Aging Weather Radar System Gets Makeover

June 26, 2008 -- Pressure is building over what to do about the nation's aging weather radar system.

A group of scientists, lead by University of Massachusetts-Amherst researcher David McLaughlin, plans to augment, or even replace, the nation's large NEXRAD (Next Generation Radar) radars with smaller versions to give more accurate forecasts, saving people and property.

"We're trying to build a better hazardous weather warning system," said David McLaughlin, director of the Collaborative Adaptive Sensing of the Atmosphere (CASA) program at the University of Massachusetts-Amherst.

The nation's current weather radar system of about 120 doppler radar stations was built in the early 1990s. It uses large, megawatt-powered antennas to scan hundreds of miles every five to six minutes.

The current system does an excellent job of monitoring weather in the middle and upper atmosphere. But weather patterns closer to the ground, where tornadoes and other severe weather occurs, are often missed because the Earth curves away from the antennas.

This creates blind spots in the current system that severe weather often slips through.

Four out of every five tornado warning are false alarms, says McLaughlin, and even with a "better safe than sorry" attitude, 20 percent of all tornados slip through the current network undetected.

"CASA is based on using lots of little radars to defeat the Earth's curvature problem," said McLaughlin.