Storm chasing is generally defined as pursuing severe thunderstorms with the intent to witness, photograph or scientifically measure the intensity of the storms, with chasers frequently focusing on the development of tornadoes.
It was once the hobby of a select few meteorologists and tornado researchers, fueled by their curiosity and desire to witness the weather that was often the focus of their studies. Storm chasing also provided real-world applications for their forecasting.
Chuck Doswell, a noted researcher and professor from the University of Oklahoma, was one of these early chasers and talks about its value in his career.
"Storm chasing has made me a better meteorologist than I would have been without it."
But what was once a niche hobby among a few has grown exponentially into a mainstream recreational activity, complete with tour-company buses, reality TV shows and an annual convention called ChaserCon
"When I began chasing in the '90s, it wasn't uncommon to be on a storm and not see any other storm chasers," said veteran storm chaser and meteorologist JR Hehnly. "When you did see someone else, it was often someone you knew or had at least heard of."
The single event most responsible for taking storm chasing into the mainstream was the release of the movie "Twister" in 1996, dramatizing storm chasing (quite unrealistically
) and igniting widespread interest in the pursuit of storms.
But while "Twister" may be responsible for an explosion of interest in chasing tornadoes, advancements in technology have made it possible for the masses.
"In my college days, there were no smartphones, mobile apps or even reliable cellular networks out in the field. We had to rely on atlases, nowcasters (someone back home with access to a computer) and education/scientific knowledge to get into proper position," storm chaser Lance Maxwell said of chasing when he was a meteorology student at the University of Oklahoma in the early 2000s.
"Now, anyone with an iPhone and a radar app thinks they have everything necessary to chase," Maxwell said.
In addition to the ease of tracking the storm, with loads of weather data and GPS available, smartphones have made capturing the moment and sharing those dramatic images much easier.
"What used to be shared with others on a VHS tape, personal website or in print via StormTrack magazine is now shared instantaneously to the entire world on social media," Hehnly said.
Maxwell echoed those sentiments, adding, "the glorification of highlight reel video on the Web and TV has turned many locals into self-labeled field reporters."
Types of chasers
Storm chasers are an assorted lot, coming from a variety of fields and backgrounds.
Some plan storm-chasing vacations (chase-cations), living out a lifelong dream of seeing a tornado.
One such chaser is Tanguy Taffin, a truck driver from Paris, who traveled to the United States to go on one of the many storm chasing tours provided by private companies.
"It's my dream," Taffin said. "I've always been fascinated by the weather." Along with about a dozen others on the tour, he picked a great week in May 2016. They saw 15 tornadoes.
Others are adrenaline-seekers, in it for the thrill of the chase.
You will find photographers documenting the abundant beauty nature provides with the storms, as well as those trying to get the next viral video of a too-close encounter with a tornado.
Scientists also still chase these dangerous storms, trying to learn exactly what causes some storms to produce tornadoes while others do not.
The proliferation of storm chasers has created its own phenomenon, known as "chaser convergence." On a day with storms expected during the peak months of April, May and June, you can find several thousand chasers filling the Plains of the central United States, all chasing the same handful of thunderstorms.
Because most of these areas are rural, the increased traffic can create a nightmare on the crowded roads. Difficult driving conditions are created by stormy weather, and motorists can become distracted when they are searching the sky for tornadoes.
In March, three storm chasers died
as their two cars crashed into each other while they pursued a tornado in Spur, Texas.
Many fear that a bigger disaster is inevitable: a dangerous tornado bearing down on chasers while they are stuck in traffic on a rural farm road.
Hehnly recalled a storm near Kingfisher, Oklahoma, in May 2010. "Scores of storm chasers were heading east away from the storm, completely filling Highway 33."
Luckily the approaching storm weakened, but "if the storm had been producing a tornado at the time, it would have likely caught some storm chasers that were unable to flee due to the slow-moving traffic," Hehnly said.
Chaser convergence not only creates a dangerous situation for the chasers, it can prevent first responders from quickly accessing victims of the tornado.
I have witnessed ambulances unable to access roads because of the volume of traffic and cars not pulled completely to the side.
Chaser convergence also impedes the work of the scientists trying to deploy their instruments in and around the path of the storm.
Chris Weiss, a tornado researcher from Texas Tech University, told CNN of a recent encounter in May.
"Our research group was coming into position to make measurements on a developing tornado in the Texas Panhandle but could not find any locations to park the radar, as all available vantage points were occupied with chaser traffic," he said.
"I am not suggesting that one group has a right to be there over another, but if asked whether science has been impacted at some level over the past few years, I would say yes."
What can be done about chaser convergence?
Unfortunately, there is little that can be done to stem the tide of storm chasers and limit the problem of chaser convergence.
"People are free to travel in the US," Hehnly said. "One thing that might help is if local media could make it clear to viewers that they should not be going out to try to look at the storm."
Weiss added, "I have had various colleagues suggest some manner of barricading, checking of IDs, etc. to discourage recreational chasing. Obviously, these types of ideas place the burden on law enforcement, who are already severely taxed with responding to the threats posed by the storm to their communities."
Veteran storm chasers know there are some ways to avoid the biggest crowds.
Weekends and holidays bring out the largest numbers of amateur chasers, as well as predicted outbreaks such as "high-risk" days as designated by the National Oceanic and Atmospheric Administration's Storm Prediction Center
. Certain locations, such as central Oklahoma, are known for the prevalence of storm chasers.
Weiss takes chaser congestion into account when planning his team's chasing target.
"Central Oklahoma is pretty much a nonstarter for us at this point. The chaser density maximizes here, and even though this region represents the climatological peak in tornado occurrence, the congestion throws the risk-reward ratio out of balance in my mind."
As much as Weiss and other scientists try to avoid the throngs of chasers, their scientific vehicles are a beacon for the swarm of amateur chasers.
John Marr, who owns an excavating business and has chased storms as a hobby for three years, said he tries to stay out of the scientists' way but admits following them.
"They've got a hell of a lot more information and expertise; you cant go far wrong when you're following behind all those types of guys."
No matter the type of chaser -- experienced or rookie, meteorologist or amateur -- by practicing safe driving and respecting the power of the storms from a safe distance, one can limit the dangers associated with storm chasing. And for cutting chaser traffic, carpools are always an option.