VAD - Velocity Azimuth Display. A radar display on which mean radial velocity is plotted as a function of azimuth. See VWP.
Vault - Same as BWER.
Radial Velocity measured by Doppler radars
Doppler radars can measure the component of the velocity of targets toward or away from the radar. This component is called the "radial velocity".
Velocity Azimuth Display (VAD): This WSR-88D radar product displays a graphical plot of mean radial velocity versus azimuth angle for a particular altitude.
velocity
A vector quantity representing the time rate of the change of position. The direction of motion and the magnitude (speed) of the velocity vector must be specified.
velocity"The time rate of change of a position vector; that is, a change of position expressed in terms of speed and direction. If x is the position vector of a given point in space and t is time, the velocity, u, is given by ...
Velocity Cross Section
This WSR-88D radar product displays a vertical cross section of velocity on a grid with heights up to 70,000 feet on the vertical axis and distance up to 124 nm on the horizontal axis.
Velocity Azimuth Display - permalink - collapse
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Velocity: The change of direction and position of an object with time.
Visibility: The maximum horizontal distance at which objects can be identified.
Base Velocity - one of the three fundamental quantities (along with base reflectivity and spectrum width) that a Doppler radar measures.
Base Velocity (V) This WSR-88D radar product depicts a full 360° sweep of radial velocity data. It is available for every elevation angle that is sampled in a volume scan.
WIND VELOCITY: A vector term which includes both wind speed and wind direction.
WINDWARD: Situated on the side from which the wind blows.
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wind velocity—A vector term to include both wind direction and wind speed.
wind shear—The rate of change of wind velocity (direction and/or speed) per unit distance; conventionally expressed as vertical or horizontal wind shear.
Wind Velocity Vector term that includes both wind speed and wind direction.
RADIAL VELOCITY A type of velocity that expresses motion toward or away from a given location. In Doppler radar, it is the component of motion that is parallel to the radar beam.
Radial velocity
The component of motion toward or away from a given location. As "seen" by Doppler radar, it is the component of motion parallel to the radar beam. (The component of motion perpendicular to the beam cannot be seen by the radar.
Angular Velocity- the rate at which a spinning body rotates.
Anticyclone- a body of air in which the atmospheric pressure is higher than the pressure in the surrounding air; a high or high pressure area.
Angular Velocity- the rate at which a spinning body rotates.
Anomaly- The deviation of (usually) temperature or precipitation in a given region over a specified period from the normal value for the same region.
Nyquist Velocity or Interval: The maximum unambiguous velocity that can be measured by a Doppler radar.
Velocity anemometers may again be subdivided into two classes, (1) those which do not require a wind vane or weathercock, (2) those which do.
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Cup anemometers ...
The velocity profiles under different condtions are sketched at the left. The wind velocity above the effect of the surface is V, and z = ε is the height at which v = 0.
RELATIVE VELOCITY - The apparent speed between two objects, considering any speeds of those objects. For example, a person is driving at 55 MPH to a storm. The storm is coming at him at 30 MPH.
Vertical velocity
A measure of the upward motion of air in the atmosphere. Vertical velocities are in general around 1 cm.s-1 (compared to 10 m.s-1 for horizontal velocities), but can reach several m.s-1 in thunderstorm updrafts.
Terminal velocity The constant speed obtained by a falling object when the upward drag on the object balances the downward force of gravity.
Thermal A small, rising parcel of warm air produced when the earth's surface is heated unevenly.
Terminal velocity Constant downward-directed speed of a particle within a fluid due to a balance between gravity and fluid resistance.
Thermal inertia Resistance to a change in temperature. ...
doppler velocity (m/s)When used, the positive is down (towards the radar). Particle and air motions contribute to the velocity.downdraftDownward-moving air, usually within a thunderstorm cell.
Wind shear - a velocity gradient. The change in speed and direction over a set change in position of the observer.
Climatic elements include precipitation, temperature, humidity, sunshine and wind velocity and phenomena such as fog, frost, and hail storms.
The RDA collects the unprocessed, analog voltages from the radar antenna and converts the signal to base reflectivity , base velocity, and spectrum width (in polar coordinate form).
per KilogramGageIn hydrologic terms,
1) A device for indicating the magnitude or position of a thing in specific units, when such magnitude or position undergoes change, for example: The elevation of a water surface, the velocity of flowing ...
Storm Relative Mean Radial Velocity Map(SRM): This WSR-88D radar product depicts a full 360º sweep of radial velocity data with the average motion of all identified storms subtracted out. It is available for every elevation angle sampled.
It operates on the principle that the propagation velocity of a sound wave in a moving medium is equal to the velocity of sound with respect to the medium plus the velocity of the medium.
The thalweg is the part that has the maximum velocity and causes cutbanks and channel migration.
When used in reference to Doppler radar, it describes the change in radial velocity over short distances horizontally. SHEAR LINE A line of maximum horizontal wind shear.
general circulation models Hydrodynamic models of the atmosphere on a grid or spectral resolution that determine the surface pressure and the vertical distributions of velocity, temperature, density, ...
"Doppler" radar is a special type of radar that makes use of the Doppler Effect to measure not only the distance of a target, but its velocity as well.
The effect of the velocity of fluid flow upon the velocity (relative to a fixed external point) of an object moving within the fluid; ...
QG Forcing- Upward vertical velocity generated by low level convergence or upper level divergence.
1st Law: Defines the Law of Force: A body remains at rest or moves with constant velocity in a straight line unless acted upon by a force. 2nd. Law: Defines Mass: The amount of force necessary to accelerate a body depends on the mass of the body.
The method is emperical and considers a number of parameters (ingredients) which cause snowfall, including vertical velocity (upward lift which carries air aloft to a condensation level) and mixing ratio (the mass of water vapor per mass of dry air ...
Wind shear: the rate at which wind velocity changes from point to point in a given direction (as, vertically).
KNOT A nautical unit of speed equal to the velocity at which one nautical mile is traveled in one hour. Used primarily by marine interests and in weather observations. A knot is equivalent to 1.151 statute miles per hour or 1.
Radar that can measure radial velocity, the instantaneous component of motion parallel to the radar beam (i.e., toward or away from the radar antenna).
It is described as a sudden increase in wind velocity in tropical and sub-tropical waters, and lacks the usual dark, ominous squall clouds. The white squall may be myth, or it may be a microburst.
of reference, the 'storm relative' helicity, [ Hr ] between the surface and a height, [ h ] and is calculated as an integral between those limits thus: (Vh - C) x Wh x dh [units=m**2/s**2 ] Where [ Vh ] is the environmental horizontal wind velocity , ...
Knot: a measure of speed equal to the velocity of one nautical mile traveled in one hour. Usually used in marine studies. One knot equals 1.151 miles per hour or 1.852 kilometers per hour.
Surface Wind: By convention, the term applies to wind velocity at 10 meters height and in unobstructed areas.
Surge: Violent breaking of the waves in the coast, caused by rough seas.
Law of Conservation of Angular Momentum - The product of the velocity of an object around a center of rotation (axis) and the distance of the object from the axis is constant.
Using the Doppler effect, it measures the velocity of particles. Named for J.
Coriolis force (deflecting force) Apparent force, due to the rotation of the Earth, which acts normal to, and to the right of the velocity of a moving particle in the Northern Hemisphere, ...
The component of the velocity vector along the local vertical.
Wind Chill ...
An object (or parcel of air) in circular motion is constantly accelerating (changing its velocity) and the centripital force is the force which causes this acceleration. It acts towards the centre of rotation of the motion.
TVS - Tornadic Vortex Signature. Doppler radar signature in the radial velocity field indicating intense, concentrated rotation - more so than a mesocyclone.
Twister - A colloquial term for a tornado.
VENTURI EFFECT - The physical property of a fluid where its pressure is decreased as a result in an increase in its velocity. Any surface which alters the flow of air creates a venturi effect to some degree.
DOPPLER RADAR: A type of weather radar which displays atmospheric motion. It utilizes the Doppler Effect to measure the velocity of particles in the atmosphere.
A system consisting of 25 satellites in 6 orbital planes at 20,000 km altitude with 12 hr periods, used to provide highly precise position, velocity and time information to users anywhere on Earth or in its neighborhood at any time.
DOPPLER RADAR: A type of weather radar that determines whether atmospheric motion is toward or away from the radar. It uses the Doppler effect to measure the velocity of particles suspended in the atmosphere.
and/or direction (directional shear) over a short distance within the atmosphere. Shear usually refers to vertical wind shear, i.e., the change in wind with height, but the term also is used in Doppler radar to describe changes in radial velocity ...
 See also: Surface, Temperature, Pressure, Air, Water
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