’s Contrived “Record Cat5 Hurricanes” Statistic

September 3rd, 2019 by Roy W. Spencer, Ph. D.

About an hour ago I posted an objection to a article entitled: Hurricane Dorian Becomes the 5th Atlantic Category 5 in 4 Years. Then I deleted it. When I first read the article it appeared that the headline was what they were claiming was a record. If so, then it was wrong because the 1930s also had a stretch of 4 years with 5 Category 5 Atlantic hurricanes.

I had not heard about the claim until my interview on Tucker Carlson last evening (hosted by Martha McCallum):

But it turns out that (reading carefully) what they claim is a record (which appears so) is that we have now had a stretch of 4 consecutive years with at least one Cat5 hurricane.

I claim that is a contrived statistic.

Which is more significant in a “climate change” context: that in 1933-34 there were two Cat5 storms (both in 1933), or in 2018-2019 there were also two Cat5 storms, but one in each year? Because that what this boils down to.

I think those would be considered equal in a climate context. In statistics you can always find some insignificant way of slicing and dicing the data to make a certain time period look “unique”. The recent 11+ year period (2006-2016) with no major hurricane landfalls in the U.S. (an unprecedented event) was in my opinion less contrived of a statistic, but since it didn’t fit the global warming narrative, few people are aware of it.

If you think the claim is legitimate and related to climate change, let me ask you: Is global warming really spreading out Cat5 hurricanes across the years, so multiple ones don’t occur in the same year? Because that’s the only difference between the 1930s “record” and the current “record”.

The important thing is that the main conclusion as represented by the title of their article (Hurricane Dorian Becomes the 5th Atlantic Category 5 in 4 Years) does not represent a record. It also happened in the 1930s, as shown by the chart in their article.

29 Responses to “’s Contrived “Record Cat5 Hurricanes” Statistic”

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  1. Art Groot says:

    Atlantic Cat 5 hurricanes during the past century:
    1921-1940: 8
    1941-1960: 2
    1961-1980: 8
    1981-2000: 4
    2001-2020: 13
    (2019/2020 are not over yet)

  2. fonzie says:

    Dr. S., your climate faithful are eagerly awaiting this month’s temperature update. Can’t wait to see if cooler ocean surface temps(?) are finally being reflected in the temperatures of the lower troposphere. Glad to see (in the video on tucker) that you’ve recouped nicely from your ordeal with back surgery. As the ol’ saying goes, “that which doesn’t kill us makes us stronger“…

  3. David Appell says:

    How about recalculating the trend in Florida landfalling hurricanes, in your last post, but starting at 1950, when you claim global warming started becoming noticeable? Starting before that mixes eras.

    There’s also this graph in today’s NY Times showing the number of Category 4 & 5 Atlantic hurricanes is increasing:


    • There has indeed been an increase in Cat5s since the early 1900s, but I really don’t trust the Atlantic basin statistics before the early 1970s since we didn’t have satellites. The Atlantic is a big ocean and highest sustained winds cover a small area and ships (obviously) avoided hurricanes as much as they could.

      I don’t think there is a “normal” for hurricane activity. The proxy evidence that landfalling Cat4-5 storms in the northeastern Gulf were considerably more frequent 1,000-3,000 years ago than in the last 1,000 years suggests huge natural variability:

      (If you are wondering why I trust this proxy evidence and not Michael Mann’s, the hurricane researchers didn’t have to “hide the decline”. They see the evidence of recent major hurricanes in the overwash sediments in coastal lakes. Mann could’t even see the recent warming in the tree ring data, the proxy data suggested cooling.)

      • Ric Werme says:

        I don’t have time to dig up details at the moment (it _is_ a work day, after all), but one thing people could do in pre-satellite days is look for large swells generated by distant hurricanes.

        That would certainly miss many of the ephemeral tropical storms that get named today, but at least it gave some indication where you didn’t want to take your cargo ship!

        Chris Landsea may have looked for a lot of those records in his reconstructions.

  4. JDHuffman says:

    “I claim that is a contrived statistic.”

    AKA, “torturing the data”, a relevant phrase I’ve seen you use before.

  5. Arless McGee says:

    It is funny how you word things Dr.

    “less contrived”? lol

    “The recent 11+ year period (2006-2016) with no major hurricane landfalls in the U.S. ”

    a) ‘landfalls in the US’ is a baseless claim as over that same 11 year period there were 70 named hurricanes in the Atlantic which is ABOVE the average.

    Tell the public that it doesn’t matter how many hurricane hit land. Certainly the media think it’s a big deal when it happens, and is always indicative of climate change in their minds.

    b) of those there were 30 major +3 category hurricanes over that same period which is the very nearly average predicted amount.

    wow, average? Is that due to climate change, too?

    So your claim is baseless and isn’t ‘less contrived’, it is fully contrived.

    also c) 2006 to 2016 in 11 years, not 11+ years.

    11+ can mean greater than 11 but less than 12. -Roy

    • AZ1971 says:

      a) Prior to satellites, we had relatively little information about hurricane intensity while out to sea in the Atlantic basin. Since shipping can move out of the way (and accounts for very little infrastructure and cost loss risk) using land-falling systems is most appropriate as a metric (i.e. we don’t live on the water.)
      b) ACE (accumulated cyclonic energy) of the Atlantic basin shows cyclical periodicity. No upwards trend of cyclone frequency or intensity is discernible.

      Your claim is baseless for a number of reasons, not the least of which is that AGW theory predicts every possible outcome regarding hurricane frequency and intensity, and thus cannot be falsified – meaning it fails to adhere to the scientific method.

    • Arless McGee says:

      I know you know this but the predicted ‘average’ of yearly hurricanes comes from the National Hurricane Center and has absolutely nothing to do with, afaik, ‘climate change’ as you insincerely replied.

      Regardless of your US landfall “less contrived” misnomer there will always have been 70 hurricanes, 30 major, in the Atlantic Basin during the time period you claim, which luckily for the US they did not affect too severely.

  6. Denny says:

    Hi Roy

    As I watched the TV coverage and the 175 mph wind speed for Dorian, I wondered at what altitude are those wind speeds taken today. 100 years ago those speeds could only have been calculated at the surface. Do they show wind speeds that are measured only at the surface?

  7. Denis Rushworth says:

    According to the graphics, the highest winds in a hurricane occur at an altitude of about 1,500 to 3,000 meters – about one to two miles. Winds at the surface are normally much less. At this moment, for example, (4 PM, EST) Dorian’s winds are in the 120’s or 130’s mph at the high altitudes while at 10 meters above the sea they are in the 70’s and 80’s mph.

  8. Ossqss says:

    So, how many Cat5 storms were not counted historically (say 1850 to 1940) as there was not a plane flying in them 24×7 or a satellite looking down on them with advanced sensors to catch that fleeting moment of strength? The subject itself is not a fair or verifiable one with such a lack of comparable data from tools/assets available today vs. the past.

    Would anyone have thought Patricia was as strong as it was without a plane in it?

  9. David says:

    I find it fascinating that last Thursday the forecast models predicted landfall over Florida by Sunday. Come Sunday most models changed to an eye over the water event with the potential for hitting the Carolinas. At the same time hurricane Dorian comes to a halt for two days off the Bahamas. None of the models or most/all hurricane forecasters saw this occurring. Add growing to a Cat 5. Since receding to a Cat 2.

    If in a three day time frame all the models and professionals can be wrong how can one correlate strength and frequency to a climatic event, w/ millions of factors at any moment in time contributing to all variances in a storms life, to the future hurricane events when just 70 years ago sattelite and aircraft technology were virtually non-existent. Comparing today w/ 100 years past, to predicting 30 years ahead seems like a level of conceit by man to a climate infinitely more complex than man can fathom.

  10. Stephen P Anderson says:

    That was a good interview. Dr. Spencer, ever consider debating Bill Nye? It seems like they always get someone on there who knows nothing about climate science. Bill Nye knows very little too but he is usually more confident or arrogant than the other guy.

  11. ren says:

    Dorian is now directed by jetstream to South Carolina.

  12. ren says:

    Hurricane Dorian may land in South Carolina. Will cause serious floods.

  13. ronnie says:

    On a related note:

    Dorian may actually be the only Atlantic hurricane of 2019 thus far (and we are half way through the season)

    Any reference to Tropical Storm Barry as a Cat.1 hurricane may be a ‘contrived’ claim.

    The evidence for Barry achieving hurricane status (sustained winds >74mph) is weak at best.

    • rah says:

      Well they gotta try and get their numbers somehow! They’ve named a couple of iffy storms this season also. Systems that 10 years ago would not have been given a name.

  14. Ossqss says:

    I believe in 2005, I think, the NHC stated they would get more aggressive on category calculations. So basically, they took the highest wind speed observed (could be from a T-storm), typically extrapolated from a plane or Sat, and used that for declaration of category, instead of the averaged area prior. Big differences came about from such moving forward. Did it create a trend? I would suspect the same took place with respect to Dorian @185.

    I am quite suprised we have not had more discussion on TCHP as part of these canes. There is another change in methodology that changes the language.

    Interestingly enough, the site now says they no longer provide version 1 data?

    “Maps created using this algorithm are no longer available on this website.”


    Try this.

    They no longer have the graphic showing how the shrinking glaciers made the Great Lakes over thousands of years.


    Here is the horrific graphic.

    Contrived is the operative word.

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