ROGER PIELKE JR.: A new paper has just been published by Zhang and colleagues — Time trends in losses from major tornadoes in the United States — which updates and extends our 2013 analysis. They find: “[B]oth the severity of damage from individual events and the total annual losses from tornadoes are seen to have reduced over time.”
Their analysis confirms our earlier work: “[O]ur findings reiterate the results of Simmons et al. (2013) who emphasize the importance of normalizing loss data to draw adequate conclusions about the severity of natural hazards.” …Â
Zhang et al. also find that the strongest tornadoes have also declined appreciably since 1950. The figure below shows their presentation of trends in tornadoes of various intensities (with F1 the weakest and F5 the strongest). You can see that the incidence of tornadoes of F2 strength and stronger have decreased. In our 2013 analysis we found that ~90% of damage results from tornadoes of F2 strength or stronger.
https://rogerpielkejr.substack.com/p/trends-in-us-tornado-damage-and-incidence
Excerpts: In 2011, the United States experienced more than 500 deaths and over $30 billion in losses from tornadoes. As is now common, climate activists were quick to claim that the destructive tornadoes that year were due to climate change. The National Oceanic and Atmospheric Administration (NOAA) rejected such claims, advising:
[A]pplying a scientific process is essential if one is to overcome the lack of rigor inherent in attribution claims that are all too often based on mere coincidental associations.
The 2011 tornado season motivated us — Kevin Simmons, Daniel Sutter and I — to take a close look at trends in tornadoes and their impacts across the United States. The result was a peer-reviewed paper with the first comprehensive normalization of U.S. tornado losses, for 1950 to 2011.
Our results surprised even us — U.S. tornado damage and tornado incidence appeared to have decreased dramatically, contrary to conventional wisdom:
The analysis presented in this paper indicates that normalized tornado damage in the US from 1950 to 2011 declined in all three normalization methods applied (two are statistically significant one is not). The degree to which this decrease is the result of an actual decrease in the incidence of strong tornadoes is difficult to assess due to inconsistencies in reporting practices over time. However, an examination of trends within sub-periods of the dataset is suggestive that some part of the long-term decrease in losses may have a component related to actual changes in tornado behaviour. Further research is clearly needed to assess this suggestion.
…
A new paper has just been published by Zhang and colleagues — Time trends in losses from major tornadoes in the United States — which updates and extends our 2013 analysis. (Published in the journal Weather and Climate Extremes) They find:
[B]oth the severity of damage from individual events and the total annual losses from tornadoes are seen to have reduced over time.
Their analysis confirms our earlier work:
[O]ur findings reiterate the results of Simmons et al. (2013) who emphasize the importance of normalizing loss data to draw adequate conclusions about the severity of natural hazards
…
Compare their results with ours in the figure below, which I have just updated through 2022.
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In the 11 full years following our analysis, 9 of 11 have seen overall below average tornado incidence in the United States — 2023 will wind up slightly above average. There is simply no evidence to support claims that tornadoes are getting worse or causing more damage. In fact, the evidence indicates the opposite and peer-reviewed research is strongly in agreement.
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There is far more reporting of tornado damage than in the past. There are cellphone cameras and drones everywhere giving us pictures of tornado damage.
There are more people to see tornadoes
There are more ways to see tornadoes
There is more stuff for tornadoes to wreck
There is more media coverage of tornadoes
CO2 doesn’t have anything to do with it.
And so, unlike in so many other areas, NOAA should get high marks for issuing an adjusted tornado count instead of the raw.
In the top figure the years 2008 and 2011 are outliers, pulling the average upward excessively. What was going on in those years to create those numbers?
Weather?
Things like stagnant high pressures vary in location and intensity from year to year. They can have a large impact on the confluence of weather fronts capable of spawning tornadoes.
More contrast in temperatures would be a big factor.
For example:
33.2°F (0.6°C)
The winter season of 2007-2008 (December-February) was about average in the contiguous U.S.1. It was the 54th coolest winter on record in the 113 year period of record1. The average temperature was 33.2°F (0.6°C), which was 0.2°F (0.1°C) above the 20th Century mean1. It was the 18th wettest December-February in the 1895-2008 record1. Warmer-than-average temperatures were observed along the South, Southeast and Northeast, while winter temperatures were below normal in the East North Central, Southwest, and West regions2.
The 2010–11 North American winter was influenced by an ongoing La Niña, which resulted in winter storms and very cold temperatures across a large portion of the Continental United States, even as far south as the Texas Panhandle1. Notable events included a major blizzard that struck the Northeastern United States in late December with up to 2 feet (24 in) of snowfall and a significant tornado outbreak on New Year’s Eve in the Southern United States1. The most notable event was a historic blizzard that impacted areas from Oklahoma to Michigan in early February. The blizzard broke numerous snowfall records and was one of the few winter storms to rank as a Category 5 on the Regional Snowfall Index1.
Thise more people are also dispersed to mor locations around the county.
And I think probably the most important reason why we now “see” so many weak tornadoes is that Doppler coverage has also expanded greatly over time.
And all the same applies to hurricanes as well. How many of them that we see in current times would have never been known about 100 years ago?
All one has to do is look at the NOAA stats to see this is correct. The vast majority of tornadoes reported are EF-2 or less. The last EF-5 reported was in 2013!
The proportion this year is pretty much more par as it has been for the last decade.
on par
Is this map just for one year (2022)?
Yes, but it is a good example of a typical year in the last 10 years.
There is simply no evidence…
Don’t worry, they’ll make it up
How can tornadoes get worse – when they are created from 2 main things:
The heat of that dry air depends on the aridity/dryness of where it was created and as those places are already rock hard bone dry deserts, there’s no extra capacity there.
So the system is already ‘full’ and running at maximum ‘output’ – there is simply no room for any more tornadoes
Not sure No. 2 is quite correct. Many times it’s cold, dry, northern air that pushes under the wet, warm, southern air that generates the towering thunderstorms that, in turn, generate tornadoes.
Incorrect.
It’s a matter of a cold front colliding with a mass of warm humid air.
By the time you get to the mid-west and upper plains, the humidity is not coming from the Gulf.
It is interesting to compare tornado losses to hurricane losses. With landfalling hurricanes, the losses have generally increased substantially, mainly due to increasing development of the coastal areas where both wind speed and storm surge is highest. Hurricane Ian created the most losses in Florida history last year in inflation adjusted dollars – but then it landfalled one of the most densely developed sectors of the Florida coast and in areas dominated by older construction built long before current building codes were implemented. Having plenty of warning as we had with Ian didn’t seem to help any.
Tornadoes on the other hand are decreasing in both severity and in losses. It would be interesting to delve into why that is so but not with hurricanes.
The key changes are not with the hurricanes and tornadoes, neither of which show much change, but in the buildings themselves.
But the buildings are always being replaced and repaired. With modern regulations enforcing modern material and building practices.
When a tornado hits they need to be stronger to damage a building that has been built for an area that gets tornadoes.
The coast has three differences.
1) As land is very desirable there the cost of building on it increases and thus any damage at all is worth more in dollars, because of the regulatory hoops that must be jumped trough to do anything there.
2) As land is very desirable there every morsel of land that becomes available is built on. Meaning more buildings to be damaged.
3) As land is very desirable there the use of the land skews towards high prestige purposes. Hotels rather than motels. Luxury homes rather than squats. Pleasure gardens rather than agricultural land. So any hit hurts more.
Warnings serve to get people out of the way. Beyond boarding up the windows, there’s not much that can be done to protect houses in such a short time period.
Areas where tornadoes hit tends to be more rural. Either forested or agricultural. The population in those states is growing, but not as fast as coastal areas.
Also the people that do move in tend to concentrate in the cities. So long as one of these cities is not hit by a tornado, the population that is in the path of these tornadoes has not increased that much.
‘Shirley there is shum mishtake’ as Connery might say.
Here in blighty we suffered the horrendous effects of our first named storm of the season. Storm Agnes yesterday. Agnes was billed as a dangerous powerful damaging low pressure system, an ex hurricane no less. Definitely something to be concerned about, with a yellow warning issued by the very concerned Met. office.
Its arrival was due around midday Wednesday with concerns through to midday Thursday.
Well it was some memorable event down here in middle England, we were waiting for those 55 MPH winds with trepidation oh yes, great anxiety, I can tell you.
At about midday I am sure I saw a leaf flutter in the sweet chestnut tree we have in the garden while the hawthorn full height not a hedge didn’t even bother to acknowledge Agnes had arrived.
I felt a slight breeze as I walked down to my workshop late afternoon. As an ex seaman I ventured it must have been at least a force 1 gusting to force 2 on the old Beaufort scale.
The powers that be must be at a new low when they big up such a nothing event as Agnes. No doubt there was somewhere in a high mountain in North Wales where a tourist had the top of their latte blown off but other than that tragedy, nothing to report.
But did it tip over any plastic chairs… that is when the big damage occurs !.
Well I liked what it did to Burning Man.
“High mountain in North Wales”
Yep Capel Curig in Conwy experienced winds of up to 75mph (121km/h)
Here in NE Wales countryside we had some rain about 5.30 – 7pm but nothing excessive. The tall trees blew around a bit and the cat came in – and that was it 🙂
Should have added that the Capel Curig wind speed was the first thing mentioned on the early morning BBC weather reports!