published Thursday, October 27th, 2011

Experts: More killer tornado superstorms likely to strike Southeast

Ray Cardin stands in the spot where he survived the April 27 tornado huddled with his fiancee and dog in the center of their Rainsville, Ala., residence.
Ray Cardin stands in the spot where he survived the April 27 tornado huddled with his fiancee and dog in the center of their Rainsville, Ala., residence.
Photo by Dan Henry.
  • Six months after the storms
    For thousands of people across the Southeast, April 27 changed their lives. Forty-seven tornadoes tracked through our region, leaving 81 people dead. Times Free Press staff photographers traveled back to areas they visited after the storms to see the recovery six months later.

Some weather forecasters have suggested Tornado Alley, a swath through the Great Plains and Midwest that has seemed most prone to tornadoes, has shifted eastward to bring the killer tornadoes seen in the Chattanooga region this year.

But Greg Carbin, warning coordination meteorologist with the National Weather Service, says that is just too narrow a view.

Carbin says the alley really is a long L that for years has stretched into the Southeast.

But the tornadoes that mauled the Southeast six months ago were the super outbreak of all time.

Carbin said much more research is needed on the outbreak and the devastation it caused, but one thing is a pretty sure bet.

"It's likely to happen again," he said.

Blame it -- at least in part -- on a warming climate that will continue to evaporate more moisture off the ocean, prompting more extremes to impact the storms that already are bringing record floods and now possibly these record tornadoes to Tennessee, Georgia and Alabama.

David Gaffin, a senior forecaster for the National Weather Service in Morristown, Tenn., called the April 27 super tornado outbreak a subject of much future research.

"This was a very efficient event. It had 345 tornadoes -- more than double the previous record outbreak set in 1974," he told a symposium of weather experts a few months after the storms.

"Almost every storm was producing a tornado," he said. "It's the big event of our generation -- it's the big event of recorded history."

Now what?

Read the report "The Year of Living Dangerously."
Read the report "The Year of Living Dangerously."

Daniel Weiss, senior fellow and the director of climate strategy at the Center for American Progress, a Washington, D.C.-based think tank, fears there are more records in the offing.

"This raises the question, 'Is this the new normal?'" he said last week, touting new statistics from the Federal Emergency Management Agency.

So far in 2011, there have been 86 FEMA extreme weather disaster declarations.

It's the second such record set in consecutive years.

Until 2010, when FEMA had to declare 81 disasters, the agency's average number of disaster declarations over the past 60 years was 33.

"Scientists have predicted these are the kinds of extreme events that would occur as global warming increases," he said. "Is the extreme weather of 2010 and 2011 the beginning of that?"

Weiss points out that in 2010 Nashville had a 1,000-year flood and this year -- just on the heels of the tornadoes, Memphis had its second-worst flood on record.

"In fact we've had so many record floods that we're changing the definition of what a 100-year flood is," he said.

Officials with the U.S. Geological Survey say the term "100-year flood" is used in an attempt to simplify the definition of a flood that statistically has a 1 percent chance of occurring in any given year. It is often misinterpreted to mean a flood that occurs about every 100 years.

Changing patterns

The National Oceanic and Atmospheric Administration, the parent agency of the National Weather Service, has said that Earth's average temperature has risen by about 1.8 degrees in the past 100 years.

Weiss and scientists around the world say carbon pollution is causing a growing amount of heat in the earth's atmosphere, i.e., global warming. In turn, that warming is causing ocean temperatures to rise.

How can less than 2 degrees be so important?

Weiss, who just before the super tornado outbreak of all time helped write a report about 2010's extreme weather titled "The Year of Living Dangerously," said it's all about the oceans.

"It's the impact on the oceans that's driving a lot of the climate effects," Weiss said.

Earth's climate is both dynamic and fragile. As the oceans warm, they produce more water vapor, and when that happens there are more severe storms because there's more moisture in the atmosphere, he said.

"Because we have not brought carbon pollution under control, the weather events of 2010 will continue to revisit us -- with a vengeance," he wrote in the "The Year of Living Dangerously."

Vehicle exhausts and power plant pollution are largely the culprits in two major countries: China and the United States -- in that order, according to climate reports.

Weiss said the U.S. has made progress on car exhaust but still has a long way to go on power plant pollution.

Two proposals seeking change have not gotten to the president's desk, he said. On party line votes, the House of Representatives earlier this year defeated an amendment that says climate change is occurring. The amendment was offered by U.S. Rep. Henry Waxman, D-Calif., and it would have accepted the scientific findings of the Environmental Protection Agency stating the change is caused largely by human activities and poses significant risks for public health and welfare.

Another bill was a basic proposal to address the problem. The market study done for the bill found that carrying out the proposal would cost American households about $25 a year.

Weiss and others have warned that time for action is running out.

To add insult to injury, Weiss said the House voted to defund federal science programs that gather and analyze the data essential to understand changes in global weather patterns and other climate impacts.

"But all this denial cannot make this threat disappear," Weiss' report states.

Predicting weather

Forecasters are in full agreement that climate change is contributing to record rains and floods, but generally they are still iffy on what impact the warming oceans have on tornadoes. More goes into making tornadoes, Carbin said, than just warm air and moisture. There also has to be a good dose of cold air in the upper atmosphere to create wind shear.

But he said researchers have made good progress on predicting the weather patterns that make tornadoes likely.

And that's what forecasters used in the days leading up to April 27.

The bad weather alerts they issued likely helped keep the record outbreak's death toll -- 547 --below the all-time tornado death record. That still is held by the March 18, 1925, Tri-State Tornado that claimed 695 lives in Missouri, Illinois and Indiana -- long before warnings were available.

"There have been 14 outbreaks over 135 years that killed 200 or more people," Carbin said, adding that clusters of deaths prior to 1950 happened largely because the tornadoes came with little notice.

"Since the 1950s, we can get the word out better," he said.

But that warning still comes down to a matter of minutes -- on average, almost 14 minutes. In the late 1970s, the average was three minutes.

"Science is just not at a point yet where I can give you a three-hour window that a tornado is coming," Carbin said.

In April, two days before the record tornado outbreak blasted across Dixie, the National Weather Service was calling emergency responders and posting weather bulletins for the public and the media.

In Chattanooga, reporters from several media outlets were invited to the 911 Center to hear Weather Service assessments of a dangerous weather pattern likely to spawn supercell thunderstorms and twisters.

"That's a testimony to the progress we've made in forecasting," Carbin said. "But the devil is always in the details. We can do it on a large scale -- like states. But we can't get it down much from there yet."

Aside from forecasting, there are needs for other tornado and extreme weather research.

Carbin said tornadoes in recent years have caused more fatalities in the South than in the Midwest.

The Southeast is more vulnerable because of less stringent construction codes, and the population is more dense, he said.

In the end, he said, there's no such thing as a 100 percent certainty about tornadoes until an event occurs.

"That's the nature of nature. It's going to hide its secrets until it does what it will do," Carbin said.

  • photo

Watch Channel 3 or visit today at 5 p.m. and 6 p.m. for inspiring stories of life after the storm. Chief Meteorologist Paul Barys meets the people who were watching the Storm Alert 3 Team on April 27.

about Pam Sohn...

Pam Sohn has been reporting or editing Chattanooga news for 25 years. A Walden’s Ridge native, she began her journalism career with a 10-year stint at the Anniston (Ala.) Star. She came to the Chattanooga Times Free Press in 1999 after working at the Chattanooga Times for 14 years. She has been a city editor, Sunday editor, wire editor, projects team leader and assistant lifestyle editor. As a reporter, she also has covered the police, ...

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rdecredico said...

"Some weather forecasters have suggested Tornado Alley, a swath through the Great Plains and Midwest that has seemed most prone to tornadoes, has shifted eastward to bring the killer tornadoes seen in the Chattanooga region this year."

Really? Who are they?

"But the tornadoes that mauled the Southeast six months ago were the super outbreak of all time."

According to whom?

I find statements such as these, when made in a 'news' story to be misleading at best and possibly spurious and disingenuous at worst in part because there is no clear attribution cited for either claim and also because the 'history' of 'all time weather' events is a rather short sighted human affair since we only have less than 150 tears of data, and most of it is unreliable.

We have more sensors and stations and sites reporting data now than we did 50 years ago, and storm intensity is too often gauged by damages in dollar amounts, which are prone to rising because we have a) more people now than before and b) economic inflation.

Interesting subject and ripe for a real investigation that goes a bit deeper than speculative jabs and AGW agenda driven jargon and meme speak.

October 27, 2011 at 12:44 a.m.
ditdahdit said...

Before I started reading this article, I knew it was going to be another "Global Warming" fluff piece. I'm surprised that there wasn't a quote saying that "This was Bush's Storm Outbreak". My prediction for the next big weather disaster for the Chattanooga area is a big ice storm. Blame that on "global warming"!

October 27, 2011 at 8:38 a.m.
callison said...

ditdahdit, that is the kind of statement I would expect from an uneducated Tennessee redneck. How stupid can you be?

October 27, 2011 at 9:01 a.m.

Weather happens.

Predictions and warnings could be given days in advance then nothing (or very little) could happen. So we get apathetic. The next warnings go unnoticed and people get killed.


I, too, predict an ice storm this winter. Followed by high heat and humidity. I'm certain of it.

October 27, 2011 at 9:41 a.m.
nowfedup said...

Well by the dumbed down remarks posted by a few, it seems TN will hang on to the record of nearly worst state for education. Simply cannot believe how stupid, head in sand some have become, more so for the political gains of a few, some more profits and greed. Same ilk always howling about "save our kids future". Yet despite overwhelming evidence that "warming is dangerous and happening" backed by sat photos that show Artic ice melts increasing, will be new shipping routes very soon, they continue their Ostrich head in ground ways. THE KIDS FUTURE is NOW when it comes to warming, we control it. Future generations will look back and ask "Why did they do this to us?" Even latest study has changed minds of skeptics

The sorry truth is some of the posting by the more ignorant and uniformed is an embarrassment to us all.

Way past time to push for new controls, universally accepted time is running out for major over changes in how we handle pollutions. Either we do something soon or get on the tigers back for the ride as no getting off. Guess the education systems have failed more then the data provides, some of elected via their rhetoric's, to appeal to lowest common denominator of intelligence for votes, even dumber then their supporters. Way past time many get someone to explain just how Mother Nature handles those the upset her balanced world, and she will be harsh. What a bunch of fools that cannot accept this dangerous reality.

October 27, 2011 at 12:51 p.m.
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