Subj : Wx Terms (W)(3) To : All From : Daryl Stout Date : Sun Sep 24 2017 12:09 am Wind Chill Advisory The National Weather Service issues this product when the wind chill could be life threatening if action is not taken. The criteria for this warning varies from state to state. Wind Chill Factor Increased wind speeds accelerate heat loss from exposed skin. No specific rules exist for determining when wind chill becomes dangerous. As a general rule, the threshold for potentially dangerous wind chill conditions is about -20øF. Wind Chill Warning The National Weather Service issues this product when the wind chill is life threatening. The criteria for this warning varies from state to state. Wind Couplet An area on the radar display where two maximum wind speeds are blowing in opposite directions. Wind Direction The true direction from which the wind is blowing at a given location (i.e., wind blowing from the north to the south is a north wind). It is normally measured in tens of degrees from 10 degrees clockwise through 360 degrees. North is 360 degrees. A wind direction of 0 degrees is only used when wind is calm. Wind Field The three-dimensional spatial pattern of winds. Wind Gust Rapid fluctuations in the wind speed with a variation of 10 knots or more between peaks and lulls. The speed of the gust will be the maximum instantaneous wind speed. Wind Radii Term used in National Weather Tropical Cyclone Forecast Advisory products (TCM). Wind radii are the largest radii of that wind speed found in that quadrant. Quadrants are defined as NE (0-90), SE (90-180), SW (180-270), and NW (270-0). As an example, given maximum 34 knot radii to 150 nm at 0 degrees, 90 at 120 degrees, and 40 nm at 260 degrees, the following line would be carried in the forecast/advisory: 150NE 90SE 40SW 150NW. Wind Rose A diagram, for a given locality or area, showing the frequency and strength of the wind from various directions. Wind Shear The rate at which wind velocity changes from point to point in a given direction (as, vertically). The shear can be speed shear (where speed changes between the two points, but not direction), direction shear (where direction changes between the two points, but not speed) or a combination of the two. Wind Shear Profile The change in wind speed and/or direction usually in the vertical. The characteristics of the wind shear profile are of critical importance in determining the potential for and type of severe weather. Wind Shift A change in wind direction of 45 degrees or more in less than 15 minutes with sustained wind speeds of 10 knots or more throughout the wind shift. Wind Shift Line A long, but narrow axis across which the winds change direction (usually veer). Wind Sock A tapered fabric shaped like a cone that indicates wind direction by pointing away from the wind. It is also called a "wind cone." Wind Speed The rate at which air is moving horizontally past a given point. It may be a 2-minute average speed (reported as wind speed) or an instantaneous speed (reported as a peak wind speed, wind gust, or squall). Wind Waves Local, short period waves generated from the action of wind on the water surface (as opposed to swell). Commonly referred to as waves. In a National Weather Service Coastal Marine Forecast or Offshore Forecast, wind waves are used when swells are described in the forecast. or Waves generated by the local wind blowing at the time of observation. Windward The side toward the wind. Compare with leeward. Windy 20 to 30 mph winds. WINT winter Winter Typically the coldest season of the year during which the sun is farthest from overhead. In the Northern Hemisphere, winter customarily includes the months of December, January and February. Winter Pool The pool, or height of the water surface, of a reservoir during the winter. This pool is usually a specific height and is maintained for the control of late winter and spring flooding. Winter Solstice The time at which the sun is farthest south in the Southern Hemisphere, on or around December 21. Winter Storm Warning This product is issued by the National Weather Service when a winter storm is producing or is forecast to produce heavy snow or significant ice accumulations. The criteria for this warning can vary from place to place. Winter Storm Watch This product is issued by the National Weather Service when there is a potential for heavy snow or significant ice accumulations, usually at least 24 to 36 hours in advance. The criteria for this watch can vary from place to place. Winter Weather Advisory This product is issued by the National Weather Service when a low pressure system produces a combination of winter weather (snow, freezing rain, sleet, etc.) that present a hazard, but does not meet warning criteria. Wire Weight Gage In hydrologic terms, a river gage comprised of a weight which is lowered to the water level. The weight is attached to a cable; and as the weight is lowered, a counter indicates the length of cable released. The stage is determined from the length of cable required to reach the water level. WK Weak WKN Weaken WL Will WLY Westerly WMC World Meteorological Center(s) WMO World Meteorological Organization (UN) WND Wind Wolf Number A historic term for Sunspot Number. In 1849, R. Wolf of Zurich originated the general procedure for computing the sunspot number. Wrapping Gust Front A gust front which wraps around a mesocyclone, cutting off the inflow of warm moist air to the mesocyclone circulation and resulting in an occluded mesocyclone. WRCC Western Regional Climate Center WRM Warm WRMFNT Warm Front WRN Western WRNG Warning WSFO Weather Service Forecast Office WSHFT Wind Shift WSPD On a buoy report, the wind speed (m/s) averaged over an eight-minute period for buoys and a two-minute period for land stations. Reported Hourly. WSR-57 A NWS Weather Surveillance Radar designed in 1957. It used to be part of weather radar network. It was replaced by WSR-88D units. WSR-74 A NWS Weather Surveillance Radar designed in 1974. It used to be part of weather radar network. It was replaced by WSR-88D units. WSR-88D Weather Surveillance Radar - 1988 Doppler; NEXRAD unit. WSR-88D System The summation of all hardware, software, facilities, communications, logistics, staffing, training, operations, and procedures specifically associated with the collection, processing, analysis, dissemination and application of data from the WSR-88D unit. --- þ Synchronet þ The Thunderbolt BBS - wx1der.dyndns.org .