From the American Geophysical Union | WASHINGTON, D.C. – Peak tornado activity in the central and southern Great Plains of the United States is occurring up to two weeks earlier than it did half a century ago, according to a new study whose findings could help states in “Tornado Alley” better prepare for these violent storms.
Tornado records from Nebraska, Kansas, Oklahoma, and northern Texas – an area of high tornado activity dubbed “Tornado Alley” — show that peak tornado activity is starting and ending earlier than it did 60 years ago.
Peak tornado activity, which occurs in the region from early May to early July, has moved an average of seven days earlier in the year over the past six decades. The study’s authors observed the shift in tornado activity for all categories of tornadoes that occurred in the region from 1954 to 2009.
The research team published its findings last week in Geophysical Research Letters, a journal of the American Geophysical Union.
Additional, more-selective analyses by the authors show that for some states in the region and for stronger tornadoes the season advances an average of 14 days compared to 1954.
“If we take Nebraska out [of the data], it is nearly a two-week shift earlier,” noted John Long, a research scientist in the Department of Land Resources and Environmental Sciences at Montana State University in Bozeman, Montana, and lead author of the new paper. For tornadoes rated above F0, the lowest rung on the original Fujita scale of tornado strength, the shift is also close to 14 days, according to a preliminary analysis by Long and his colleagues that’s not included in the new paper.
F1 tornadoes have winds between 117 and 180 kilometers per hour (73 and 112 miles per hour), while the strongest tornadoes, F5, have winds between 420 and 511 kilometers per hour (261 and 318 miles per hour), according to the original Fujita scale. Although the Fujita scale was updated in 2007, Long and his colleagues stayed with the original Fujita scale because most data in this new study originates from prior years.
The new research does not attribute the shift in tornado activity in the region to any single cause. However, the earlier tornado activity seen in the study is in-line with what could be expected in a warmer climate, the study’s authors said.
The new research could help residents in the region be better prepared for severe weather, said Long. About 1,300 tornadoes hit the U.S. every year, killing an average of 60 people, according to the National Weather Service’s Storm Prediction Center. This year, the majority of the 309 tornadoes that have hit the U.S. occurred in May and the deadliest storms were in April, according to the Storm Prediction Center.
“From a public safety perspective, if this trend (of an earlier tornado season) is indeed occurring, then people need to begin preparing for severe weather earlier in the year,” said Greg Carbin, the warning coordination meteorologist at the Storm Prediction Center in Norman, Oklahoma, who was not involved in the new study.
The new research analyzed National Weather Service tornado data for Tornado Alley from 1954 to 2009. The authors broke the data into ten-year time frames and analyzed how the dates of peak tornado activity changed over time.
The analysis showed the date of peak tornado activity in the region moved earlier at a rate of 1.55 days per decade over the time period studied. In the heart of Tornado Alley, an area with the highest density of tornadoes, peak activity shifted by seven days: from May 26 in the 1950s to May 19 in the early 2000s.
Although there is a consistent movement in the region toward earlier tornado activity, it is difficult to pinpoint a cause, said Paul Stoy, assistant professor in the Department of Land Resources and Environmental Sciences at MSU and co-author of the new study. Records of tornado activity in the U.S. only date back to the 1950s, making it difficult to study changing trends in tornado activity. Furthermore, tornadoes can be influenced by many regional factors, including topography of the land and areas where cooler air meets warm, subtropical air, making it difficult to attribute the shift in the tornado season to any one factor, he said.
Carbin, of the Storm Prediction Center, said a warmer climate might play a role. “If winters are not as cold, or if spring times are warmer, the location of the jet stream is most likely displaced north of where it has been in the past,” he said. This would cause tornado activity to shift earlier in the year, like what is seen in the new study, Carbin said.
The study has revealed a connection between one global climate pattern and tornado activity, specifically in the state of Oklahoma. When El Niño conditions occur between January and April, peak tornado activity in Oklahoma occurs earlier in the spring, the researchers report. El Niño, an oscillation of the ocean-atmosphere system that is associated with warm ocean waters in the Pacific Ocean, changes the air surface pressure and atmospheric circulation.
“The relationship we do see in Oklahoma is a light but significant connection to El Niño,” Stoy said. “This makes one suspect that if global climate change is changing these larger circulations, then there is a connection between a global [variability] and tornado activity.”
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Starting 2 weeks earlier, and ending 4 weeks earlier. Guess that is why Tornadic activity is so low these days.
“The new research does not attribute the shift in tornado activity in the region to any single cause. However, the earlier tornado activity seen in the study is in-line with what could be expected in a warmer climate, the study’s authors said.”
Tornados starting earlier, tornados starting later, it’s all “expected in a warmer climate”. In other words, regardles of what is happening, blame it on AGW.
John, be fair, that is a de-rigeur requirement in any research paper these days or it will not be published:
[name subject of paper] seen in the research is to be expected in a [warmer climate|due to climate change]”
In some less reputable journals, the phrase seems to be added to most articles almost regardless of subject. I would have thought to add such a phrase – which is really a hypothesis – there should be some kind of justifying reference back to the study results and how they fit with claimed change in climate.
Those papers and journals will look silly and contemptible in the future!
Yes, “how they fit” is ALWAYS the important issue. If they can’t point to the mechanism and SHOW the connection, then it is all speculation and surmise.
NOTHING counts in science AS science, if it isn’t shown empirically to be true.
The old publish trigger phrase was “Nuclear Winter”
Those who would stay in the good graces of the Lysenkoists must say the shibboleth and utter the ecco la fica. And yes, those who include such tripe in current papers will regret displaying their obvious venality in years to come. Science is dead.
Actually, I did not read that they blamed it on AGW. And, yes, the climate is warmer (marginally) than 60 years ago. If this study passes the real peer review (the one that happens in the market of ideas, rather than in the usual peer review process) this is interesting. I am especially intrigued (as a trained geographer) as to why Nebraska is such an outlier that removing it from the mix shifts the remaining region by an extra week. Nebraska is in the central area of tornado alley using the map above.
There is no “the climate”. Some places are warmer, some places are cooler, some remained relatively static. You can’t average them together and get anything physically meaningful.
The new research does not attribute the shift in tornado activity in the region to any single cause. However, the earlier tornado activity seen in the study is in-line with what could be expected
in a warmer climatefrom interference by aliens, the study’s authors said.“Tornados starting earlier, tornados starting later, it’s all “expected in a warmer climate”. In other words, regardles of what is happening, blame it on AGW.”
“Although there is a consistent movement in the region toward earlier tornado activity, it is difficult to pinpoint a cause, said Paul Stoy, assistant professor in the Department of Land Resources and Environmental Sciences at MSU and co-author of the new study. ”
folks need to understand how a “consistent with” argument works.
I believe the criticism is that everything seems to be “consistent with” AGW theory. Also, while the study does not mention AGW, certain activists will deliberately, conveniently and false claim climate change is human induced.
“Consistent with” is a phrase that does not belong in the conclusions of a scientific paper. It says nothing about the truth or falsity of the hypothesis. Mr Stoy might easily say “although there is a consistent increase in several indices of obesity among teenagers in the region it is difficult to pinpoint a cause”.
A better summary statement would be “The fact that the Nebraska data , at the center of ‘tornado alley’, has such a marked effect on the data analysis would seem to indicate that a warmer climate in the region is not a potential cause of the measured change.
Absolutely. The decrease in American lightning deaths is “consistent with” the theory that every 25ppm of added CO2 decreases God’s anger by half.
i.imgur.com/PnucUsf.png
Sorry, PNG image did not work. I will try JPG.
http://i.imgur.com/zvVjwBs.jpg
I don’t buy the 2 weeks earlier for F0 tornadoes since we invented dopplar radar and can see every one of them now.
We also are more populous and media excitement over a possible CAGW pointer adds to the reporting cycle.
Probablt little changed.
Probably!!! ( finger trouble)
MattN
You have a point. Old records are bound to be imperfect when compared to the Doppler radar era.
‘The new research does not attribute the shift in tornado activity in the region to any single cause. However, the earlier tornado activity seen in the study is in-line with what could be expected in a warmer climate, the study’s authors said.’
But there again, what isn’t?
I might also point out that weather radar is a rather recent invention, early tornados were quite likely under reported, wonder if they bothered to compensate for that, or just assumed that measuring technology never changes.
And thinking of the explosion of subdivisions covering much more space, I’m sure many were never visually confirmed back then.
Where do I start? Data only goes back to 1954. There is no data for other warming periods in the history of the earth. Since they can’t separate out the causes to determine the relative impacts of each cause on this hypothesis (I won’t even ask for absolute numbers) I don’t see how this hypothesis is even useful.
Because having spring arrive a little sooner is just a catastrophe! But as with a lot of these studies their claim is probably wildly inflated and the truth is more like 7 hours.
“Peak tornado activity in the central and southern Great Plains of the United States is occurring up to two weeks earlier than it did half a century ago…
[…]
From a public safety perspective, if this trend (of an earlier tornado season) is indeed occurring…”
= = = =
Looks like Bill Clinton’s proprietary version of “is.”
And so far as the advice to” prepare earlier”, the people living in tornado alley are always prepared for violent weather.
The “Prepare earlier” advice amuses.
The NWS will issue an advisory that persons living in tornado alley can expect to get sucked up into the ether earlier than usual.
..according to a new study whose findings could help [squealing rent seeking pseudo scientists and their political masters]…
“Wherever there is a trough,” wrote the Russian poet Alexander Pushkin, “there you will find pigs.”
Oink! Oink!
Records of tornado activity in the U.S. only date back to the 1950s….
Did Dr. Stoy really say this?
Image above showing location of Tornado Alley:
http://wattsupwiththat.files.wordpress.com/2014/09/tornado_alley.png
From USGS on the severe anthropogenic aquifer depletion:
http://water.usgs.gov/edu/graphics/gwdepletion-map-2008.png
Note how the terrible aquifer decline in that area, which may take a thousand years or more for recovery, lines up with Tornado Alley. The aquifer decline comes from primarily irrigation.
So over time as irrigation became more widespread, with fields of green soaking up sunlight during the day leading to changes in the local climate with the air warmer and more humid, the tornado timing shifted.
Were they expecting in a warmer climate that locally it would be warmer and more humid?
Surface evapouration causes surface cooling because of the latent heat requirement. Tornadoes form from supercell Cb’s in cold fronts so a cold northerly air mass trying to mix with the wet Gulf air mass looks like a cause. The greater the air mass relative temperatures would, I think, cause larger tornadoes so cooling is more likely to cause them not warming.(In a warming planet the polar regions warm relatively faster than the equatorial regions leading to a smaller temperature difference. Cooling planet the opposite will apply, equatorial regions cool slower leading to a greater temperature difference.)
Remember the Dust Bowl. Previously that area was referred to as “The Great American Desert”. Semi-arid prairie. Changing such dry light-colored land to irrigated fields of green is an albedo change, more solar radiation absorbed, more warming.
So darker fields with more warming, and moister air with a higher heat content transporting more warmth skyward.
There’s also the increased nighttime warmth from the added water vapor slowing down the heat loss.
Previously on WUWT a paper was mentioned showing irrigation causing ‘significant cooling of global average surface temperatures over land’.
You are right the evaporation causes surface cooling. Which actually means it causes the rising air to have greater heat content than otherwise, and the albedo change has made even more thermal energy available for transport upwards.
Actually, with more vegitation, the local climate would be cooler. Stand on a unpaved road in sunlight, then walk into a field of crops and I guarantee you’ll feel the difference in temperature.
Yes, but they both receive nearly the same heat from the sun, so the heat must have been carried away in the form of evaporation which cools the surface. The heat is still there, just overhead in the form of rising water vapor. (Though there is a significant difference in albedo between the green plants and a black asphalt road, there is less difference between an asphalt road and a field of corn then there is between that same road and an arid, dry-grass, light-tan landscape – the tan gets much hotter than the green only because the green has more water vapor to carry away the heat.)
In some greenhouse experiments I did as a kid, the dark green barrels of water heated faster than the black barrels of water, so we used dark green barrels in the passive solar heating system we set up on the south side of the house. That Just says that the amount of difference in raw heat absorption between the field and the asphalt may not be as much as one would expect. Even though the field is much more comfortable and shows a lower thermometer reading at the peak of the day.
The role of the plants in the process cannot be ignored. The plants intercept the sunlight before it hits the ground. The plants then use the sunlight in the process to create plant matter. That energy is no longer heat and will not radiate. A dense stand of plants shades the ground, slowing evaporation of soil moisture. If there is increased evaporation it will be from evapotranspiration according to the needs of the plant and my not be directly in response to the sunlight received.
This report is rather myopic. Trying to draw scary conclusions has muddied the reality of slightly decreasing tornado frequency and strength http://wattsupwiththat.com/2014/08/25/u-s-tornado-intensity-index-shows-no-upward-trend/. Did anyone ask if decreasing activity and strength have resulted in a shorter season with a correlated earlier peak activity window?
Reblogged this on gottadobetterthanthis and commented:
Anthony uses the “Claim” in titles when he is skeptical of what he is reporting on. I call the article hogwash. The American Geophysical Union has no credibility in my view.
The point about El Nino is significant. El Nino matters. El Nino is an emergent, chaotic process driven by the sun. Anyone that thinks even 10 billion people can affect the Pacific Ocean has severe ego problems.
What are the tornado numbers this yr? According to climacrats, should be more than evah. And how ’bout all them harry-canes this yr? And we won’t know what snow is this coming winter either (/sarc).
If we remove some inconvenient data, we can clearly show whatever we want …
I agree that removing NB is illegitimate as a general method. Still, why is Nebraska an outlier. Answer that question and we may uncover a more interesting answer (or that the data is truly random). Either way, exploiting rather than ignoring the data is the key.
This claim fails the sniff test.
The most extreme tornado in the USA was the Tri-State Tornado, which roared through parts of Missouri, Illinois, and Indiana on March 18, 1925. It was likely an F5, lasted around 3.5 hours, and had an across the ground speed of 73 mph. It killed around 700 people.
The so called Super Outbreak of 1974, which occurred during a period of cooling, happened on April3 and 4 and involved 148 tornadoes over the USA and Canada which killed over 300 people.
I could be wrong, but– I notice a tendency by some to remove any data that doesn’t support their theory. “If we remove Nebraska from the data we get”— Excuse me, but Nebraska is right in the heart of the mix, along with Kansas.
Could there be a strong tendency to remove any data that conflicts with our preconceived notions?
Well, you know if we remove all the murders from the statistics of Chicago, it is the safest place in America.
What is the rational for this : “If we take Nebraska out [of the data], it is nearly a two-week shift earlier,”
The rationale is to take a non-issue and turn it into yet another example of human-induced catastrophic climate change.
I just downloaded the data from the NOAA covering 1950 to 2013. There are 59,000 tornado counts in the database and there is no way one can accurately say that tornados are occurring earlier now than they use to (one could make something up but it would not be a true reflection).
http://www.spc.noaa.gov/wcm/index.html
For example, here is the tornado counts by the time of the year (0 to 0.999 being December 31st) for the decades of 1950 to 1960 versus 2000 to 2010. I tried other decades. There is no way to make this claim accurately with this data.
http://s27.postimg.org/kem7ckvdv/Tornado_Counts_by_Time_of_Year.png
Another view.
http://s3.postimg.org/sxfm87903/Tornado_Counts_by_Time_of_Year50s2000s.png
Actually, this graph would indicate that tornados were more frequent in the 2000-2010 decade cery early in the year. If I’m understanding the X-axis correctly, we’d be talking January. I think you’d need to graph each one month period with the 5 decadal points for that month and see what the regressions looked like.
Exactly! Removing irritating data that ruins the theory is how all the climate ‘scientists’ operate these days. They do this to temperature data, they got rid of the Medieval Warm Period this way, etc. No shame! At least they admitted to doing this in the case of this tornado ‘study’.
Take out Nebraska? Why would you take out Nebraska? Did an exceedingly large portion of the tornadoes happen to fall in Nebraska over the study period? Was that inconvenient for you? Jeez, are you people insane? And too, Nebraska was why we couldn’t build the Keystone XL pipeline, remember? There were going to be threats to the Ogallala aquifer from oil spills from the pipeline in Nebraska. Nebraska has Warren Buffett, and the College World Series, and the Omaha zoo. You can’t take out Warren Buffett. Nebraska keeps Wyoming from crashing into Iowa. It keeps South Dakota from falling onto Kansas. YOU CANNOT REMOVE NEBRASKA! Put it back, immediately, or so help me, I will and make a citizens arrest and a citizens revocation of your funding grant..
I have just done a study (in the AGW method – I guessed) that tornados decrease 10% for each 100 parts per million of CO2. So we can end tornados if we can get the CO2 level to 1400.
They never, never, EVER say WHY anything is expected in a “warming climate”, they just assert and run.
Hmm… and spring frosts are getting later in Australia. WUWT had a piece a week ago and:
http://iceagenow.info/2014/09/severe-frost-damages-southern-australia-crops-video/
I guess the alarmists have abandoned the southern hemisphere because it isn’t cooperating, especially before the NY Slummit. I hope we get to see some litigation against institutions that have encouraged farmers and other private enterprises to act on the propaganda of the ‘clime syndicate’ (thank you Mark Steyn for this term). After the Ship of Fools got caught in “unprecidented” summer ice in Antarctica and now the ice has expanded to huge new records (over 16.4 million sq km today), let me make a forecas: Farmers, there are going to be late spring frosts for the foreseeable future! In Britain, huge downpours in 2012 when the month before a hot dry spring was being touted and the warm winters that turned out to be bitter cold with record snowfalls from coast to coast with no preparedness and huge costs to individuals and businesses. Someone has got to pay for all this. The tornadoes? Here is another forecast: as global temperature drops, there will be later and more tornadoes like there used to be.
Although there is a consistent movement in the region toward earlier tornado activity, it is difficult to pinpoint a cause, said Paul Stoy
================
how about improved detection and reporting? Maybe what has changed is the speed of reporting.