Improving Tornado WarningsMay 12, 1998
Think of the lives that could be spared if weather experts could predict more accurately the location of a tornado's development with enough time for people to safely move out of its path.
Research efforts are being made to do just that.
Dr. Don Greene, professor of geology and weekend meteorologist at KXXV-Channel 25 in Waco, has extensively researched the deadly tornado that struck the Central Texas town of Jarrell last year and confirms several factors that can help predict where a tornado may develop. Dr. Greene said that the combination of moisture content, lifting index and wind shear can possibly determine a tornado's location within a radius of a few counties hours before its development.
During the time of the Jarrell tornado, the highest area of moisture in the state was in Williamson County, where Jarrell is located. The highest lifting heat index occurred between Waco and Austin, and wind shear was highest between Austin and Brownsville.
These precursor elements were developed by Chuck Doswell, director of the National Severe Storms Lab at the University of Oklahoma. Dr. Greene has conducted primary research that supports these findings.
Typical tornado warnings cover 60 to 70 counties, but more specific warning areas could save more lives, Dr. Greene said. "Most National Weather Service watch boxes cover such a large area that they might not have meaning for people," he said. "We've learned from the Jarrell tornado that information was available that would have narrowed the most likely spot for a tornado to the Interstate 35 corridor from Waco to Austin."
He said research has not proven the three precursor elements will predict tornado occurrence with 100 percent accuracy, but he hopes the risk area will be reduced over the next few years.
Dr. Greene has been involved in the development of a geographic information system at Baylor called Geographic Resources Analysis Support System (GRASS) that the University took over last year for the United States Army Corp of Engineers. GRASS instrumentation would effectively map moisture, lifting index and wind sheer, he said.
Dr. Greene recently gave a talk on his research at the national meeting of the Association of American Geographers in Boston and the Texas Natural Conservation Commission in Austin. The local Cablevision weather channel aired his Boston talk throughout March and April.