How the Totable Tornado Observatory Worked

­T­he United States holds nearly exclusive geographic rights to tornadic activity. An unusual weather phenomenon known as a dryline can be fou­nd running latitudinally east of the Rocky Mountains through the Central Plains. It accounts for the infamous Tornado Alley that stretches from Texas to North Dakota and shoots off east toward Ohio. This dryline separates dry air from moist air, and when the two types of air mix, thunderstorms form along this boundary. These storms can spawn the freakishly high number of tornadoes the U.S. experiences each year, much more than any other region in the world sees. Japan, for example, experiences an average of 20.5 tornadoes each year, while India gets 0.5 annually [source: Weather Doctor]. Central Europe sees about 10 per year, and Canada hosts an average of 80 twisters annually [source: Max Planck Institute, CBC]. The United States, by contrast, gets hit with around 1,200 tornadoes every year [source: Washington Post].

Armed with this data, it shouldn't be much of a surprise that American meteorologists came up with the idea of a weather-measuring device that could be placed in the path of a tornado. In 1979, National Oceanic and Atmospheric Administration (NOAA) researchers Dr. Alan Bedard and Carl Ramzy constructed the TOtable Tornado Observatory (which the pair dubbed TOTO after Dorothy's dog in "The Wizard of Oz"). Two years later, it would be the first man-made weather-sensing apparatus deliberately placed in the path of an oncoming tornado.

TOTO was a fairly primitive piece of equipment by today's standards. Bedard and Ramzy used a 55-gallon metal drum as the shell that housed the sensitive weather equipment sealed within. This equipment consisted of an anemometer (a device that measures wind speed with a spoked series of arms or cups perched atop a pole), thermometer, atmospheric pressure gauge and dew point sensor [source: NOAA]. The data collected from all of these instruments was recorded, which could be retrieved and analyzed later [source: Tornado Project].

Meteorologists compiled the data of the climactic conditions found around and inside tornadoes into computer models. These models could in turn be used to analyze supercell thunderstorms when they developed to determine if the conditions needed to produce tornadic activity were present. The information produced by TOTO could help meteorologists better understand tornadoes, enabling them to issue early warnings to the public and hopefully save lives.

All told, TOTO weighed 400 pounds (181 k) [source: PBS]. Such a bulky package required a customized pick-up truck to transport it. When ferried out to a site, TOTO could be rolled down a ramp and hoisted upright into place in about 30 seconds. Since TOTO predated global positioning satellite (GPS) navigation, the handlers had to use a compass to orient markings on the barrel toward true north to serve as a baseline for measurements. After that, TOTO was ready for action. All it needed was a tornado to measure.

­TOTO got its chance on a couple of occasions. But what works in theory doesn't always work in practice. Find out why TOTO didn't work in the field on the next page.

Today, people who chase and study storms professionally or for fun use the Internet and laptop computers to track them. Before the advent of on-demand, real-time information, storm chasing was much more of a guessing game. Anyone who wanted to put, say, a 55-gallon drum filled with highly sensitive meteorological equipment in the path of a tornado was forced to use minutes-old information broadcast by weather stations and the local media on the radio. A storm chaser also had to use a little intuition and his or her experience of seeing storms firsthand to predict which storm cell might produce a tornado and which might not.

This was one of two main problems inherent in TOTO that became evident in the field. Putting TOTO directly in the path of an oncoming tornado required an astronomical amount of luck; the probability of perfect placement was decidedly low. The other problem TOTO presented was the danger it posed. Unloading and setting up TOTO may have taken a mere 30 seconds, but that can be a long time when a twister is bearing down on you -- that's 30 seconds less the researchers had to escape. And despite TOTO's 400 pounds (181 k), a tornado could conceivably take the device along for a ride, transforming TOTO from a benign tool of science into a flying barrel of death. (Larger things have been swept up by twisters. In May 1949 in Oklahoma, 13 head of cattle were carried off by a tornado [source: Tornado Project].)

­All of these concerns were theoretical until TOTO was deployed into service across the Central Plains in the spring of 1981. Then concerns were confirmed. TOTO's engineers, Bedard and Ramzy, handed their creation over to Dr. Howard Bluestein, a professor of meteorology at the University of Oklahoma. From April to June of each year from 1981 to 1983, Bluestein and some of his students chased storms and placed TOTO where they thought a tornado was likeliest to pass [source: PBS].

Bluestein confirmed both the danger posed by and improbability of the success of TOTO. He never successfully placed it in a spot close enough to gather data from a tornado. And he saw firsthand how dangerous TOTO could be. During one storm chase in 1982, Bluestein and his team had a close brush with a tornado they were attempting to get in front of to place the device in its path [source: PBS]. After 1983, he turned TOTO over to the National Severe Storm Laboratory, a research laboratory affiliated with the National Oceanic and Atmospheric Administration (NOAA). The NSSL was the only group to ever successfully place TOTO in the path of an oncoming twister.

On April 29, 1985, NSSL researchers Steve Smith and Lou Wicker picked the right place to situate TOTO, outside of Ardmore, Ark. A feeble tornado brushed past the device, revealing another defect of TOTO's concept and design: It had a high center of gravity. As the tornado passed, TOTO was knocked onto its side, damaging the instruments. After its closest brush with fulfilling its original purpose, TOTO was deployed unsuccessfully for two more years.

­TOTO was retired from service in 1987. It's on display in the lobby of the National Weather Service in Norman, Okla., greeting visitors [source: NOAA]. But TOTO left behind an unfulfilled need to gather valuable data about tornadoes by taking them head-on. In that regard, TOTO left a legacy. Read the next page to learn about TOTO's descendants.

About the time that TOTO's deployment was winding down, other technologies that built upon TOTO's concept were gearing up. The first technology to take over the hazardous duty of being placed in the path of an oncoming twister was the turtle. These small, round devices look like hubcaps and were first sent into the field in 1986 [source: Tornado Project]. Instrumentation similar to that installed in TOTO was tucked inside turtles to record atmospheric pressure, humidity and temperature. What's more, the turtle made the jump to digital, allowing smaller instruments to produce more accurate readings.

Since turtles are small, they can be deployed throughout an area, increasing the chances one may be passed over by a twister. In May 1988, a turtle was impacted by a tornado in Oklahoma, but by the time the researchers retrieved it, the device had been tampered with, ostensibly by a curious human [source: Tornado Project].

Other devices also followed in the footsteps of TOTO. Dillocams and OZ (Observation Zero) were both designed to be placed in the path of a tornado. Both are outfitted with video cameras to capture visible data of the conditions within a twister. Snails, similar in appearance to turtles, are outfitted with seismic sensors to determine if tornadoes produce vibrations that can be felt in the ground when they pass. Researchers hoped an early warning system could be produced using seismic sensors already in use for earthquake detection, a system that's still in development [source: MSFC].

All of these devices, like TOTO, have a failing, however. Each is a one-shot deal. The optimal tornado measuring equipment would be a marriage of TOTO's portability a weather bureau's sophisticated instruments.

With the advent of Doppler radar, this became possible. Doppler radar uses radio waves to determine the density, direction and precipitation of a storm. A storm moving toward the radar sends back higher frequency radio waves to the antennae that originates and accepts waves. A storm moving away from an antenna returns in lower frequency [source: USA Today]. Doppler radar can pick up such large amounts of information about a storm that this data can be rendered into a 3-D representation of it. Meteorologists can now look into a storm to examine its characteristics, such as if it's producing hail or possesses a mesocyclone.

The Doppler On Wheels (DOW) project from the Center for Severe Weather Research and the Electra Doppler Radar (ELDORA) project from the National Center for Atmospheric Research were the first to take Doppler on the go. DOW is a Doppler antenna mounted the back of trucks, and ELDORA is a prop plane outfitted with an antenna. Both were used in the VORTEX project, arguably the first mobile tornado project to produce significant data. In June 1995, VORTEX tracked storms in Texas by plane and truck, compiling data from above and around the storm and providing meteorologists new raw information to be used for predicting when and where tornadoes will occur [source: UCAR].

While TOTO may have never taken a single accurate measurement of a tornado, the one-of-a-kind device helped pave the way to a thorough understanding of tornadoes, those steeples of fire in the sky.

For more information on tornadoes and other related topics, visit the next page.

I don't remember how I landed the assignment to write about the Totable Tornado Observatory. I do recall that it sank in very quickly, after just a little bit of preliminary research, that I had seen something like an ode to it in the movie "Twister." I thought it was an interesting homage and gave the movie a bit more weight. In fairly short order, though, I came to like the real story of TOTO more.

The haphazard, kitchen-sink-inclusive design of the TOTO that these highly trained meteorologists had to come up with themselves was almost comical. This thing could use a pressure gauge, I could imagine one meteorologist saying. "Well, put one in there," I could hear another replying. And the name, itself an homage to "The Wizard of Oz," really illuminated the blurred line between hobbyist and scientist among the storm chasing community, which I came to respect.

And I also remember coming to the realization that TOTO's creators came to at some point: How are they going to get the observatory precisely in the path of a tornado? This one turned out to be really interesting and fun to write.

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