Tornado-chaser offers advice for twister-phobes
This article first appeared in the St. Louis Beacon, Jan. 17, 2012 - As Tim Samaras and his buddies were driving down a county road during last spring's storms in the mid-South, a vicious tornado broke out of the nearby trees and tore across the road 200 yards away.
Just about anyone else would have been grateful to survive, but Samaras was disappointed: He didn't have more time to study the twister and toss instruments into its destructive path. "Our glimpse lasted about 10 seconds," he said.
In a dozen years of tornado-chasing, it was about as close Samaras' team has come to being hit -- other than a twister in 2010 that changed course about 17 seconds before it would have struck their vehicle. "I think I've set more instruments in the paths of tornados than anyone else on the planet," Samaras said in an interview with the Beacon.
As one of the nation's prime tornado-chasers -- often featured on the Discovery Channel's "Storm Chasers," which starts its sixth season next month -- Samaras came close to catching up with the multi-vortex twister that struck Joplin on May 22. It was one of the deadliest twisters in U.S. history, killing 162 and injuring more than 1,000 people.
"We were a bit south of Joplin, chasing a tornadic super-cell ... into the trees," recalled Samaras. "That tornado, especially as it was going through Joplin, was pretty much rain-wrapped," making it difficult to see in detail other than as a dark moving column.
Samaras and his TWISTEX team -- for Tactical Weather Instrumented Sampling in/near Tornadoes Experiment -- hunts tornados in the "tornado alley" region, including Missouri, from mid-April through the end of June. Logging 40,000 miles, they see between 30 and 70 tornados a year. And Samaras, an engineer based in Denver, sometimes gets so close that he can place instruments he designed into the twisters' paths -- measuring pressure drops within the funnel clouds.
The TWISTEX team wants to understand better how tornadoes form -- perhaps helping improve the lead time for tornado warnings -- and how tornadic winds damage structures. Samaras also wants to teach more people in America's tornado alley region -- by far the world's most active area for twisters -- how to prepare for them.
"The time to decide what to do is not when a tornado is bearing down on you, but well in advance -- coming up with a family plan," Samaras said. "Everybody head to the basement, if you have one, and get under a workbench or pool table. If you don't have a basement, look for a closet, a bathroom. Jump in the bathtub, pull a mattress over your head. Knowing what to do and being a little weather-savvy would save many lives."
In September, the National Weather Service -- finding that many Joplin residents had not paid enough attention to tornado warnings and prepared for the strike-- issued a report and pledged to take steps to improve disaster-warning communications to add a greater sense of urgency when a tornado nears.
Samaras said such warnings only work well if local people pay attention and have developed plans. "If you hear that a tornado watch has been issued for the area, it means conditions are very ripe for tornadoes," he said. "And a tornado warning means one is imminent. That's when you have to have a plan and know what to do."
In Joplin, he said, "The National Weather Service put out a tornado warning about 20 minutes before the tornado hit ... and the whole area was under a tornado watch for several hours. The issue is that not everybody knows what to do in the event of a tornado ... a lot of people try to outrun the tornado or to seek shelter when it is too late."
In the St. Louis area, old-timers have said that the sky tends to turn a greenish tinge when a tornado approaches and that a locomotive-like sound is a sure sign that one is near. But Samara said the greenish hue isn't necessarily predictive. "The green color just means a lot of precipitation in the clouds and refraction, probably due to hail," he said.
But a loud, train-like noise could be predictive in a city. "The train noise ... you hear when the tornado is in an inhabited area surrounded by buildings and trees and structure. The wind basically breaks through these buildings and creates a thundering noise," Samaras said. "In an open field, with no trees, it will sound like a very loud waterfall -- a loud rushing noise -- very different than a thundering noise."
While Samaras loves to chase twisters, he doesn't recommend that untrained chasers follow the same path. "The tendency is for kids to run out there with cameras and try to glimpse a tornado," he said. "But in a state like Missouri, if you're in a community, there will be trees and you won't be able to see much of anything. Also, that far east, chances are that the tornado will be rain-wrapped, as Joplin was."
Chasing Twisters for a Reason
Samaras has specialized in analyzing "energetic events" -- from tornadoes to bomb blasts. "I've done a lot of high-speed photography and blast work," he said.
"My passion has always been storm chasing, and about 10 years ago I developed an instrument to measure the pressure drop inside of a tornado" under grants from NOAA and other sources. Since 2002, he had measured pressure in more than 20 twisters.
"Measuring the pressure drop in front of a tornado gives us a real good idea of how powerful the tornado is," Samaras said. "It's slightly easier to measure the pressure drop than the wind speed inside a tornado."
The TWISTEX project includes four vehicles equipped with roof-mounted mobile mesonet weather stations. One of the vehicles carries the probes, which Samaras and fellow researchers try to toss into the path of tornadoes.
The main goals of the project are to improve the understanding of how tornadoes are generated, maintained and decay. That, in turn, may help experts better predict future tornadoes and also help engineers analyze exactly how tornadic winds damage structures -- and perhaps help improve building designs to lessen such damage.
"Measurements of the tornado itself, with in-situ probes or radar, are very rare," said Samaras. "They classify tornadoes basically by the damage they do." That's why Joplin was classified as an EF-5 -- the most destructive category of twisters.
"The measurements we take [of the tornado itself] mean more if we go in there and inspect the damage afterward," he said. "So we can compare the data we collect from the tornado to the actual damage that it does."
When a deadly series of tornadoes struck Tuscaloosa, Ala., and other parts of the south last April, the TWISTEX team saw several twisters develop. "It was a scary day for our team," he said. "There's nothing but trees and visibility is near zero," which gives them little warning when a tornado approaches.
Samaras said, "We watched the Tuscaloosa tornado form and then go right through the town. We saw several violent tornadoes that day."
Footage from last spring's twisters came too late to be included in the DVD issued this month by the Discovery Channel, Storm Chasers: Greatest Storms, which features Samaras and other experts recounting the most dangerous storms they have encountered.
But Samaras says the lessons learned in past storms apply to the tornadoes that struck Joplin and Tuscaloosa -- and the threat of twisters with "tornado alley," which stretches from the Great Plains down to Texas and eastward to Missouri.
"Tornado alley is the hottest spot on the planet for tornados. No other area in the world comes close," he said. "There are tornadoes in other countries, but tornado alley is ahead by an order of magnitude. Argentina may have 110 tornadoes in a year, while the U.S. has anywhere from 1,100 to 1,500 of them."
Why? Mainly because of the unusal confluence of weather patterns. "The region gets a lot of Gulf Stream moisture from the Gulf of Mexico and the desert southwest air moving east. And in the spring, you have a very active jet stream that fuels thunderstorms."