Instruments Used in Predicting Tornadoes

Nearly 850 tornadoes strike the United States every year. Because of these deadly storms, the National Weather Service has studied them since 1953 in an attempt to predict potential twisters. Today, there are several instruments used in predicting tornadoes. Doppler radar, Lightning Imaging Sensor, Multiple Antenna Profiler Radar, infrasound detectors and hand-drawn analyses are all used as a means to forecast potential tornadoes.

Doppler Radar

• Though the Doppler radar is effective in alerting meteorologists to a storm front that is producing heavy winds in a circular pattern, tornado spotters are still needed in order to confirm that a twister exists. The radar's beam, which forces microwaves into the precipitation and creates an image of the wind's motion, is too wide to properly pinpoint the actual tornado. Therefore, the Doppler radar can only suggest that conditions are ripe for a cyclone to present itself.

Lightning Imaging Sensor

• In the 1990s NASA developed a satellite known as a Lightning Imaging Sensor in order to calculate the number of upper atmosphere lightning strikes in a storm. These lightning strikes, invisible to the naked eye because of dense cloud cover, are thought to be early predictors of tornadic activity. As the lightening increases, the likelihood of a tornado increases.

Multiple Antenna Profiler Radar (MAPR)

• The MAPR is a modified 915 MHz wind profiler with the ability to make lightning-fast wind measurements. Created by the National Center for Atmospheric Research, the MAPR's antenna is continuously observing vertical wind speeds. This continuity in wind measurements allows the radar to pick up on significant wind shears that might be missed by Doppler radar.

Infrasound Detectors

• Tornadoes send out ultra long-wave, low-frequency sounds. These noises, below the range of human hearing, are known as infrasound. Infrasound detectors can signal the approach of a tornado just minutes before it occurs. Because infrasound waves travel thousands of miles without losing strength, an infrasound detector in New York can detect a tornado about to occur in Texas. Therefore, meteorologists only need a few detectors to cover the entire United States.

Hand-Drawn Analyses

• The human hand is one of most important instruments in predicting tornadoes. Studies of surface and upper air data, which are drawn on maps, help forecasters to see patterns in the storm that may indicate cyclonic weather. These drawings indicate warm and cold fronts, pressure troughs and temperature fluctuations.