Kevin Myatt is The Roanoke Times' weather columnist.

kevin.myatt
@roanoke.com
981-3341

Weather with Kevin Myatt

Recent columns

• We got graupel, but not on official record
• Moisture could get caught up in cold blast
• Forecast for Weather Journal: Partly print, with frequent Internet
• Column archive

Read the Weather Journal blog

• Sprinkles or flurries possible Tuesday, but maybe something bigger for the weekend?
• For now, it looks like a quiet, mostly mild week ahead for SW Virginia
• Coldest morning of winter so far likely across much of Southwest Virginia; Tuesday precipitation looking doubtful
• Weather Journal blog

#swvawx on Twitter

@KevinMyattWx

• Follow Kevin on Twitter at @KevinMyattWx

Mechanical engineer Frank Tatom worked with NASA on the effect atmospheric turbulence has on the exterior of the space shuttle.

Northern Alabama, where Tatom resides, has been affected by many killer tornadoes over the years.

So that got Tatom thinking: If atmospheric turbulence can cause vibrations on the outside of the shuttle, wouldn't a tornado produce similar vibrations when in contact with the ground?

Tatom researched the matter. He found several instances of people close to tornadoes feeling vibrations through their feet; one even felt it through his bottom as he was sitting. He found that seismometers in the central United States had picked up signals connected to tornadoes at least 22 times between 1927 and 2005.

He even found that a Saint Louis University professor in the 1920s had written a paper about tornadoes creating seismic signals.

So, with this research in mind, Tatom conceived a possible tornado warning system consisting of a network of small seismometers covering a locality. Surfsimple Technologies, a California-based company specializing in emergency warning systems, has fleshed out Tatom's concept and is attempting to market it to tornado-prone regions of the central and eastern United States.

The current National Weather Service warning system for tornadoes relies primarily on Doppler radar, which can detect rotation within thunderstorms, and visual sightings by spotters.

Doppler radar technology has increased the average lead time for tornado warnings to 15 minutes, and the public receives warning for about 73 percent of the tornadoes that occur, according to Joe Schaeffer, director of the Storm Prediction Center in Norman, Okla. But it's also true that a tornado occurs in only 26 out of every 100 warnings issued -- a false alarm rate of 74 percent, Schaeffer said.

So many false alarms don't help public confidence in warnings, Tatom said.

"When I hear a tornado warning, and I know it's a ways out, I know most of the time it's not going to actually occur," Tatom said. "I don't take cover immediately. Nobody likes to admit it's crying wolf, but to a lot people it is, and they don't take cover like they should."

Tatom says that his concept, called Seismic Detection of Tornadoes, can add an important layer in the tornado warning system. It's not intended to replace Doppler radar or spotters, he said, but can confirm whether or not rotation detected by radar is actually producing a tornado on the ground.

Prashant Mandal, chief executive of Surfsimple, said that the seismic detection method has added value at night, when tornadoes are not easily seen.

"As tornadoes have been landing more and more [in the] last few years, we've thought 'There has got to be a method of detecting these tornadoes,' " Mandal said. "They really don't have much warning in the middle of nighttime. This is a mechanism that allows us to detect these tornadoes."

Tatom said the seismic network can act like a "tornado observer that works 24 hours a day, day or night. It's not bothered by terrain or vegetation that might obscure the field of view. We're providing what amounts to a network of observers that works 24 hours a day at no pay."

But Schaeffer, whose office is charged with forecasting risk zones for tornadoes and severe thunderstorms nationwide up to eight days in advance, is not yet entirely sold on the seismic system.

Much more research is needed, he said. The problem, Schaeffer said, is that not all tornadoes produce seismic signals, and not all seismic signals unrelated to earthquakes are tornadoes.

"Frank really needs more study, and the problem is that in any location, tornadoes are so rare, they're few and far between," said Schaeffer, who has partnered with Tatom in research on the effects of El Nino on severe weather. "He needs to come up with definitive statistics that prove that seismic activity does exist with all tornadoes or a vast majority of them."

But Tatom and Surfsimple are pressing forward based on the research and development that has been done.

Mandal, who is in constant contact with emergency managers across the country, says localities from New Mexico to North Carolina have expressed interest in the seismic tornado detection system, but none has been able to come up with the money yet to install it.

"As the technology improves, if it saves lives, the government will see a lot more value in it," Mandal said.

A tornado-prone locality installing the system would offer an opportunity to collect data on whether it works.