Vortex2 seeks deeper look inside twisters
07/18/2012 8:28 AM
07/18/2012 8:28 AM
This is one sequel that's all but guaranteed to be a better show than its predecessor.
Vortex2 — the largest tornado research project in history to explore how, when and why tornadoes form — hit the highways of Tornado Alley this past weekend for more than six weeks of twister hunting.
"In an average year, we'll get a number of opportunities" to document tornadoes, said Don Burgess, a retired federal research meteorologist who works part-time with the Cooperative Institute for Mesoscale Meteorological Studies in Norman, Okla. "Last year was extremely poor and limited."
So limited, in fact, that the Vortex2 armada gathered data on only one tornado — though it was a big one June 5 in Wyoming.
Officials hope to use data gleaned from Vortex2 to hone the ability to forecast tornadoes.
"The false alarm rate is too high," said Steve Cobb, the National Weather Service's liaison with Vortex2. "We really want to bring that down.
"We want to improve also the detection ability. The research that is going on here is really key for us to understand that."
About 100 researchers, more than 50 vehicles, about 10 mobile radars — and, for the first time, an airplane — are part of the armada.
The unmanned plane will fly into different sectors of the supercell thunderstorms to collect data. The plane has only been cleared to fly in airspace between I-70 and I-80, though, so opportunities for its use will be limited.
Unlike "hurricane hunters," which fly into the eye of a hurricane, this plane will be kept clear of a tornado's strongest winds, said Lou Wicker, a research meteorologist at the National Oceanic and Atmospheric Administration.
Scientists hope data collected by the plane will provide clues to the role rear-flank downdrafts, or RFDs, play in a supercell thunderstorm.
The RFD is a descending column of air that is warmer and moister than the surrounding atmosphere. It appears to promote rotation in a supercell thunderstorm — and, by extension, tornadoes.
"We think that might be very important in controlling when the tornado forms and how long it lasts," Wicker said.
Researchers will also pay close attention to the location of secondary gust fronts in relation to tornadic storms, since one last year with the Wyoming tornado appeared to help set up the conditions in which the tornado formed.
But researchers cautioned that Vortex2 isn't likely to come home with all the answers. In fact, they said, it'll likely generate more questions than answers.
"This kind of research is like peeling an onion," Burgess said. "There are many layers. Each time you peel back a layer, you think you've gotten to the center. But no, there's more layers....
"Every time we go out, we learn something new."
The Vortex2 armada turned heads everywhere it went last summer — both because of how large the contingent was and the sheer size of its vehicles.
Residents would take pictures of the long caravan, and parents would bring their children out to see the mobile radars and other equipment.
Other storm chasers often lingered near Vortex2's caravans, hoping they would be led to the storms most likely to produce tornadoes.
Wicker said he doesn't feel like a celebrity, but he likes the fact that Vortex2 turns heads.
"People are always curious, friendly and supportive," he said. "I am always grateful that people feel we are doing something important, and that they are interested in the weather and science, and that they are so interested that they grab their children and show them what we are up to."