Tornado Technology on the Forefront of Forecasting
Posted May 1, 1998 7:00 a.m. EDT
RALEIGH — Extra minutes of warning can mean the difference between life and death. NC State meteorologists and the National Weather Service are working to identify differences between tornadoes in the great plains of the midwest and southeastern tornadoes.
There are definite differences, but research until now has been done in the Midwest. Storm chasers see a huge, spiraling cloud over flat land in the plains. The severe storm is called a "super cell," and from it tornadoes spawn. Tornadoes come from different weather patterns in the southeast.
We have mini super cells," explains Professor Steve Koch of NC State. "They're shallower. They're smaller in diameter than super cell storms in the southern plains."
Tornadoes here are severe and harder to spot by meteorologists. Features of storms in this area are harder to spot on Doppler radar partially because the way radar works. Research by NC State graduate student Chris Vandersip shows southeast tornadoes form closer to the ground,
"You don't get to see as much, and you might not see it as soon as you would like before say a tornado hit or severe weather," Vandersip says.
Vandersip compared 81 tornadoes from the plains and the southeast like those in South Carolina. It is hoped the new research will lead to quicker and more accurate warnings.
"(We) look for different features in the mid and upper levels of the atmosphere that might give us signs," says Steve Harned of the National Weather Service. "'Hey, this one is trouble,' while we maybe can just monitor the one 30 miles away."
Researchers are also working with new forecast computer models that will help forecasters detect the presence of cold fronts at higher altitudes. This type of front can trigger lines of tornadoes and severe thunderstorms. Forecasters from across the southeast will gather in Raleigh in August to be trained in the use of these new technologies.
The Midwest may be home to tornado alley, but the South is twister death row. From 1950 to 1997, "tornado alley" states saw about 13,000 tornadoes, and 1,100 tornado deaths.
In southeastern states, nearly 9,000 twisters touched down, killing 1,600 people. Mobile homes and geography may be partly to blame. Southeastern tornadoes often strike at night, catching people off guard.