calm (0–2 kn)
	3–7 kn
	8–12 kn
	13–17 kn
	18–22 kn
	23–27 kn
	28–32 kn
	33–37 kn
	38–42 kn
	43–47 kn
	48–52 kn
	53–57 kn
	58–62 kn
	63–67 kn
	98–102 kn
	102–107 kn

Wind speed is the speed of movement of air relative to a fixed point on the Earth. Wind is a term applied when talking about the movement of air from one place to the next. Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links No higher resolution available. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... This article or section does not adequately cite its references or sources. ...

Wind speeds usually mean the movement of air in an outside environment, but the speed of movement of air inside is important in many areas, including weather forecasting, aircraft and maritime operations, building and civil engineering. High wind speeds can cause unpleasant side effects, and strong winds often have special names, including gales, hurricanes, and typhoons. See the Beaufort scale for a discussion of this. A gale is a wind of at least 28 knots, 32 MPH, or 51km/h; and up to 55 knots, 63 MPH, or 102km/h. ... This article is about weather phenomena. ... Cyclone Catarina, a rare South Atlantic tropical cyclone viewed from the International Space Station on March 26, 2004. ... ...

Measurement

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Wind speed may be measured by a variety of tools. The anemometer, consisting of a rotating vane, has been the most common method of measuring speeds close to the ground for hundreds of years. A pilot can fix their position relative to the ground by using on board instruments, then use this information to estimate the wind speed and direction over the time they have been flying. Such reports can be used to confirm wind speed forecasts. The development of accurate electronic navigation systems, including inertial navigation and GPS enable this calculation to be done automatically. Modern GPS and inertial systems often include a direct readout of the current windspeed and direction. Image File history File links Circle-question-red. ... An anemometer is a device for measuring the velocity or the pressure of the wind, and is one instrument used in a weather station. ... An inertial navigation system measures the position and altitude of a vehicle by measuring the accelerations and rotations applied to the systems inertial frame. ... Over fifty GPS satellites such as this NAVSTAR have been launched since 1978. ...

Speed and velocity

Technically, wind speed is given by

,

where u, v, and w are zonal, meridional, and vertical components of wind velocity. Except in unusual circumstances (e.g. in cumulus updrafts), the vertical component of the velocity is much smaller than the horizontal components. In geography, geophysics, and meteorology, zonal usually means along a latitude circle, i. ... Meridional is a geographic term that means along a north-south direction, or relative to a meridian (opposite: zonal, east-west). ... This article or section does not adequately cite its references or sources. ... The velocity of an object is its speed in a particular direction. ...

Use in aviation

In aviation, wind speed is used to convert between ground speed and true airspeed. Ground speed is the speed of an aircraft compared to the ground without factoring in the wind or other weather conditions. ... True airspeed (TAS) is the speed of an aircraft relative to the airmass in which it flies, i. ...

This relationship means that windspeed can be calculated by comparing airspeed (from pitot-based instruments) with ground speed (from a GPS, INS or similar). When the GPS is operating, some aircraft will display the windspeed symbol on their navigation displays. A Pitot tube is a measuring instrument used to measure fluid flow. ... Over fifty GPS satellites such as this NAVSTAR have been launched since 1978. ... The acronym INS can refer to: Immigration and Naturalization Service Indian Navy Ship Inelastic neutron scattering Inertial navigation system Insert Key of a keyboard Insurgency, a multi-player mod for Half-Life 2 International Network Services International News Service International Numbering System adopted by the Codex Alimentarius Commission Irish Naval...

Factors affecting wind speed

Wind speed is affected by a number of factors, operating on varying scales (from micro to macro scales). These include the pressure gradient, Rossby waves and jet streams and local weather conditions. There are also links to be found between wind speed and wind direction, notably with the pressure gradient and surfaces that the air is to be found over. Wind direction is the direction from which the wind is blowing. ...

Pressure gradient is a term to describe the difference in air pressure between two points in the atmosphere or on the surface of the Earth. It is vital to wind speed, because the greater the difference in pressure, the faster the wind flows (from the high to low pressure) to balance out the variation. The pressure gradient, when combined with the Coriolis Effect and friction, also influences wind direction In the inertial frame of reference (upper part of the picture), the black object moves in a straight line. ... Friction is the force that opposes the relative motion or tendency toward such motion of two surfaces in contact. ... Wind direction is the direction from which the wind is blowing. ...

Rossby waves are strong winds in the upper troposphere. These operate on a global scale and move from West to East (hence being known as Westerlies). The Rossby waves are themselves a different wind speed to what we experience in the lower troposphere. Rossby (or planetary) waves are large-scale motions in the ocean or atmosphere whose restoring force is the variation in Coriolis effect with latitude. ... Atmosphere diagram showing the mesosphere and other layers. ... The westerlies are the prevailing winds in the middle latitudes between 30 and 60 degrees latitude, blowing from the high pressure area in the horse latitudes towards the poles. ... Atmosphere diagram showing the mesosphere and other layers. ...

Local weather conditions play a key role in influencing wind speed, as the formation of hurricanes, monsoons or cyclones as freak weather conditions can drastically affect the velocity of the wind. This article is about weather phenomena. ... A monsoon is a periodic wind, especially in the Indian Ocean and southern Asia. ... This article is about the meteorological phenomenon. ...

Highest Speed

The highest surface windspeed ever officially recorded is 231 mph (372 k/h) during a gust at the Mount Washington Observatory on 12th April 1934, using a heated wire anemometer. The anemometer was later tested by the US National Weather Bureau and confirmed to be accurate. Mount Washington can refer to 15 mountains in the United States and to a ski area on Vancouver Island in British Columbia, Canada: And also to some towns: Mount Washington, Kentucky Mount Washington, Massachusetts Mount Washington neighborhood in Pittsburgh Mount Washington neighborhood in Cincinnati Mount Washington neighborhood in Baltimore Mount... An anemometer is a device for measuring the velocity or the pressure of the wind, and is one instrument used in a weather station. ... The National Weather Service (NWS) is one of the six scientific agencies that make up the National Oceanic and Atmospheric Administration (NOAA) of the United States government. ...

A higher windspeed recorded at 236 mph (380 k/h) during Typhoon Paka in 1997 in Guam was declared invalid because the instrument was damaged during the storm and could not later be checked for accuracy. ...

Windspeeds within certain atmospheric phenomena (such as tornados) may greatly exceed this value but have never been accurately measured. The figure of 316 mph (484 k/h) during the F5 tornado, Moore in Oklahoma is often quoted as the highest surface windspeed but was measured by Doppler radar (which is only able to provide an estimate) and was measured 100 feet (30m) above ground. A tornado in central Oklahoma. ... Doppler Effect Doppler radar uses the Doppler effect to measure the radial velocity of targets in the antennas directional beam. ...

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Wind speed