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Tornado Weather Instruments

Technological advances such as radars and satellites have greatly enhanced the ability of meteorologists to predict tornadoes and the paths they will take. However, funnel clouds still form and develop into tornadoes very quickly and no technology, at this time, takes the place of knowing the weather patterns and conditions that produce tornadoes.

  1. Doppler Radar

    • Doppler radar allows meteorologists to monitor the location and intensity of storms. Using an antenna, sound waves are sent out into the air. The radio waves are bounced back by moisture in the air. The frequency of the returned signal is higher if the moisture is moving toward the antenna and lower if it is moving away. The frequency is also affected by the speed at which it is moving. By using a number of different antennae at various locations, meteorologists get a good idea of the direction a storm is moving and when it is likely to arrive at different locations.

    Infrasonic Detection

    • Anyone who has ever been near a tornado will tell you that they are very loud. Infra-sound is a range of frequencies below the detection level of human hearing. An infrasonic detector composed of a special filter and a number of radial arms is able to detect slight sounds caused by changes in air pressure and wind at up to 1,000 kilometers, or more than 600 miles. Because the storms that produce tornadoes produce very specific sounds, the infrasonic detectors pick up potential tornado activity at great distances and before a tornado descends from the sky.

    Antomometer and Barometer

    • Barometric pressure is, literally, the weight of the air. It is the weight or pressure of a column of air as measured from the surface of the ground, or water, below it. Barometric pressure is measured in weight per square inch using a device called a barometer. Changes in barometric pressure frequently indicate changes in weather and sudden or drastic changes signal storms. A barometer is frequently used in conjunction with an anemometer, which is a device that measures wind speed.

    Lightning Detectors

    • Lightning is caused by static electricity in the atmosphere. Warm, moist air moving rapidly through clouds generates ice and rain drops, and the friction generates static electricity. The faster the air is moving the more lightning is generated. NASA, using satellite imaging, observes lightning activity in the upper atmosphere at altitudes too great to be accurately observed from the ground. By having lightning detectors both in space and on the ground, an accurate picture of lightning activity is formed. A high level of lightning activity is a sign of very fast-moving air and tornado activity.

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