- An incendiary mixture with a jelling agent used in flamethrowers and bombs.
| National Ambient Air Quality Standards (NAAQS)|
- A legal limit on the level of atmospheric contamination. The level is established as the concentration limits needed to protect all of the public against adverse effects on public health and welfare, with an adequate safety margin. Primary standards are those related to health effects. Secondary standards are designed to protect the public welfare from effects such as visibility reduction, soiling, material damage and nuisances.
| National Fire Codes (NFC)|
- The collected technical fire protection standards prepared by various committees of the National Fire Protection Association and published annually in 15 volumes.
| National Fire Danger Rating System (NFDRS)|
- A uniform fire danger rating system that focuses on the environmental factors that control the moisture content of fuels.
| National Fire Protection Association Standards (NFPA)|
- Standards of the National Fire Protection Association are frequently adopted by insurance agencies such as the National Board of Fire Underwriters as a basis for their regulations and used as a guide for municipal, state, or provincial laws, ordinances, and regulations.
| National Interagency Fire Management Integrated Database (NIFMID)|
- The archive of daily weather observations from WIMS.
| National Interagency Incident Management System (NIIMS)|
- An NWCG developed program consisting of five subsystems which collectively provide a total systems approach to all-risk incident management. The subsystems are: The Incident Command System, Training, Qualifications and Certification, Supporting Technologies, and Publications Management.
| National Pipe Straight Hose Thread (NPSH)|
- This is a straight (nontapered) thread standard with the same threads per inch as the appropriate size iron pipe thread. It requires a gasket to seal and is the thread standard used by most U.S. industry. Also known as National Pipe Straight Mechanical (NPSM) thread.
| National Resource Lands (NRL)|
- Public lands administered by the Bureau of Land Management, U.S. Department of the Interior.
| National Response Plan|
- A plan that integrates federal government domestic prevention, preparedness, response, and recovery plans into one all-discipline, all-hazard plan.
| National Standard Thread (NH)|
- Abbreviated (NH) for national hose. Specifically defined screw thread used on fire hose couplings.
| Native Species|
- A species which is a part of the original fauna or flora of the area in question.
| Natural Barrier|
- Any area where lack of flammable material obstructs the spread of wildfires.
| Natural Fuels|
- Fuels resulting from natural processes and not directly generated or altered by land management practices.
| Near Miss|
- Any potential accident which, through prevention, education, hazard reduction, or luck, did not occur.
| NESDIS ID|
- An 8-character identifier assigned by NESDIS that becomes the RAWS identification number for use with the GOES satellite.
| Net Value Change (NVC)|
- The sum of the changes in the value of natural resources affected by a fire. The basis for computing NVC is each resource's fire-induced value change (pluses and minuses) as computed and expressed on a per unit basis.
| Neutral Atmosphere|
| Night (Aviation)|
- The time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the American Air Almanac, converted to local time.
| Nitrogen Dioxide (NO2)|
- The result of nitric oxide combining with oxygen in the atmosphere. A major component of photochemical smog.
| Nitrogen Oxide (NO)|
- Product of combustion from transportation and stationary sources and a major contributor to acid deposition and the formation of ground level ozone in the troposphere.
- Trade name for a fire resistant synthetic material used in the manufacturing of flight suits and pants and shirts used by firefighters. Aramid is the generic name.
| Non-attainment Area|
- An area identified by an air quality regulatory agency through ambient air monitoring (and designated by the Environmental Protection Agency), that presently exceeds federal ambient air standards.
- Material unlikely to burn when exposed to flame under most conditions.
| Nonprecision Approach Procedure|
- Standard aircraft instrument approach procedure in which no electronic glide slope is provided.
| Nonstatistical Fire|
- Any fire not posing a threat to resources or property of the jurisdictional agency, regardless of whether action was taken by the agency.
| Normal Fire Season|
- A season when weather, fire danger, and number and distribution of fires are about average.
- Period of the year that normally comprises the fire season based on historical fire occurrence.
| Normalized Difference Vegetation Index (NDVI)|
- A satellite observation-derived value that is sensitive to vegetative growth, measured at 1.1 km (0.6 mile) spatial and 1 week temporal scales.
| Notice to Airmen (NOTAM)|
- Notice identified as either a NOTAM or Airmen Advisory containing information concerning the establishment, condition, or change in any component of, or hazard in, the National Airspace System, the timely knowledge of which is essential to personnel concerned with flight operations.
| Nozzle Aspirated Foam System|
- A foam generating device that mixes air at atmospheric pressure with foam solution in a nozzle chamber.
| Nozzle Operator|
- A person assigned to operate a fire hose nozzle, usually on a handline.
| NWCG Standard|
- A defined behavior, action, process, or equipment type, agreed upon by the National Wildfire Coordinating Group for wildland fire performance, and is necessary to meet consistent, interagency fire management activities.