New Radar Aims to Improve 75 percent False Alarm Rate on Tornadoes

CHICKASHA, Okla. (AP) _ An experimental radar system aimed at giving meteorologists a clearer picture of a forming tornado is being installed in Chickasha, Rush Springs, Lawton and Cyril, according to a University of Oklahoma meteorology professor.

Dr. Kelvin Droegemeier says the system is expected to go online by next spring.

The radar system is being developed jointly by the University of Oklahoma and three other universities. It is called the Collaborative Adaptive Sensing of the Atmosphere program, said Droegemeier, who also is director of the Center for Analysis and Prediction of Storms.

The radars in the four communities will form a diamond-shaped test bed.

Droegemeier said the system is designed to fill in the current blind spot in NEXRAD radar which is caused by the curvature of the earth.

Because of that, NEXRAD can only see above three kilometers to the top of a storm.

By using a network of low-powered radars in close proximity, the CASA program radar is expected to be able to bring the scanning range down to within 50 meters of the ground. The radar also will be able to target specific weather features, including tornadoes that are shrouded in heavy rain.

Droegemeier said that once developed, the low-powered radars could be installed on cell phone towers across the country to provide a large overlapping network of weather radar.

He said the test area was picked because it sees an average of 50 severe storms per year with an average of two tornado touch downs a year. The storms also create about four false alarms per year.

Droegemeier said 75 percent of the current tornado warnings are false alarms because of how NEXRAD reads a storm.

The system should be able to identify a tornado within 60 seconds of formation and provide meteorologists with street-level tracking of weather events.

The system is part of a $40 million research project, announced last year, that is aimed at increasing the warning time for not only tornadoes but also flash floods and other severe weather disturbances.

The main office of the research center is at the University of Massachusetts Amherst. However, OU is a primary research partner in the center's weather and early warning projects.

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