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I'm curious to know where commercial weather services like the Weather Channel and Weather Underground get their wind speed and direction measurements, to produce maps like this one (http://www.wunderground.com/maps/us/WindSpeed.html?MR=1):

enter image description here

A model is probably used, but how does the station measure or acquire real measurements to assimilate the data into the model? Is it by regularly placed anemometers on the ground? Or data measured by satellites?

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Weather stations and airports around the world almost always include an anemometer. Because of ground friction, the wind speed varies with height, so instrumental deployment is set at a standard height of 10 metres in open rural areas. This may require some adjustment in urban or forested areas. In fact, measuring accurate wind speeds above tree canopies is particularly difficult. There is quite an art in correctly positioning the instrumentation. Thousands of such anemometers and direction sensors are deployed on nearly every continent, and the results are part of the routine reporting. Such reporting may be every 24, 12, or 6 hours, or even shorter periods down to and including 'continuous'. Then comes the number crunching, in which the strength and direction is gridded and plotted on what appears to be a uniform distribution of points. In reality it is very far from a uniform distribution.

With the introduction of increasing numbers of wind farms higher elevation wind measurements are becoming more important.

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  • $\begingroup$ In addition to anemometers, isn't wind speed also measured using Doppler radar? $\endgroup$ – njuffa Jan 21 '16 at 23:17
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    $\begingroup$ @njuffa, I thought I'd heard ECMWF was starting to experiment with such, but couldn't find any evidence. But it'd be real tough. Yes, Doppler measures winds. But it cannot guarantee direction without a second radar. Things like range folding make it laborious to determine wind vectors from Doppler. Additionally, radar measures at increasing heights from the radar station (100s of meters at most ranges [part of why we cannot clearly know when a tornado touches down from radar]). Plus atmospheric complexities like beam ducting and hail spikes further complicate mapping the wind value's location. $\endgroup$ – JeopardyTempest May 23 '17 at 7:50

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