Merger of storms helped form May 22 tornado
Sunday, July 24, 2011
JOPLIN, Mo. (AP) — Amanda Kent manages the Payless Shoe Store in Pittsburg, Kan., but on the weekend of May 22 she switched jobs to manage the Payless store at 1502 S. Range Line Road.
As she watched the weather turn for the worse that Sunday, she got a call from her husband, Jason Kent, who works for the Jasper County Sheriff’s Department.
“It’s 5:43 p.m. He calls me and tells me to take cover now — a tornado is coming your way. He’s heard this on his police radio,” she said.
She and a co-worker take cover under a three-sided desk in an office at the rear of the store. She thinks that a tornado, if one does come, will probably be small.
“I’m hoping it’s a skinny little thing that will shift away from us and miss us all together,” she said.
What this 29-year-old mother of one was not expecting was an EF-5 tornado with wind speeds of 205 mph that would be three-quarters of a mile wide.
Meteorologists at the National Weather Service forecast office in Springfield and at the Storm Prediction Center in Norman, Okla., also were thinking that, should a tornado form near Joplin, it would be small. Weather conditions that day did not favor the production of a massive tornado. Nothing in their crystal ball suggested that. If one did form, it might be an EF-2, maybe an EF-3.
But what happened that day in the skies west of Joplin was totally unexpected. Two storm cells, a large one from Southeast Kansas and a smaller one from Northeast Oklahoma, would merge and, in a matter of minutes, produce a monster.
“We grabbed some shipment boxes and scooted those in front of the desk we were under,” Kent said. “It wasn’t 10 seconds later that things started shaking, rattling and falling. This is what I thought would happen.”
What happened next is what she was not expecting.
“The desk was lifted up and the boxes were blown away. We were exposed on the ground a second or two. I was lifted into the air. My eyeglasses were blown off. I’m blind as a bat without them.
“I was then upside down in the air. I was swirling around. My feet were above my head and my ballet flats were flying off my feet,” she said. “It was a slow-motion deal. I was thinking: ‘Oh my shoes!’ It seemed like a long time, but it probably happened in two seconds.
“I’m thinking to myself and praying: ‘God, please don’t take me away.’ I lost my mom at 21. I have a son who is 1 1/2 years old. I’m thinking: ‘Don’t let my son not have a mother.’ It’s way too early for him. He would not even remember me.”
Kent, though pelted by debris and wood, survived. She pulled a piece of wood from her foot. She had another piece of wood pierce her side. Her right collarbone was fractured. Her co-worker, protected by debris that covered her, walked away with minor injuries.
Thirteen minutes after the phone call from her husband, Kent was in a pickup truck on her way to Freeman Hospital West. A teenage boy whose name she does not know stopped at the demolished store and gave her a ride. After receiving initial care at Freeman, she spent 19 days in recovery at Via Christi Hospital in Pittsburg. She is still being treated for the injury to her left foot.
Meteorologists still are trying to learn more about how a normal spring storm became a killer. They know storm mergers occurred about 15 minutes before the tornado developed and the mergers intensified the supercell that would produce the deadliest tornado since modern record keeping began in 1950.
They also know that observant radar operators in Springfield, without much evidence of a classic tornado hook on radar, detected rotation inside the storm and noticed the main storm appeared to be making a gradual right turn. These important observations proved crucial for the 24-minute advance warning that Joplin received.
But that’s about all they know. They cannot see into the storm to see exactly what happened.
“To get a tornado going is, in itself, a rare thing,” said Bill Davis, head meteorologist with the National Weather Service station in Springfield. “Now, just think about what it took to get that to happen with such a massive tornado.
“The mergers, if you will, added the steroids to this storm. We could have had an EF-2 or an EF-3 tornado without the merger. But something happened and it had to fit perfectly to produce this EF-5. The odds of that happening are astronomical.
“This is a tornado that was pieced together from several circulation mergers to make the perfect storm.”
For two days before May 22, computer modeling by the Storm Prediction Center suggested there was a 30 percent chance or slight risk of severe thunderstorms that day. It was not until May 22 that the forecast was upgraded to a moderate risk of severe weather. The tornado risk did not become elevated until later in the day when extreme amounts of low-level convection became apparent.
There were some early signs. The upper-level jet stream was farther south than where it should be for late May. At the surface, a frontal boundary was sagging into Missouri. The dry line in Oklahoma had shifted to the east. The stage was set for severe weather, but nothing about that day indicated what would unfold that afternoon.
“The forecast leading to the April 27 tornado outbreak across the Deep South and the forecast for Joplin on May 22 were fundamentally different,” said Greg Carbin, lead meteorologist at the Storm Prediction Center. “We knew a tornado outbreak would happen on April 27 with large, long-tracked and violent tornadoes. The forecast for Joplin was much more ambiguous. It was not considered an outbreak day.
“It was a typical day in May for widespread severe weather. This day in May in Joplin is what you would expect. Nothing really stood out.”
Bill Gallus, a professor of meteorology at Iowa State University who is studying the Joplin tornado, said, “I was at a recent gathering of meteorologists in Boulder (Colo.). Many of them said that the one bad thing about the Joplin tornado was that it was not like any other EF-5.
“What you had was a bunch of storms come together. It did not look like a classic storm that would produce an EF-5. With most EF-5s, you see them coming. This tornado was wrapped in rain. They did not recognize that it was a tornado until the roar was on them. Joplin did not see it coming.”
When the main supercell emerged on May 22 in Labette County, Kan., it headed east, but showed a tendency to turn right. As it got closer to Joplin, radar images showed a system that was falling apart. Then, other cells developed to the south, flanking the supercell.
One of the cells, which passed over Commerce, Okla., was on a collision course with the supercell.
Ernie Shelby, emergency management director at Commerce, saw it and recognized it for what it was — a dangerous storm.
“There was not an actual funnel sighted, but you could see the clouds rotating extremely fast up above the city. It was right over the police and fire station. We could see it turning in a circle right above us,” he said. “It wasn’t but a few minutes after that we heard that Joplin had been hit.”
Said Gallus: “Somehow those storms combined. We don’t know what went on in there. But it organized so quickly.”
Carbin said merging storms are not uncommon. When it does happen, it is more likely the storms will dissipate instead of becoming more powerful. But it does happen from time to time. The tornado that struck Pierce City in 2003 was formed when two storms came together. The tornado that struck Picher, Okla., in 2008 became more powerful when it joined another smaller tornado before entering Newton County.
“I would say that more than half the time these mergers cause destructive interference because it increases the disorganization of the storm,” said Carbin.
Kent, of Payless Cashways, is, like scientists, rethinking everything she thought she knew about tornadoes.
“I have lived my whole life in Missouri,” she said. “If there was a tornado warning, I would go to the basement where I felt safe. I was never overly worried and concerned.
“Never in my wildest dreams did I think something like this could happen. I did not know what a tornado could do,” she said. “My first tornado was an EF-5. That’s my benchmark now. It’s changed my whole impression of what a tornado is.”
Eric Wise, a meteorologist at the weather station in Springfield, issued his first tornado warning that day for an area north of Joplin at 5:09 p.m. when the newly formed cell joined with the supercell from Labette County. The city sounded its sirens at 5:11 p.m.
As Wise watched the radar, he detected upward rotation in the storm on radar. He also had heard about funnel sightings in Cherokee County, Kan. With no clear evidence of a classic tornado hook visible on radar, he issued a blanket warning at 5:17 p.m. for all of Joplin because it appeared the supercell was veering right. The city sounded its sirens again at 5:31 p.m. The tornado hit Joplin at approximately 5:41 p.m.