their successional stages in such a manner as to give the impression of an interwoven design.

Most Efficient Level (MEL)

  1. The fire management program budget level that results in the minimum cost plus net value change.

Move-up

  1. System of redistributing remaining personnel and equipment following dispatch of other forces among a network of fire stations to provide the best possible response within the fire department's direct protection area in the event of additional calls for emergency assistance.

Moveup Method

  1. Progressive method of fireline construction on a wildfire without changing relative positions in the line. Work is begun with a suitable space between workers; whenever one worker overtakes another, all of those ahead move one space forward and resume work on the uncompleted part of the line. The last worker does not move ahead until work is completed in his/her space. Forward progress of the crew is coordinated by a crew boss.

synonym: Bumpup Method

Multi-Agency Coordination (MAC)

  1. A generalized term which describes the functions and activities of representatives of involved agencies and/or jurisdictions who come together to make decisions regarding the prioritizing of incidents, and the sharing and use of critical resources. The MAC organization is not a part of the on-scene ICS and is not involved in developing incident strategy or tactics.

Multi-Agency Coordination System (MACS)

  1. MACS provides the framework to support coordination for incident prioritization, cirtical resource allocation, communication systems integration, and information coordination. MACS components include facilities, equipment, emergency operating centers EOCs), specific multi-agency coordination entities, personnel, procedures, and communications.

Multi-Agency Incident

  1. An incident where one or more agencies assist a jurisdictional agency or agencies. May be single or unified command.

see also: Jurisdiction

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Multicom

  1. A VHF/AM aircraft radio frequency (122.9 MHz) assigned by the FAA for use in air-to-air communications.

Multijurisdiction Incident

  1. An incident requiring action from multiple agencies that have a statutory responsibility for incident mitigation. In ICS these incidents will be managed under unified command.

see also: Jurisdiction

Multiple Fire Situation

  1. High fire frequency over a short period of time in an administrative unit, usually overtaxing the normal initial attack capability of the unit.

Multiple Fire-Day

  1. In FireFamily Plus, a day with both a weather observation and a number of fires equal to or greater than that determined by the user to be a significant workload.

see also: Fire-Day ; Large Fire-Day

Multiple Points of Origin

  1. Two or more separate points of fire origins at a fire scene; strong indication of arson.

Mutual Aid

  1. Assistance in firefighting or investigation by fire agencies, without regard for jurisdictional boundaries.

Mutual Aid Agreement

  1. Written agreement between agencies and/or jurisdictions in which they agree to assist one another upon request, by furnishing personnel and equipment.

Mutual Threat Zone

  1. A geographical area between two or more jurisdictions into which those agencies would respond on initial attack. Also called mutual response zone or initial action zone.

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