Tornadoes and global warming – still no linkage

While Joe Romm, Bill McKibben, and others follow the fear card script to do everything and anything they can to link severe weather to global warming, they are clearly fighting a losing battle for public opinion on the issue. Now, even Andy Revkin at the New York Times doesn’t believe it anymore when it comes to tornadoes.*

He writes:

You can’t exclude climate change, but there’s simply no evidence through a half century of tornado history in the United States of a connection to warming.

Of course one of the strongest pieces of evidence has to do with the trend in the frequency of strong tornadoes, as shown in this somewhat dated graph from NCDC:

https://i0.wp.com/www.ncdc.noaa.gov/img/climate/research/tornado/tornadotrend.jpg?resize=630%2C496

I’m looking forward to NCDC updating this data and graph. Obviously, there will be a new spike in 2011 rivaling 1974. But clearly, even with improved detection technology, the trend is down.

But this graph only goes back to 1950, and of course if we presented climate data only back that far, critics like the nefarious “Tamino” aka Grant Foster would have a cherry flavored cow, which is the typical M.O. for him. NCDC of course gets a pass.

Fortunately, I have some new tornado data to present that goes back further.

These two graphs below, courtesy of Dr. Indur Goklany, go back to 1900 and show the trend in death rates yearly, and by decade, since 1900:

Clearly death rates per million are down, which is testament to the improved warning technology, plus the skills and dedication of the National Weather Service and volunteer storm spotters at getting “eyes on” tornadoes to provide advance warning.

*UPDATE: Andrew Revkin writes in via email with this comment, which I am happy to reprint at his request – Anthony

You’ve cast my concerns about overstated discussions of tornadoes in the context of climate change as if this is new.

You must have missed my 2008 piece, including this section:

http://dotearth.blogs.nytimes.com/2008/02/07/climate-roundup-tornadoes-coral-drought/

Frequency of strong (red) and weak (blue) tornadoes since 1950.

 

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sandyinderby
May 27, 2011 12:04 am

Should that be 2011? in
there will be a new spike in 2001 rivaling 1974.
REPLY: Typo fixed, thanks – Anthony

May 27, 2011 12:09 am

Sadly, my Geography 5 teacher at Santa Monica College is going to pin the increase in deadly tornadoes on climate change and the increase of water temperature of 2 deg. C in the Gulf of Mexico. I should bring this article to class and show then climate change has nothing to do with the increase of the current tornado outbreak. She also doesn’t want to admit that volcanoes contribute to global cooling. Go figure.

Torgeir Hansson
May 27, 2011 12:13 am

Tornadoes, schmornadoes. Where I live we worry about earthquakes, and they are definitely tied to warming. It was warmer in 1989 than in 1906, and there was an earthquake in both years. And both happened on a warm day, at least compared to some of the days when there was no earthquake.
Say no more.

Adam Soereg
May 27, 2011 12:16 am

Obviously, there will be a new spike in 2001 rivaling 1974. But clearly, even with improved detection technology, the trend is down.
Don’t you mean 2011 as comparable to the 1974 spike? This must be a typo.

Al Gored
May 27, 2011 12:27 am

I think I just realized what may have inspired the movie The Wizard of Oz.

Jake
May 27, 2011 12:28 am

Does the shown graph, outdated as you say, go through 2005 or 2010? Hard to tell.

Scottish Sceptic
May 27, 2011 12:35 am

It is interesting. I saw the graph on tornado numbers, and said to myself: “if anything they are going down … I wonder why that is … is there any change in the way these are recorded”.
Next I wondered whether rising CO2 could have reduced the number of tornadoes at which point a bottomless bit of boiling speculation opened up and I chose not to enter in.

Interstellar Bill
May 27, 2011 12:59 am

Don’t tornadoes need a mass of quite cold air to collide with a ‘normal temp’ air mass? Slightly warmer Gulf air or not, if there’s no frigid air-mass there’re no tornadoes, just giant dust devils.
The warmist fear-mongers shouldn’t be so eager to trumpet what are actually the results of global colding.
They even gamely tried to pin the cold winter on their fantasies.
A few more cold summers may finally provide something they won’t admit even exists, namely, a disproof of AGW, especially when it goes on for decades.

Eyal Porat
May 27, 2011 1:14 am

If anything, the graph may show we are cooling.
The spike of tornadoes was in 1974 – “we are approaching an ice age” era, remember?

Alan the Brit
May 27, 2011 1:45 am

The trend seems to be clear! Of course it’s all too easy to forget that we live in age of near instantaneous communication of events around the world, that barely 50 years ago would have taken hours or days to establish, & 100 years ago, days & weeks to confirm! Media (& anthrotechnology), if nothing else, has improved speed of communication. Whether the accuracy of same has improved would be considered a moot point IMHO. So we have disaster upon disaster shown to the world at large at lightening speed, as if it were something unusual or even new, with no reference point from which to judge its validity, other than to append the usual “worse for 25/50/100 years” , (tick whichever is appropriate) banal remark.
OT Nice speech by your President, starting with some much shared humour, but of little substance in most of it other than the usual trite statements. I have nothing personal against the man, the Democrats were in their usual turmoil of “who do we run with, the first woman (Clinton) or the first black (Obama) candidate?” AND NO I am neither misogynist or racist, just C of E & an observer of people! Similar traits to President Kennedy he knows how to work a crowd, even if they are the lame-brain dead self-promoting self-enriching (at taxpayers expense) British politicians who couldn’t give a damn about anyone but themselves so long as the stupid prols believe they are doing good, but then I am biased, as many of you may deduce I have absolute admiration & respect for our political classes 🙂 Sarc off!

Ian H
May 27, 2011 1:49 am

I like the fitted straight line predicting negative deaths from Tornadoes about now. I hate the way in climate science every graph gets a straight line drawn on it which is immediately it seems abused to predict calamity a hundred years into the future. This graph provides a great example of what is wrong with this practice.
According to this graph dead people who have not been killed by tornadoes should start popping up out of the ground any day now. Zombie invasion anyone?

Ryan
May 27, 2011 2:32 am

In this is what matters – how much do the tornadoes affect you? In the end it doesn’t even matter how many tornadoes you are getting when the impact they are having is in permanent decline.
It doesn’t matter if glaciers are melting if the sea level isn’t rising
It doesn’t matter if the air temperature appears higher if the crops keep on growing faster.

Caleb
May 27, 2011 2:34 am

RE: Jake says:
May 27, 2011 at 12:28 am
Does the shown graph, outdated as you say, go through 2005 or 2010? Hard to tell.
It goes through 2007.

P. Solar
May 27, 2011 2:45 am

Scott Bixler says:
May 27, 2011 at 12:09 am

Sadly, my Geography 5 teacher at Santa Monica College is going to pin the increase in deadly tornadoes on climate change and the increase of water temperature of 2 deg. C in the Gulf of Mexico. I should bring this article to class and show then climate change has nothing to do with the increase of the current tornado outbreak. She also doesn’t want to admit that volcanoes contribute to global cooling. Go figure.

I’m actually starting to doubt this myself, if you are referring to any long term permanent impact.
The short term signal seems quite clearly present for major events but only lasts a few years. Now if you look at *rate of temp change* which is where you will see the effect of a “forcing” (but which few people do ), you will see a negative spike , ie temp dropping followed by temp rising.
This does not match the idea of a heavy permanent drop as seen in GISS-E for example.
Hansen et al are using exaggerated volcano forcing producing a permanent drop in temperatures to have an excuse for an exaggerated CO2 to pump it back up again.
If they stopped playing games with volcanoes they would probably find their models only needed something like the *real* calculated CO2 forcing “based on the science” rather than their fictional sensitivity.

P. Solar
May 27, 2011 2:48 am

Anthony, using death rate a climate indicator is pretty open to criticism. One obvious comment is that better predicition, warning systems and care of victims would be an important part of that downward trend.
If you want to comment on climate I would have thought climate parameters like force, frequency etc, would make the point more convincingly.

Michael Jankowski
May 27, 2011 3:08 am

I had someone try to tell me the other day that it was a “proven fact” that tornadoes were “getting larger and stronger every year.” Incredible.
There’s a list of the “official” worst-of-the-worst F5/EF5s from 1950 onward in the US at http://www.spc.noaa.gov/faq/tornado/f5torns.html – shows a nice downward trend.
By decade, it’s:
1950s – 17
1960s – 11
1970s – 14
1980s – 3
1990s – 10
2000s – 4
2010s – 4 so far (including Joplin)
Wikipedia lists some other “possible” F5/EF5s, which tallies up for the US to:
1950s – 21
1960s – 16
1970s – 14
1980s – 3
1990s – 12
2000s – 4
2010s – 4 so far

Les Johnson
May 27, 2011 3:11 am

Anthony: While not a tornado count, this site does track severe thunderstorm days in the US. Its updated daily.
http://www.spc.noaa.gov/exper/archive/events/index-eventdays-online.html
This site gives total tornadoes, but not broken out by severity.
http://www.ncdc.noaa.gov/sotc/tornadoes/2010/13

Matt
May 27, 2011 3:21 am

Wrong headline – there clearly IS a link between global warming and tornadoes. As it gets warmer, tornadoes get fewer.

Chris Wright
May 27, 2011 3:23 am

The first graph is curious. It shows an isolated spike in the seventies and there will be another one in 2011. But it doesn’t seem to match any obvious trend, almost as if these events come out of the blue. I’m reminded of a piece in WUWT afew weeks ago, about the appalling paper in Nature that claimed to establish a link between global warming and the terrible floods in England and Wales, in 2000. The people involved (I refuse to use the term ‘scientists’ in this connection) used an unending array of computer models to ‘prove’ the link. But, as Willis pointed out, if you actually look at the data you see a completely different picture. During the last century there was essentially no trend in the rainfall data, but there was an isolated spike in 2000. There was another, slightly larger, spike aropund 1930. Apparently there were two similar spikes in the 19th century.
There does seem to be a similarity between the flood spikes and the tornado spikes: they appear without warning and do not seem to be part of a trend – and certainly don’y correlate with climate change at all.
By chance, a couple of days ago I heppened to see the BBC Horizon program about freak waves. Amazingly, it appears that a ship is lost around the world every week, often with no obvious cause. Freak waves may be the answer. Ironically, according to the consensus view (the so-called ‘linear model’), freak waves are impossible – but now we know that freak waves do occur quite frequently – they are observed regularly by satelolits radars. The consensus turned out to be completely wrong – sound familiar?
Tornado outbreaks, flood disasters, freak waves: they all seem to appear out of the blue with no underlying trend. I wonder if there could be a deep, underlying connection?
Chris

ScuzzaMan
May 27, 2011 4:00 am

Yep, by end of next year tornadoes in the US will have given birth to 50 people …

tallbloke
May 27, 2011 4:21 am

Clearly death rates per million are down, which is testament to the improved warning technology, plus the skills and dedication of the National Weather Service and volunteer storm spotters
Could better housebuilding standards and storm shelters be helping too?

Tom in Florida
May 27, 2011 4:28 am

Matt says: (May 27, 2011 at 3:21 am)
“Wrong headline – there clearly IS a link between global warming and tornadoes. As it gets warmer, tornadoes get fewer.”
Exactly my thoughts, adding to the idea that warmer is better.

Craig S
May 27, 2011 4:49 am

Ian H says:
May 27, 2011 at 1:49 am
…..
According to this graph dead people who have not been killed by tornadoes should start popping up out of the ground any day now. Zombie invasion anyone?
…..
Shotgun? Check!
Axe? Check!
Armored V-8 Truck w/Nitro? Check!
I’m ready for the Zombie invasion, anyone else?

Wade
May 27, 2011 4:58 am

Chris Wright says:
May 27, 2011 at 3:23 am
Tornado outbreaks, flood disasters, freak waves: they all seem to appear out of the blue with no underlying trend. I wonder if there could be a deep, underlying connection?

The uptick in tornadoes was with warning. Joe Bastardi warned about it many months ago. Like it or not, the earth is now entering a cool phase. Also, there was a lot of snow in the northern US this past winter. When snow is on the ground, nights are colder. So all that snow provides more cold air. Tornadoes are formed with warm and cool air mix. Obviously it is more complex than that, but there is a reason why spring and autumn are tornado season and not summer or winter. This was not a freak wave. A little common weather sense was all that is needed to know this was going to be a bad tornado year.

Jason Calley
May 27, 2011 5:08 am

P. Solar says: “Anthony, using death rate as a climate indicator is pretty open to criticism. — snip –If you want to comment on climate I would have thought climate parameters like force, frequency etc, would make the point more convincingly.”
Yes, good point. Basing tornado analysis on deaths per year leads to the following conclusion. With a continuing decline in deaths per year, we will soon reach a state where we have fewer than zero deaths per year. Anti-tornadoes, spinning backwards, will pass over cemeteries, open the graves and raise people from the dead.
🙂

MikeL
May 27, 2011 5:26 am

So let me get this straight.. global warming is the cause of extreme weather events (ie. the devastating tornadoes) here in the US this year. According to the alarmist scientists this year has about the same average temperature as last year and the year before that. Then how come the global warming of the previous years did not produce a similar number of extreme tornadoes?

polistra
May 27, 2011 5:27 am

I’d think cold from the north would be a more important variable than warmth from the south. The Gulf doesn’t change on a daily basis, but cold penetration does.
I’ve been trying to find annual temp lists for places like Bismarck, but can’t find them. Does anyone have a good NOAA link to derive annual temp lists by season or by month for a city? Seems like that should be on the WUWT reference page in some form.
Might be relevant: the record low for today in Bismarck is -40 in 1974, the most recent mega-twister year.

Pull My Finger
May 27, 2011 5:53 am

Well according to McClatchey newspapers, (yea, I know, they are like the minor leagues as far as news services), it’s all global warming.

http://www.centredaily.com/2011/05/25/2736923/tornadoes-floods-droughts-scientists.html

Pull My Finger
May 27, 2011 5:54 am

-40 in MAY? That’s nuts.
I’ve noticed most of our local record highs in the spring date to the 30s and 40s.

May 27, 2011 6:03 am

Mr. Revkin says: “You can’t exclude climate change, but there’s simply no evidence through a half century of tornado history in the United States of a connection to warming.”
This sentence to me is a nonsense. The first part “You can’t exclude” means that you include it. The second part “simply no evidence” means the opposite. Except he left himself and out by using “climate change” in the first part and “warming” in the second.
Climate change maybe included if you count cooling.

May 27, 2011 6:12 am

Karymsky, Kizimen, Shiveluch in Kamchatka are now active regularly pluming high fliers. Kamchatka region has been active well above normal since 2008. Then the Iceland volcanic eruptions, Grimsvotn honking high altitude. Start a storm cellar installations company and you’ll do well over the next few years.

May 27, 2011 6:24 am

This link has context now. An astounding public display of emotional disconnectedness:
http://www.npr.org/blogs/13.7/2011/05/26/136676621/what-motivates-climate-change-deniers
A Quote: “I know what motivates my position [climate change causes tornadoes]: the sirens, the polar-bear pictures, the IPCC reports, fear for my grandchildren’s future. What motivates the denial?”
Er, Say again? Polar bear pictures?

Frank
May 27, 2011 6:26 am

Doesn’t everyone recognize that we have crossed a “tipping point” in 2010 and that now the number of strong tornados is going to skyrocket – just like it did in 2011. (:))

Douglas DC
May 27, 2011 6:37 am

It was 1975 that I reported a tornado in NE Oregon. seen by an FAA Flight Service station guy in Baker,Or. too. No one including the Pendelton Weather office believed us.
No kidding. If it happened now there would be evidence left -wrecked wind turbines…

Editor
May 27, 2011 6:40 am

That’s a down-trend, even though you’ve added 1 1/2 extra years to the last ‘decade’.

Les Johnson
May 27, 2011 6:42 am

Polistra: try this:
http://www.ncdc.noaa.gov/oa/climate/research/cag3/cag3.html
Click on “Cities”, then either cities in the list on the left, or on the map.
No Bismarck, but Dickinson ND is there.

Cyber
May 27, 2011 6:43 am

When I was flying back from Oakland California to get back to Joplin Monday morning (world’s shortest vacation to wine country that weekend), a lady at the airport said to me, upon hearing I was from Joplin, “You can’t tell me that these tornadoes aren’t caused by Global Warming.” And I said “They are caused by a strong Pacific ocean current effect from what I can tell, and there’s simply no evidence that a slightly warmer temperature would cause these storms.” She seemed genuinely shocked that I wasn’t prepared to blame the destruction in my town on other people’s SUVs I guess.

Pamela Gray
May 27, 2011 6:46 am

I wish it were the case that when warmers insist on linear trend lines, all other indices they wish to present must also be fitted with linear trend lines. Then they must use these lines to prove their mathematical case that global warming causes all these slanting up and slanting down statistics.

May 27, 2011 6:47 am

Bet we haven’t heard the last from Grímsvötn. Jön Frìmen, looking at the tremor signal doesn’t think so. Go to eruptions@bigthink and download the volcano app for android. It’s real cool, you have the location and all the info from the weekly volcanic activity reports (SMITHSONIAN) right there. You can practically see the temperature gradients sharpen from low altitude plumes near the equator and high altitude near the Arctic, or maybe it’s just me visualizing it.

Dave Springer
May 27, 2011 7:25 am

Any correlation between tornado frequency/intensity and solar magnetic or sunspot indexes?
Is it just coincidence that a near record high tornado year followed on the heels of a near record low sunspot year?
There’s actually some hypothetical basis to it. Tornadoes need clouds. Solar magnetic field is suspected of throttling cloud formation where a weak field allows greater cloud formation.
While it’s true that correlation is not causation a lack of correlation is pretty strong evidence of no causation. Correlation highlights things that deserve a closer look in regard to causation. Lack of correlation pretty much means “nothing going on here, move along now”.

May 27, 2011 7:26 am

Cyber,
You were much too nice to her. Kudos to you for being a nice guy. But I would have explained to her that “global warming” has amounted to only seven-tenths of a degree over 150 years, and that CO2 [“carbon” to the scientifically illiterate] is only 0.00039 of the atmosphere, and that $7 – $8 billion dollars is paid out every year by the federal government to ‘study global warming/climate change’, and while she was processing that new [to her] information, I would remind her that human nature being what it is, charlatans of all kinds have their snouts in the public trough.
That’s the long and the short of it. Money and power are the motivation, and honest science has nothing to do with the CAGW scam.

Kerry Eubanks
May 27, 2011 7:30 am

As many others have pointed out, fitting a linear trend to this kind of data doesn’t make sense. An exponential curve is more appropriate. Excel gave this result:
y = 377.59 * exp(-0.2642x) (R-squared = 0.8944)

Doug Proctor
May 27, 2011 7:48 am

Denying recent tornadoes are caused by Global Warming will probably provoke a backlash from the warmists that you don’t “care” about people. The association of unhappiness and climate change is a prime emotional motivator for the Gore-warmist. Technical relevance is trumped by tears and fears.

Robert Doyle
May 27, 2011 7:50 am

I must be dumb as a rock.
If warming was the trigger for tornadoes, then July & August would be the months
with the greatest number of these storms.
However, the storms peak late April to early June in most states.
Florida is a weather laboratory unto itself

May 27, 2011 8:01 am

Pat Michaels has an article at forbes.com that has some updated tornado numbers as well:
The Great Tornadoes Of 2011 Put In Perspective
-Chip

Kerry Eubanks
May 27, 2011 8:02 am

Sorry, I should have pointed out that the equation I gave a few posts earlier was for the death rate per million per year.

P Wilson
May 27, 2011 8:13 am

from the briefest of view of the graph going back to 1950-it looks like the average has decreased since the global warming scare of the early 1980’s onwards

Larry Hamlin
May 27, 2011 8:24 am

Excellent post. The L. A. Times ran a piece two days ago alleging to discuss the “science” of the recent tornadoes in the U.S. and after addressing the weather factors (warm Gulf of Mexico waters and a lower arctic jet stream) offered pure climate fear conjecture that global warming was creating more intense tornadoes. I wrote the reporter and pointed out that NOAA’s EF3-EF5 tornado tracking data from 1950 to the present completely debunked his opinion and that his biased observation had no business being addressed in a piece supposedly discussing the “science” of tornadoes. These climate fear alarmists will do doubt continue to try to make this tornado season akin to what they did to Hurricane Katrina and the 2005 Atlantic hurricane season. They are wrong on both counts.

May 27, 2011 8:32 am

More to come I think. Plenty of colder air in the mountains according to this report;
http://hosted.ap.org/dynamic/stories/U/US_MEMORIAL_DAY_SNOW?SITE=AP&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2011-05-27-04-51-12

pwl
May 27, 2011 8:36 am

No linkage? Tell that to these guys:
“It is almost impossible for us to pinpoint these specific events…and say they were caused by climate change,” says William Chamedies, an atmospheric scientist and dean of the Nicolas School of the Environment at Duke University. “On the other hand we do know that because of climate change those kinds of events will very, very likely become more common, more frequent, more intense. So what we can say is that these kinds of events that we are seeing are consistent with climate change. ”
http://www.voanews.com/english/news/usa/US-Extreme-Weather-Consistent-with-Climate-Change–122577569.html
How do they “know that because of climate change those kinds of events will very, very likely become more common, more frequent, more intense”?

pwl
May 27, 2011 8:39 am

Nullius in verba applies to you too William Chamedies and the Nicolas School of the Environment at Duke University, unless you believe you are exempt from the scientific method.
http://pathstoknowledge.net/2011/05/26/the-president-of-the-royal-society-wants-scientists-to-abandon-the-scientific-method.

David Falkner
May 27, 2011 8:44 am

I don’t know if you can compare death rates and tornado strength. It’s hard to imagine modern warning systems do not save lives and reduce the number of deaths in otherwise comparable storms.

pwl
May 27, 2011 8:57 am

If you believe you’re exempt from the scientific method you’re stating that you are not a scientist.

Leon Brozyna
May 27, 2011 9:06 am

Tragedies strike …
Scientists seek to understand.
And then there are those other critters that seek to cash in on tragedies for their own causes.

diogenes
May 27, 2011 9:19 am

Tamino has a nicely cherry-picked data set on his site. By just selecting the tornado records for each April over the last 60 years, he has managed to produce a hockey-stick! You could not make it up.

David Falkner
May 27, 2011 9:22 am

http://www.spc.noaa.gov/faq/tornado/killers.html
Plus, the number of deaths in a tornado season doesn’t automatically equate to the quantity of strong tornadoes in that season. You can see from the top 25 deadliest tornado list that 1953 has three of the top 25. The value for tornado strength in the first chart doesn’t show 1953 as an extraordinary year in the number of strong storms, but there is a good spike in the death rate.

Wondering Aloud
May 27, 2011 9:55 am

Darn now all those plans to claim that warming had so reduced cyclonic storms that tornadoes were a thing of the past are shot to heck.

ferd berple
May 27, 2011 9:59 am

Revkins graphs “Tornado Reports” appears misleading. The number of reports of Tornados is likely to go up as the number of people go up, which increases the chance that a Tornado that does no damage will be spotted.
This is supported by his graph itself which shows a decrease in F2-F5 tornados. So the increased number of reports must be due to more people reporting small tornados (F0-F1) which previously went unreported as they did no significant damage.
S0, what is being graphed is not an increase in damaging Tornados, which the graph shows are decreasing, but an increase in people reporting minor tornados.

CRS, Dr.P.H.
May 27, 2011 10:48 am

@P. Solar says:
May 27, 2011 at 2:48 am
Anthony, using death rate a climate indicator is pretty open to criticism. One obvious comment is that better predicition, warning systems and care of victims would be an important part of that downward trend.
—–
REPLY Exactly! Also, keep in mind the increased migration of the U.S. population towards urban centers and out of rural areas in the past 100 years or so. As we’ve built more sprawling suburbs & ex-urbs, we’ve given Mr./Mrs. Tornado quite a bit more of a population concentration to harass. I’d think that would have a direct impact on tornado-induced morbidity/mortality in recent years (1950’s onward).
Not to mention the invention of the mobile home, slab-built/stick-built tract housing etc. More/deadlier tornadoes? I doubt it, just a higher population at risk.

Chris D.
May 27, 2011 10:50 am

Re: what ferd berple says:
May 27, 2011 at 9:59 am
You need to click to the Dot Earth piece which has the following caption below the graph:
“Frequency of reports of strong (red) and weak (blue) tornadoes since 1950. Experts say the rise in weak tornadoes is from more reporting, not more storms. (NOAA/NSSL)”
It simply got left out when the graph got displayed here on WUWT.
Say what you will about Revkin, the admittedly few columns I’ve read of his seem fairly balanced, considering his audience.

Tom in Florida
May 27, 2011 10:54 am

Robert Doyle says: (May 27, 2011 at 7:50 am)
“I must be dumb as a rock.
If warming was the trigger for tornadoes, then July & August would be the months
with the greatest number of these storms.
However, the storms peak late April to early June in most states.
Florida is a weather laboratory unto itself”
Can’t disagree with your first line.
These storms are caused by contrasting air masses not warm weather. General warming would make for less contrast between air masses and thus less severe storms. So don’t be so eager to disparage rocks.

SteveSadlov
May 27, 2011 11:02 am

A secular global warming trend would tend to dampen the energy of the Spring jet stream, as the Semi Tropical Highs moved north earlier and earlier in the season. In the case of the current season, the opposite has been true. The Semi Tropical Highs are still “south for the winter” and are only just now starting to creep northward. That is indicative, if anything, of a secular global cooling trend.

May 27, 2011 12:11 pm

Michael Jankowski says:
I had someone try to tell me the other day that it was a “proven fact” that tornadoes were “getting larger and stronger every year.” Incredible.
And don’t bother sharing any REAL facts, right?
People’s power of self-delusion always amazes me.

James F. Evans
May 27, 2011 12:20 pm

Interstellar Bill says:
May 27, 2011 at 12:59 am
“The warmist fear-mongers shouldn’t be so eager to trumpet what are actually the results of global colding.”
This is my suspicion, too.
Normal, warm moist air from the Gulf of Mexico colliding with below normal cold air from the North.
See story of huge snow pack in the western states this Memorial Day weekend:
Heavy snows spoil weekend holiday plans in West, May 27, 2011
http://hosted.ap.org/dynamic/stories/U/US_MEMORIAL_DAY_SNOW?SITE=AP&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2011-05-27-04-51-12
Now, I’ll acknowledge that “warmer” than normal air could be coming from the Gulf of Mexico, but I haven’t seen any reports as such.
Or it could simply be a historical anomaly.

May 27, 2011 1:43 pm

I predict that tornadoes cause earthquakes. And if the world ever has another earthquake, I’ll consider that positive proof of my theory.
Yes, I will become a climatologist yet. 😉

Ross
May 27, 2011 3:49 pm

We have had all sorts of large weather events recently that look like events in 1974/75.
The big floods in Queensland (Australia) were comparable with 1974 , these tornados in the US, the last time the flood control gates were opened on the lower Mississippi R was in 1974 etc etc. What else happened in 1974 ? Wasn’t there a strong La Nina event ? I’m sure others can add to the list.
But I’m just an amateur who stands to be corrected if wrong.

SteveSadlov
May 27, 2011 4:37 pm

I was just checking out the web cams for Squaw Valley. White out conditions at present. Those going to enjoy the last weekend will be in for a powder day tomorrow.
They could go for at least another month if they wanted to, the lift towers are at minimum safe ground clearances in a number of high accumulation places. I think it’s an insurance thing, they buy insurance futures early in the season, if they want to top up later it’s very expensive. With a minimal ad budget they can’t afford to advertise this late in the season, most flatlanders have no clue it’s still snowing in the high country.

Dave
May 27, 2011 6:10 pm

“The Cascades blocked any of those warm, moist, refreshing Pacific breezes, harvesting their moisture to carpet ski areas for dewy-skinned Seattleites, and diverting what remained north to Vancouver or south to Portland. Consequently the Palouse had to get its air shipped down in bulk from the Yukon and British Columbia. It flowed across the blasted volcanic scab land of central Washington in […] a more or less continuous laminar sheet that, when it hit the rolling Palouse country, ramified into a vast system of floods, rivers and rivulets diverging around the bald swelling hills and recombining in the sere declivities. But it never recombined exactly the way it was before. The hills had thrown entropy into the system. Like a handful of nickels in a batch of bread dough this could be kneaded from place to place but never removed. The entropy manifested itself as swirls and violent gusts and ephemeral vortices. ”
Neal Stephenson quotes are always worth posting. A beautiful description of why tornadoes.

rbateman
May 27, 2011 7:26 pm

The NWS is heading to Durham, Calif, to assess the strength of the tornadoes that touched down in the area. Preliminary looks to be EF-2, one might even fetch and EF-3. Historians are searching records to see if something like it happened in the past.
What is unprecedented from what I see around the North State is the cold air that keeps right on pouring in. It’s coming from the N. Pacific, and it says volumes about what is going on out there. Every day this week I have looked out and seen snow stuck to trees up on the Trinity Alps. Mighty cold for end of May.

Spector
May 27, 2011 11:22 pm

I heard one comment on the news saying that these tornados were a consequence of the North Pacific Ocean water being abnormally cold this year, increasing the temperature contrast between air coming from the Pacific and air coming from the Gulf. Perhaps this is a delayed consequence of the unusual grand solar minimum of 2008-2010.
On KHB60, I heard a report this week from Stampede Pass (3672 ft) in Washington State that it was 32 degrees and snowing.

P. Solar
May 28, 2011 3:51 am

Kerry Eubanks says:
May 27, 2011 at 7:30 am
>>
As many others have pointed out, fitting a linear trend to this kind of data doesn’t make sense. An exponential curve is more appropriate. Excel gave this result:
y = 377.59 * exp(-0.2642x) (R-squared = 0.8944)
>>
Why is that any more “appropriate” ?
That shows that as we go back in time the number of deaths will tend to infinity. Far less credible than a straight line.
You’re just pulling an arbitrary equation out of the sack. It has no more validity than a straight line. (Which I agree is not a very suitable model.)

beng
May 28, 2011 5:53 am

No tornadoes here in western MD, but a series of rainstorms & T-storms. Massive stream flooding yesterday from 1.72″ rain in about 30 minutes. 60 mph winds & hail.
The last 11 days I’ve measured 8.2″ rain here. Rain-shadowing from the Appalachians doesn’t occur here when precip moves from the SE, S & SW instead of the west.

Brian H
May 28, 2011 11:33 am

Global Cooling Kills. One of the methods it uses is tornadoes. Be afraid! Be very afraid!

Michael Klein
May 28, 2011 10:09 pm

It is important to remember that the absence of evidence is not the evidence of absence. Global warming might increase the number of tornados in the future, but we can’t know for another 50 years. The question we should ask ourselves now is whether it is plausible that global warming could increase the number or severity of tornados.

May 29, 2011 6:35 am

Here is a copy of a post I made on Revkins website in response to his Tornado piece
Here is an excerpt from a Thirty Year Climate Forecast posted on my blog
climatesense-norpag.blogspot.com nearly one year ago which explains and anticipates the recent outbreak of Tornadoes.- the key item is the more meridional Jet Stream path on our cooling world in which the rising temperature trend peaked in 2003 and which has been cooling since then.
“Of particular note in climate forecasting is the negative phase of the PDO which began perhaps five years ago and may well last for another 25years. This suggests that La Ninas will be more frequent than El Ninos during this time span. A general earth cooling is thus more likely as was the case from 1940 to 1970 when similar conditions prevailed. Concurrent changes in the Arctic Oscillation suggest a pattern of meridional atmospheric flow will be more common than the more latitudinal flows of warmer periods.
Policymakers may wish to note the following possible effects on earth’s climate for the next 20 – 30 years. A cooler world with lower SSTs usually means a dryer world. Thus droughts will be more likely in for example east Africa with possible monsoon failures in India. In California the PDO will mean less rainfall with more forest fires in the south. However in the Cascades and Northern Sierras snowpack could increase since more of the rain could occur as snow. Northern Hemisphere growing seasons will be shorter with occasional early and late frosts and drought in the US corn belt and in Asia repeats of the harsh Mongolian and Chinese winters of 2009 – 10 . In Europe cold snowy winters and cool cloudy summers will be more frequent
There will be a steeper temperature gradient from the tropics to the poles so that violent thunderstorms with associated flooding and tornadoes will be more frequent in the USA, At the same time the jet stream will swing more sharply North – South thus local weather in the Northern hemisphere in particular will be generally more variable with occasional more northerly heat waves and more southerly unusually cold snaps. In the USA hurricanes may strike the east coast with greater frequency in summer and storm related blizzards more common in winter.”
In all modesty, although I say so myself, the forecast looks pretty good so far!!

JP
May 29, 2011 7:08 am

“Policymakers may wish to note the following possible effects on earth’s climate for the next 20 – 30 years. A cooler world with lower SSTs usually means a dryer world. Thus droughts will be more likely in for example east Africa with possible monsoon failures in India. In California the PDO will mean less rainfall with more forest fires in the south.”
Norman, I suppose Rivkin posted this prediction mainly assuming that less water vapor would be available due to generally cool temps. However, with a negative PDO, a number of things occur. The temperature differential between the equator and the poles increase. North Pacific storms become more frequent, and a general strenghtening of the Icelandic Low occurs. The NAO will also show an increase in the negative phase due to increase baroclinicity between the poles and the equator. For North America, this means more precip, more snow, and more severe thunderstorms.
For the subtropics, there may indeed be more droughts. But I don’t think there is enough daya out there that describes definite trends in the Walker and Hadley Cells in relation to the PDO. We do know that Austrailia suffers through heavy precip events during La Ninas. Much of East Africa is dependent upon changes in the Walker Cell (as is India). During El Ninos, India and East Afric can suffer through droughts (which also affects the Nile Delta). La Nina events would esseintially disrupt these droughts.

May 29, 2011 7:50 am

JP – I think you misunderstood the post somewhat.The prediction was mine not Revkins.
The specific response in any particular area to a generally cooling world would be highly variable in time and space and requires a really detailed analysis of the the interaction of all the various global pressure system at any particular time and for any particular place. The forecasts I made were meant to be very general – really only suggesting the sort of thing we may expect.You would need a very knowledgeable meteorologist like d’Aleo or Joe Bastardi to work out the details.

May 29, 2011 9:13 am

One further note- to those blaming the tornadoes on a warm GOM check the current situation at http://weather.unisys.com/surface/sst_anom.gif
The northern Gulf is up to 2degrees cooler than average.

Archwright
May 31, 2011 10:41 am

Lets compare the two, big destructive storm types Hurricanes and Tornadoes. Hurricanes are different, they are affected by several regional and global weather phenomena. El Niño/La Niña, winds across the Sahara desert, water temperatures, etc. Scientists know approximately how many Hurricanes will happen in a year by performing metrics on these natural phenomena.
The conditions that create tornadoes do not offer the same opportunity for long-term prediction. We know that sort of regional weather phenomena cause tornadoes. Scientists occasionally get a week before a burst of tornadoes in a region. Because the conditions that create tornadoes are on such a small scale (compared to the weather of the world at large), we have no science right now that connects global climate patterns to tornado generation.
So, attempting to connect Tornado occurrence to global climate is foolish.