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What: More than 100 scientists and 50 vehicles tracked supercell thunderstorms across 10 states. They spread across 30 miles or more of terrain at one time, gathering data on everything from solar energy to wind direction to raindrop size.
When: Spring 2009 and 2010.
Cost: $12 million, mostly from the National Science Foundation and National Oceanic and Atmospheric Administration.
Countries involved: U.S., Italy, Netherlands, United Kingdom, Germany, Canada and Australia.
States targeted: Nebraska, Iowa, Texas, Oklahoma, Kansas, South Dakota, Wyoming, Colorado, New Mexico, Missouri.
Total miles traveled: About 37,000, more than the distance around the Earth.
Storms chased in 2010: About 30 to 35 supercells, with data captured on about 24 tornadoes. In 2009, data was captured on three tornadoes, including a major one near the Wyoming-Nebraska border.
In Nebraska: Collected data on fast-moving, nearly 50 mph storms one day near Sutherland, Ogallala and Gothenburg and on another day, a weak tornado near Scottsbluff. Marginal storms near Hyannis and Broken Bow, but scientists were wowed by beauty of the Sand Hills (“super pretty, even if not supercell”).
Hotel rooms booked: About 8,000.
Sources: Center for Severe Weather Research, National Severe Storms Laboratory.
LAST CHANCE, Colo. — The swirling supercell thunderstorm fills the sky, a mother ship ready to spin out tornadoes, hail, wind and rain. Beneath it, a small army of tornado researchers fans out, deploying sophisticated but storm-battered weather sensors. The supercell is just what they need. They had been chasing this type of storm for 40 days over thousands of miles across the Great Plains.
Photo Showcase:On the road with Vortex 2
If successful, their research will lead to more accurate tornado warnings. If only they each can get to the storm. If only that was their sole problem. A June day chasing storms with leading tornado researchers underscores a basic law of science: Research is painstaking and frustrating. Roads don't lead to the storm. Equipment and vehicles break down. And the storm turns left when you turn right.
Clank. Clunk. Smack. Hail batters the van — another crack in the windshield.
Researchers Dan Dawson and Glen Romine drive up and down a short stretch of road in the Colorado High Plains.
Every six seconds, sensors on top of their van record temperature, humidity, wind direction and solar energy.
Meanwhile, a bulky gadget called a disdrometer sits on the side of the road measuring raindrop size and distribution.
More than 7,000 raindrops can pass through the gadget's laser beam during a minute of heavy rain.
“This is the fun part,” Romine says. “But it's the noninformative part. We won't know the result of this for a long time.”
The $12 million federal project, nicknamed VORTEX 2, is the most extensive tornado study ever.
More than 100 scientists and 50 vehicles traveled across 10 states, including Nebraska and Iowa, this spring and last. Fieldwork wrapped up in mid-June. Now the analysis begins.
Data from a smaller VORTEX study in the 1990s is one reason tornado warnings have become more accurate.
Data is the holy grail of tornado forecasting. Weather forecasts aren't based on cloud movement in satellite pictures or rain clusters in radar images.
Forecasts come from supercomputers that analyze hundreds of millions of data bits at 15.5 trillion calculations a second. Included are assumptions about what's happening. If scientists can capture data on what inside the storms spawns tornadoes, they can improve the assumptions in their computer models. That, in turn, should help meteorologists forecast whether an approaching storm is about to become the perfect storm.
Why measure raindrops?
Some unknown or series of unknowns within a storm triggers a tornado. Maybe it's a temperature change at the base of a cloud, differing air densities, conflicting winds, or all of these things.
Lots of tiny rain droplets cool the air faster than a few fat ones. It's the cool you get walking through a mist at an outdoor festival on a hot day.
Raindrops also create movement in the air. And they change the density of the air around them.
So maybe raindrops matter. Or maybe they don't.
* * *
This day had started out easy.
Researchers were tracking a supercell moving at 10 mph to 15 mph, slow enough that each team could deploy where assigned.
Dawson and Romine's job: Project where the storm will be in about an hour and a half, drive there, set up the disdrometer north of the circulation path with about five to 15 minutes to spare. Then drive back and forth near it, gathering data.
That first round of sampling data from the supercell was easy, despite the hail that cracked their windshield.
So afterward they packed up and headed toward the front of the storm, hoping to gather another round.
The rest of the day doesn't go so well.
Rain turns dirt roads into slop. The lack of roads complicates the chase.
Dawson struggles to keep the van on the road. Romine checks the storm's forecasted path on his laptop and maps a new route.
They target a site about 22 miles away, but it will take 40 miles along hilly, muddy roads to get there. And it's getting dark.
“Not a paved road within 40 miles,” Romine mutters.
They listen to radio chatter from other researchers.
The storm had dropped two tornadoes near Last Chance, in northeast Colorado. Other teams are taking in data, even though the tornadoes are not the major twisters they'd hoped for.
Romine and Dawson reach their target about five minutes too late.
Bad luck struck others, too. A leaky radiator. A flat tire. Malfunctioning mobile radar.
Weeks on the road take their toll.
What if the dream tornado picks this time to land, Dawson jokes.
“Oh yeah,” he says. “That was when we were stuck on those mud roads.”
Still, the storm fascinates.
The whole system is many miles wide, spinning like a top across the sky.
Churning for several hours, it spawned the two tornadoes and dropped baseball-sized hail — signs this supercell had amassed tremendous, sustainable energy.
“Regardless of whether it produces another tornado or not,” Romine says, “it's still a good storm.”
Contact the writer: 444-1102, nancy.gaarder@owh.com
Video:On the road with Vortex 2
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