As we’ve seen in just the past year alone between the Oklahoma tornadoes and Hurricane Sandy, severe weather conditions can have dire consequences. Sandy was directly responsible for 72 US deaths and racked up $50 billion in damages (Porter). The tornadoes in Oklahoma this May were responsible for dozens of deaths and flattened entire towns. It is obvious that these storms are incredibly dangerous, and when severe weather condition warnings are issued, everyone potentially affected should take precautions and protect themselves – that is, everyone except for the few who grasp this opportunity to do the exact opposite and run after the danger.
The main reasons why people are willing to put themselves at incredible risk to chase storms are to understand extreme weather and document it. Hurricanes, for example, are relatively easy to map out and pinpoint because they develop over time rather than form from sudden storms. They can be easily observed by flying over the clouds or even into the storm itself while dropping weather instruments down into it and taking accurate measurements of the conditions.
Tornadoes, on the other hand, are of particular interest (and danger) to storm chasers due to their unpredictability and inaccessibility. Severe thunderstorms can build up enough energy to create, under the proper conditions, a cyclone of spinning air that can reach wind speeds of over 300 mph. Gigantic storm clouds that reach up to the stratosphere at an altitude of six miles, called supercells, contain massive quantities of air flowing upward. If the horizontal air movement within the supercell is also flowing in different directions, this, combined with the updraft which keeps the formation upright, creates a spinning effect called a mesocyclone. The energy within the storm fuels the cyclone, which becomes a destructive tornado if it touches the ground. To make circumstances worse, tornadoes are often accompanied by lightning, straight-line winds, heavy rain, and hail from the thunderstorms that started it all.
Tornadoes are formed most frequently in the late evening or at night after thunderstorms have picked up energy from the heat of the day. They can cause injury and death by picking up people and debris, hurling things through the air, crushing people beneath debris, and impaling people with objects flung through the air (Grabianowski). It is still unknown why some storms produce tornadoes while others don’t. It is also difficult to predict the path of a tornado because they can rapidly change direction. For these reasons, it’s critical to understand such storms better so that early warning systems can be more accurate and more effective.
The most basic equipment required for storm chasers involves documentation of the storm. Crews carry HD video cameras, often with multiple camera operators in order to capture several angles of a storm, as well as still, digital cameras, to capture images that might not appear as well on video. They also carry laptops in order to stay updated on changes in weather conditions, radios to keep in contact with each other when riding in several vehicles, and advanced, Doppler radar for visualizing the storm and associated meteorological features.
Radar, which is actually an acronym for “Radio Detection and Ranging,” was first developed by Heinrich Hertz in the late 19th century when he discovered that metal objects reflect radio waves. Later, in the mid-20th century, meteorologists took this principle and applied it to precipitation. Doppler radar transmits three to four times the number of microwaves per second that conventional radar does. By comparing the incoming reflected waves to the outgoing waves and observing the shifts in wavelength, meteorologists can visualize the storm. If the incoming waves are shorter than the outgoing waves, the storm is moving closer. If the incoming waves are longer, the storm is moving away. This process can be repeated by using multiple radar units, thereby creating a 3-dimensional image (Thurlow).
Because tornadoes form close to the ground, traditional Doppler radar tends to be insufficient – the proximity to ground makes it difficult to scan for meteorological phenomena since buildings and natural land formations act as obstructions blocking the outgoing and ingoing waves. Furthermore, since tornadoes form so quickly, in the timescale of seconds and minutes, the radar must also be able to rapidly survey the changing conditions. Advanced storm chasers require a “Doppler on Wheels” (DOW), a Doppler radar that is mounted on the back of a truck and is used to create radar weather maps. The DOWs that storm chasers use, though, transmit multiple radar beams at once and are able to collect data within 10 seconds (“The DOWs”), allowing the storm chasers to acquire immediate information about weather conditions and record on-the-spot information about tornado wind speed.
Some chasers also utilize a specialized Tornado Intercept Vehicle (TIV), a pickup truck that is heavily reinforced, weighs approximately eight tons, and can extend stabilizing jacks down to the ground, making it more difficult for a tornado to lift. The TIV also includes weather and communication equipment wired directly onto the dashboard and has windows that are specially designed to give cameras the best possible views of oncoming storms (Grabianowski).
While storm chasing is an important public service, it can be tedious – often once storm chasers are notified of potential tornado formations, they drive around for eight to twelve hours with no guarantee of seeing anything worthwhile, not exactly the most exciting task. And when storm chasers do find a storm, they can put themselves in grave danger, as was sadly evidenced in May when three veteran storm chasers were killed in the Oklahoma tornadoes. Tim Samaras, his son Paul Samaras, and his chase partner Carl Young were overtaken by a multiple-vortex tornado in the midst of a sharp, unexpected change in direction. This was the first time any scientific researchers were killed while chasing tornadoes (“Tim Samaras Dead”) and emphasizes just how dangerous these storms truly are.
Since there is still so much that is unknown about tornadoes, their formation, and their paths, it is important that storm chasers continue to make observations and collect data so that more accurate weather warnings can be issued, allowing people to react to tornadoes more quickly and more effectively and prepare themselves for potential danger.
Written by Constance Kaita
Image courtesy of raccoonvalleyradio.com out of central Iowa
“The DOWs.” CSWR.org. Center for Severe Weather Research. n.d. Web. 12 June 2013.
Grabianowski, Ed. “How Storm Chasers Work.” HowStuffWorks.com. How Stuff Works: Science. 29 April 2008. Web. 12 June 2013.
Peter, Carston. “South Dakota Tornado.” Photo. NationalGeographic.com. n.d. Web. 12 June 2013.
Porter, David. “Hurricane Sandy Was Second-Costliest in U.S. History, Report Shows.” huffingtonpost.com. The Huffington Post. 12 February 2013. Web. 12 June 2013.
“Tim Samaras Dead:Oklahoma Tornado Kills Storm Chaser, Son Paul Samaras, and Chase Partner Carl Young.” Weather.com. The Weather Channel. 4 June 2013. Web. 12 June 2013.
Thurlow, Dave. “Doppler Radar.” weathernotebook.org. The Weather Notebook. n.d. Web. 12 June 2013.