Web edition: July 13, 2012
Print edition: July 28, 2012; Vol.182 #2 (p. 32)
When Tim Samaras and his crew show up in a small town, their cars bristling with anemometers and other weather instruments, the welcome isn’t always warm. “There are locals who think we are bringing the weather,” says Samaras, 54. “One or two have even asked us to leave.”
True, it seems like wherever Samaras ventures each spring, tornadoes follow. But that’s just a sign of the storm chaser’s knack for staying a step ahead of his prey. “We cannot go to Google and order up a tornado,” he says. “We have to go find it ourselves.”
This year during peak tornado season, Samaras and his colleagues spent March through June chasing twisters across the Midwest, zigzagging up to 1,000 miles a day. The chase is a labor of love for the engineer, who works independently and recruits outside funding to help pay for his seasonal occupation.
He began chasing storms as a child, bicycling after thunderheads as they blew eastward from his Colorado home. Today, Samaras doesn’t so much chase as get ahead of as many tornadoes as possible. When he can, he drops a steel-encased probe of his own design right in the tornado’s path. While he flees, the squat, conical probe rides out the storm, its shape designed to use the wind to keep it pinned in place. The probe records the pressure, humidity, temperature, wind speed and direction within the swirling core. Those measurements give Samaras rare insight into ground-level tornado dynamics — right where twisters wreak their havoc. Crucially, it’s also a region unseen by ground-based radar.
“The only way you can measure how powerful and chaotic those winds are is with in situ instruments,” Samaras says. “That is the piece of the puzzle I bring to the scientific table.” His probes once measured howling 100-mile-per-hour winds (160 kilometers per hour) at ankle height as well as a record-setting 100-millibar drop in atmospheric pressure.
Direct hits are few and far between, though. Even though 1,200 tornadoes lash the United States each year, Samaras has so far directly measured the vortices of just 12. “If you don’t get out in the field and chase a lot of mediocre opportunities, you have an excellent chance of not seeing anything,” he says. —Andrew Bridges
In June 2003 one of Tim Samaras’ probes was the first ever to capture video (shown) from inside a tornado. Samaras came within about 100 meters of this twister in Manchester, S.D., to deploy the instrument. Seven cameras inside the probe watched the oncoming twister from all angles.
Credit: T. Samaras