The second and final season of storm chasing for Vortex2 — the largest and most ambitious scientific tornado research project ever attempted — was almost exactly the opposite of last year.
That proved both fruitful and frustrating, officials said.
Where 2009 was so quiet the team was only able to gather data on a single tornado, this year was so busy the armada couldn't keep up with all of the twisters.
But last year's single tornado was a behemoth — something the Vortex2 team never did catch this season.
"We only had a couple of opportunities" to document large tornadoes, said Lou Wicker, a research scientist with the National Severe Storms Laboratory.
In each case, he said, they were unable to catch them.
"When they're moving 50 mph, they're almost impossible to document," Wicker said. "You can't keep up with them."
Vortex2 spent six weeks in the field documenting tornadoes, wrapping up June 17.
About 100 researchers, more than 50 vehicles, about 10 mobile radars — and, for the first time, an airplane — were part of the armada.
"We encountered quite a number of smaller, short-lived tornadoes this year," 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, we only got one, but the one we got was a very good one — a significant tornado. We got all parts of our armada on it. Every element, every part of the experiment got data.
"The ones this year were smaller, and many of them were fast-moving. It was much more difficult to get the data and get everyone on each event."
The unmanned airplane was deployed three times, collecting "really good data" on a strong thunderstorm June 10 in Colorado, Burgess said.
The plane gathered data on a strong rear-flank downdraft, which researchers think plays a key role in the development and sustainment of tornadoes.
Vortex2 researchers gathered data on at least 20 tornadoes, and as many as three of them may have been as strong as EF2 — meaning winds of at least 110 miles an hour.
But officials say it will be a while before they realize what that data contains.
"We'll be looking at this data for five to 10 years," Wicker said. "Two years from now, we're going to have a much better feel for what we're going to learn out of this."
Among the storm aspects they'll be studying is what triggers tornadoes.
"There's undoubtedly more than one way to form a tornado because not all of these tornado genesis events looked the same," Burgess said.
While every chase season has "close calls" with tornadoes, Burgess said, a Vortex2 radar nearly got nailed in early June.
The crew was tracking a tornado just east of Scott's Bluff, Neb., on June 7 when it changed course.
"We had to stop and let it go in front of us," Burgess said. "It got fairly close."
So close, he said, "We were just out of the debris cloud."
Vortex team members were frustrated that a significant tornado event occurred just two days after their project had ended.
But it's hard to be too disappointed with this year's field research, Burgess said.
"I'd have to say we're pretty satisfied to get as much data as we hoped to get, and then some," he said.
"It will give us plenty to look at."