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.
To augment, and possibly replace, the nation's current weather radar system, McLaughlin wants to mount small antennas on top of existing cell phone towers, home roofs and other structures.
Each new radar antenna would scan 30 kilometers (18.6 miles) using only a few watts of electricity in a couple minutes.
The scientists also plan to overlap the radar, improving resolution more than 125 times and letting meteorologists get a better idea of what is happening inside a storm.
McLaughlin estimates it would take about 10,000 of the new antennas to cover the entire nation, although 2,000 radars, spread in a semi-circle to the west (storms generally travel west to east) of urban areas, would cover most of the U.S. population.
Currently the CASA group has one diamond-shaped test plot in Oklahoma covering about 7,000 square kilometers (2,700 square miles). Other sites are planned in Texas and Puerto Rico. A fully operational, nation-wide CASA system could be in place in 15 years.
According to Harold Brooks, a scientist from the National Oceanic and Atmospheric Administration, who is not involved in the CASA project, CASA has already seen several "interesting" storms and is generating lots of data for meteorologists to pour over.
The problem lies in translating those huge amounts of data into information that people in the path of the storm can use.
"Do I die here or do I die in the next room is not much of a choice," said Brooks. "We want people to be able to respond better than that."
Related Links:
Eric Bland's blog: Interior Design
Collaborative Adaptive Sensing of the Atmosphere (CASA)
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