NWCG Glossary of Wildland Fire (PMS 205)

Term	Steward	Status	Definition
wind direction	IWSC Incident Weather Subcommittee	Approved	Compass direction from which wind is blowing.
wind profile	IWSC Incident Weather Subcommittee	Approved	A chart of wind speed in relation to height, most commonly determined by a pilot balloon observation.
wind shear	IWSC Incident Weather Subcommittee	Approved	A variation in wind speed and/or direction in a layer of the atmosphere or between layers. The variation may be in the horizontal or vertical dimensions and may result in significant turbulence depending upon the magnitude of the wind speed/direction differences. A strong wind shear may act like an inversion and inhibit plume rise. It may also fracture the smoke plume, not allowing smoke to rise much above terrain levels. A strong horizontal anticyclonic shear results in downward motion and may bring smoke aloft to the surface.
wind shift (aviation)	IWSC Incident Weather Subcommittee	Approved	For aviation purposes, a change in the average wind direction of 45 degrees or more which takes place in less than 15 minutes if the wind speed during this period is 6 knots (3 m/s) or greater.
wind shift (ground observation)	IWSC Incident Weather Subcommittee	Approved	For ground observation purposes, a change of at least 45 degrees in the direction of a significant wind, which occurs in a relatively short time frame.
wind speed (open ground)	IWSC Incident Weather Subcommittee	Approved	Wind, in miles per hour, measured at 20 feet above open, level ground or as adjusted to meet this standard to compensate for height of ground cover, uneven ground, and nearby obstructions.
wind speed (velocity)	IWSC Incident Weather Subcommittee	Approved	Wind, in miles per hour, measured at 20 feet above ground, or above the average height of vegetation, and averaged over at least a 10-minute period.
wind vectors	IWSC Incident Weather Subcommittee	Approved	Wind directions used to calculate fire behavior.
wind vortex flame wrap	FISC Fire Investigation Subcommittee	Approved	A char pattern that is created by the passage of wind around the trunk of a tree or pole-like object that creates vortices on the lee side and an area of stability.&nbsp; The area of stability allows the heat and char pattern to rise higher on the lee side of the object.&nbsp; Generally, the stronger the wind, the higher the wind vortex flame wrap will be.&nbsp; White this is not a fire pattern indicator, it is a general indication of the direction of the wind at the time the pattern was created.
wind-driven wildland fire	FASC Fire Analysis Subcommittee	Approved	A wildland fire that is controlled by a strong consistent wind.
windfall	TFSC Tree Felling Subcommittee	Approved	Tree that has been uprooted or broken off by wind.
windrow burning	FMSC Fuels Management Subcommittee	Approved	Burning slash that has been piled into long continuous rows. Also includes wildfire in vegetation planted to protect improvements or agriculture.
winds aloft	IWSC Incident Weather Subcommittee	Approved	Generally, wind speeds and wind directions at various levels in the atmosphere above the domain of surface weather observations.
windspeed meter	IWSC Incident Weather Subcommittee	Approved	A handheld device which indicates wind speed, usually in miles per hour.
woody fuel moisture	IWSC Incident Weather Subcommittee	Approved	In NFDRS, a calculated value representing the approximate moisture content of the live woody vegetation in the rating area expressed as a percentage of the oven dry weight of the sample.
woody vegetation condition	IWSC Incident Weather Subcommittee	Approved	A code reflecting the moisture content of the foliage and small twigs [less than 1/4 inch (0.6 cm)] of living woody plants.
Work Capacity Test (WCT)	SRC Safety/Risk Management Committee	Approved	A test to ensure a person is physically capable of meeting the minimum fitness requirement associated with assigned wildfire or prescribed fire duties as described in the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1.
work capacity test levels	SRC Safety/Risk Management Committee	Approved	The WCT consists of three separate levels of tests which correspond with the three duty types. The tests are defined as Pack Test, Field Test, Walk Test.
work rate	FBC Finance/Business Management Committee	Approved	A daily, hourly, or mileage rate shall apply when equipment is under hire as ordered by the government and on shift, including relocation of equipment under its own power.
work/rest ratio	SRC Safety/Risk Management Committee	Approved	An expression of the amount of rest that is required for each hour an individual is in work status. Current NWCG guidelines require one hour of rest for every two hours in work status.
Working Pressure (WP)	ETSC Equipment/Technology Subcommittee	Approved	The maximum &ldquo;operating pressure&rdquo; of a component or system. Identified as &ldquo;WP&rdquo; on Forest Service-qualified fire hose. Also known as &ldquo;rated pressure'.
woven jacket fire hose	ETSC Equipment/Technology Subcommittee	Approved	Fire hose of conventional construction, woven on looms from fibers of cotton or synthetic fibers. Most fire department hose is double jacketed (i.e., it has an outer jacket protecting the inner one against wear and abrasion).
wye	ETSC Equipment/Technology Subcommittee	Approved	A hose connection with two outlets permitting two connections of the same coupling diameter to be taken from a single supply line.
yarn number (cotton)	MFES Mobile Fire Equipment Subcommittee	Approved	A conventional relative measure of fineness as applied to yarns. Coarse yarns have low numbers and fine yarns have high numbers.
zone weather forecast	IWSC Incident Weather Subcommittee	Approved	A portion of the general fire weather forecast issued on a regular basis during the normal fire season specifically to fit the requirements of fire management needs; i.e., time, areas, and weather elements. These zones or areas are a combination of administrative and climatological areas, usually nearly the size of an individual forest or district.&nbsp;

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