Climate Cast: Putting the Moore tornado in the context of Climate Change

Every Thursday MPR meteorologist Paul Huttner joins Kerri Miller on The Daily Circuit for “Climate Cast” on MPR News Stations to talk about the latest research on our changing climate and the consequences that we’re seeing here in Minnesota and worldwide.

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These days it seems like we are witnessing climate changes unfold right before our very eyes.

It’s not our imagination.

The nature of our seasons is changing. Spring blooms come earlier. Summer is more humid with a documented increase in extreme localized flash flood events…and more frequent droughts. Fall lingers longer. Lakes freeze up later. Winters are trending shorter and noticeably, measurably milder. New plants are able to thrive in Minnesota’s milder climate.

We’re all living witnesses to rapid climate changes in our lifetime. This is no longer your grandparents “Minnesota.”

In 2013 at MPR we’re devoting more coverage to the science behind and the growing effects of our changing climate in Minnesota and around the globe.

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Before and after images of Briarwood Heights Elementary in Moore, Oklahoma.

You can hear me discuss the week’s top climate stories in our new “Climate Cast” every Thursday morning at 9:50am with Kerri Miller on The Daily Circuit.

Climate Cast for May 23rd, 2013

Tempting as it is to chalk up a severe weather event to climate change, the killer tornado that hit Oklahoma has no clear link to global warming, according to Paul Huttner, the Chief Meteorologist for MPR News.

Putting the Moore, Oklahoma tornado in the context of climate change.

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Damage path of the Moore, Oklahoma tornado. Check out NPR’s interactive zoom tool.

Moore, Oklahoma: Ground Zero in Tornado Alley

Incredible timelapse of Moore, OK tornado captured by an Oklahoma City news helicopter Monday

If there is an “Epicenter” in Tornado Alley, it has to be Moore, Oklahoma.

The Oklahoma City suburb has seen 3 direct hits from EF-4 to EF-5 tornadoes in the past 14 years.

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Image credit: Weather Decision Technologies

Jeff Masters has noted that the latest Moore tornado likely to be one of the five most damaging tornadoes in history.


The Moore, Oklahoma tornado of May 20, 2013 is now ranked an EF-5, making it one of only 59 U.S. tornadoes to achieve that distinction since record keeping began in 1950. The National Weather Service in Norman, Oklahoma announced Tuesday that their damage survey teams found an area of EF-5 damage near Briarwood Elementary School, with winds of 200 – 210 mph indicated.

There were no EF-5 tornadoes observed in 2012, and the last time the U.S. had an EF-5 was on May 24, 2011, when the Oklahoma towns of Calumet, El Reno, Piedmont, and Guthrie were hit by an EF-5 with 210+ mph winds that killed nine people. The maximum width of the 2013 Moore tornado’s damage swath was a huge 1.3 miles. Detailed damage survey information in Google Earth Format provided by the Norman, OK NWS office shows that the typical width of the EF-0 and greater damage swath was about 0.6 miles, and the EF-4 damage area was about 0.1 miles across at its widest. EF-4 damage occurred along approximately 4 miles of the tornado’s 17-mile long path. The damage swath from the May 20, 2013 tornado as it cut through the most densely built up portions of Moore was roughly 1.5 times as wide as the one from the May 3, 1999 EF-5 tornado. That tornado was the 4th costliest in history ($1.4 billion 2011 dollars), so it is a good bet that the 2013 Moore tornado will end up being even more expensive. This morning, the Oklahoma Insurance Department said the preliminary tornado damage estimate could top $2 billion. This would make the 2013 Moore tornado the 2nd most expensive tornado in history (as ranked by NOAA/SPC) or 3rd most expensive (as ranked by insurance broker Aon Benfield.) The nine billion-dollar tornadoes (2013 dollars) are:

1) Joplin, Missouri, May 22, 2011, $2.9 billion

2) Tuscaloosa, Alabama, April 27, 2011, $2.3 billion (not in SPC’s list)

3) Moore, Oklahoma, May 20, 2013, $2 billion

4) Topeka, Kansas, June 8, 1966, $1.8 billion

5) Lubbock, Texas, May 11, 1970, $1.5 billion

6) Bridge Creek-Moore, Oklahoma, May 3, 1999, $1.4 billion

7) Hackleburg, Alabama, April 27, 2011, $1.3 billion (not in SPC’s list)

8) Xenia, Ohio, April 3, 1974, $1.1 billion

9) Omaha, Nebraska, May 6, 1975, $1 billion

But is climate change a factor in producing more of these these monster EF-5 tornadoes?

Probably not.

Some facts:

-Oklahoma City has suffered the most direct tornado hits of any US city…at least 100 since 1890.

-Overall tornado stats show no real “frequency trends” to suggest a clear connection between violent tornadoes and climate change.

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Image: NOAA

-EF4 & EF5 tornadoes compose less than 1% of all tornadoes…but produce 70% of tornado fatalities.

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Image: tornadoproject.com.

-Warming trends in the US may produce more T-Storms overall, but also may create less wind shear that is necessary for tornado formation.

-There is some evidence tornado alley may be expanding northward. Annual average tornado numbers in Minnesota have nearly doubled since the 1950s.

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-My analysis of SPC data for the past few decades shows the number of tornadoes in Minnesota has actually trended closer to Oklahoma. The chart below shows tornado numbers by decade since the 1950s. Oklahoma is the top line, Minnesota below.

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Bottom line: There appears to be no discernible link between climate change and the increase in frequency of violent tornadoes in the US. There may be some evidence “Tornado Alley” is expanding northward.

Here’s the NOAA “State of the Science Fact Sheet” on what we know, and don’t know about climate change and tornadoes.

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Thankfully EF-5 tornadoes over 1 mile wide are rare beasts.

Climate Central’s Andrew Freedman has another look at how the Moore tornado fits in other bigger context of climate change.


Based on data from 1982-2011, Oklahoma City was the likeliest spot in the country for seeing severe thunderstorms on May 20. Tornado statistics show that the Oklahoma City metro area has had the most direct tornado hits of any American city, with at least 100 since 1890. That’s according to the Storm Prediction Center in Norman, Okla., which is situated just down the road from Moore, and whose forecasters were forced to take shelter as the storm moved through.

Similarly, there is no evidence to indicate that EF-4 and EF-5 tornadoes — like the one that decimated a large swath of Moore — are becoming more frequent or severe. Such tornadoes are rare — they comprise less than 1 percent of the total number of tornadoes — yet they are the most reliable killers, accounting for 70 percent of tornado fatalities. The record annual number of EF-4 and EF-5 tornadoes occurred in 1974, when 36 such tornadoes scarred the landscape of the Midwest and Great Plains. Between 2000 and February of this year, there were 129 EF-4 and EF-5 tornadoes, according to a Storm Prediction Center database.

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Disappearing mountain snow cover: An important indicator of climate changes

Mountains are like water towers around the world. They collect and store massive amounts of snow and ice, then give it back as water through snowmelt in the warm season.

Recent trends show a clear signal that high mountain snow and ice is disappearing faster in spring that it did 50 years ago.

Tim Radford from Climate News Network has more.


LONDON – Around 20 percent of the snow cover in North America’s greatest mountain range has been lost – because of warmer springs in the last three decades.

Scientists from the American Geophysical Union and the U.S. Geological Survey report that they had established a pattern of snowfall in the northern and southern Rockies: when the snowpack was large in the northern Rockies, it might be correspondingly meager in the southern mountains and vice versa.

But since the 1980s, snowpack declines have occurred simultaneously along the entire length of the Rocky Mountains, with unusually severe declines in the north.

"Snow deficits were consistent throughout the Rockies due to lack of precipitation during the cool seasons during the 1930s - coinciding with the Dust Bowl era."

"From 1980 on, warmer spring temperatures melted snowpack throughout the Rockies early, regardless of winter precipitation," said Greg Pederson of the Northern Rocky Mountain Science Center in Bozeman, Montana.

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Climate Change Mitigation: What you can do

Let’s fact it, Climate Change can seem like an overwhelming problem with few easy solutions.

Many of you have asked what you can do in your lives to combat and mitigate the impacts of climate change.

Here are some great resources from NASA and EPA.

NASA: Resources on Climate Change mitigation

EPA: What you can do about Climate Change

EPA: Regional impacts of Climate Change

Climate Cast resources:

Want to know more about climate change? Here are few quick links to credible climate change sources.

-Read the Minnesota Public Radio primer on Climate Change

-NOAA NCDC’s “State of the Climate” report

-AMS Statement on Climate Change

-NASA key evidence of climate change

-Great summary of Modern Day Climate Change from SUNY-Suffolk

-Minnesota Climate Working Group climate change resources

-Mark Seeley’s Weather Talk

-Common climate change myths

-Climate change in the news from Climate Central

-More coverage from The Yale Forum on Climate Change and Media

Paul Huttner

  • Cody Y

    “There is some evidence tornado alley may be expanding northward. Annual average tornado numbers in Minnesota have nearly doubled since the 1950s.”

    Of course it has. The number of tornadoes has increased everywhere. There are more people around watching for them, much better means of detection, and much better damage surveying.

  • Al Bore

    What science needs to say to end the debate is:

    “Climate change crisis will happen and is inevitable if CO2 mitigation does not occur.” as opposed to: “Climate change is real and is happening and could cause a climate crisis.”

    Only a comet hit could be worse than a climate crisis so why won’t science say their crisis is as real as they like to say comet hits are? Don’t the scientists have children who are doomed as well?

  • Meme Mine

    MPR needs to stop this silly fear mongering of climate blame and get up to date:

    *Occupywallstreet now does not even mention CO2 in its list of demands because of the bank-funded and corporate run carbon trading stock markets ruled by politicians.