Instruments to Measure Wind Velocity

Measuring wind is an essential part of weather forecasting, and is especially instrumental in forecasting tropical storms and other severe weather, such as hurricanes and tornadoes. There are a few instruments that measure wind speed, velocity and direction.

The Beaufort Scale

• The Beaufort scale, invented by British Admiral Francis Beaufort in 1805, calculates wind speed in knots. The scale measures the force of the wind from 0 to 12, where 0 is considered calm (no wind) and 12 is considered a hurricane.

Anemometer

• An anemometer measures wind speed by spinning in windy conditions at the same speed as the wind. It has little cups that catch the wind, which is what makes them spin. A recording device counts how many times the cups spin within a set period of time.

Weather Vanes and Wind Socks

• Weather vanes are one of the oldest weather instruments in existence. They swing around in the wind to show wind speed and the direction from which it's blowing. Wind socks also measure wind speed and direction. The wind blows into the sock's open end and makes it point in the wind's direction. Wind strength can be estimated by observing how hard the sock flaps in the wind.

Doppler Radar

• The Doppler radar measures air velocity using the Doppler effect. The National Weather Service uses it most frequently to forecast weather and to track severe storms and tornadoes.