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Comment by swagmoose | Hacker News Reader

"multiple storms have already spilled over into the hypothetical category 6"

If they do go this route, I'd like it if they future-proofed it and include categories 6-10. Seems inevitable we're gonna see the first category 7 in the next 5-10 years.

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Confusingly, the paper[0] cited by this article seems undecided on this front. Figure 1A of the paper puts Hurricane Patricia (2015) into hypothetical category 7, but the "current and proposed categories" in Table 1 stops at declaring category 6 wind speed > 86 m/s (or 192mph, 167 knots, 309 km/h), and category 7 doesn't make an appearance elsewhere in the paper.

I was really hoping to find an authoritative listing of the strongest storms, but it is missing in both the linked article and the underlying paper. The paper itself uses data from International Best Track Archive for Climate Stewardship, which has a confusing website. As a non-expert, the website's top windspeed[1] category lists the following storms with maximum wind speeds of >167 knots (category 6 in the proposed scheme):

    213kt - 1958 IDA
    194kt - 1958 GRACE, 1959 JOAN, 1959 DINAH, 1961 NANCY, 1964 SALLY
    185kt - 2015 PATRICIA
    184kt - 1961 VIOLET
    180kt - 1955 RUTH
    178kt - 1955 JANET,
    174kt - 1951 MARGE, 1953 NINA, 1956 WANDA, 1957 VIRGINIA, 1957 HESTER, 1957 KIT, 1957 LOLA, 1959 VERA, 1959 CHARLOTTE, 1966 KIT
    170kt - 1964 OPAL, 2013 HAIYAN, 2016 MERANTI, 2020 GONI, 2021 SURIGAE

I don't see any explanation for why there were so many fantastically powerful storms in the 1950s-60s. Perhaps the older data is of dubious quality?

[0] https://www.pnas.org/doi/full/10.1073/pnas.2308901121#t01

[1] https://ncics.org/ibtracs/index.php?name=browse-wind#210

There is some research regarding an increase in Saharan dust storms that retards hurricane development in the Eastern Atlantic. Apparently this is still trending upwards and has resulted in fewer hurricanes forming over the last few decades.

Wikipedia gives Typhoon Ida (not to be confused with various hurricanes named Ida) a wind speed of "only" 175 knots (325 kph; 202 mph) which accounts for the largest outlier in the list.

https://en.wikipedia.org/wiki/Typhoon_Ida_(1958)

Confusingly, that wikipedia page cites the same IBTrACS system that I referred to, and in that page[0] the max intensity is listed at 213 knots. The data shows that the 213 knot speed was seen for measurements across twelve hours on 1958-09-24.

[0] https://ncics.org/ibtracs/index.php?name=v04r00-1958263N1314...

You are looking at the data for the CMA (China Meteorological Agency). The official data center for the Western Pacific according to the World Meteorological Agency is the Japan Meteorological Agency (JMA/Tokyo), but the IBTrACS dataset does not have wind speeds from them for 1958.

The Wikipedia article is sourcing data from the JTWC (Joint Typhoon Warning Center), the US wind column for 1-minute sustained wind speeds. In general, the Wikipedia convention is to include wind speed data from the JMA and JTWC when available.

The scale is somewhat arbitrary (plot the points) but category 7 would start somewhere around 225MPH. Highest ever recorded is 215MPH, so category 7 is worth having in reserve.

Ida/Kanogawa was 245 mph/213 knot peak.

https://ncics.org/ibtracs/index.php?name=v04r00-1958263N1314...

Saffir–Simpson is based on sustained, not peak.

While that is probably most sensible, it doesn't seem like a lot of fun. Instead, I recommend we call a new global conference, every few years, to discuss the addition of each individual natural number to the Saffir-Simpson scale.

That does sound fun! Is the idea to progress sequentially? or do we consider the proposal of 13 before 7 if there is enough support to do so?

Not necessarily because there may not be any difference between a wind speed of 350mph and 400mph wind in term of destructive power. Both may simply be able to strip the land bare and deliver the everything above it many miles away as well as temporarily moving parts of the sea miles inland.

By the time storms of 7+ come that level become commonplace, I doubt there will be people track and name them.

Set Category 10 at the speed of light, then work backwards...

Well that's easy. The meteorologists can remember that category number = 10 v' / c, where v' is the maximum median windspeed over a one hundred acre convex region, and all anyone else needs to know is that every storm is cat 0.

Why should we "create" categories. There should be an algorithm for determining level. Input 1000 miles an hour, you get a category.

Earthquakes don't have an upper limit. It's just a function of energy.

I seem to recall a video (perhaps KurzGesagt) that a magnitude 25 earthquake would overcome the binding energy of Earth - the planet would be in separate pieces. That definitely is an upper limit: when the "earth" in earthquake literally cannot take more.

Earthquakes are sort of naturally limited though. A 9.0 is going to be catastrophic no matter what, and while I’m not saying a 10 couldn’t happen it would probably be something like once in a billion year event.

10.0 is firmly in "if it happens nobody's gonna be around to care what it's designated" territory I think. There's a practical point at which the death tolls are going to be sufficiently high that the number probably shouldn't matter.

Though in tornadoes there definitely are EF-4 designated twisters that are hotly contested online as being truly EF-5; often that's down to where damage occurs in the lifetime of a tornado though and it being difficult to prove windspeeds when a system is moving through, e.g.: trailer park vs an industrial park.

I don't think it's quite as cut and dried as that. A 9.5 hit Chile about 60 years ago, and about 95% of the most directly hit town survived. Which is not to minimize it - there were thousands of fatalities - but it was human scale tragedy, not apocalypse.

An estimate of the upper limit of an earthquake is approximately 10. It's a function of max rock strength.

It’s actually a function of energy released. The earthquake can get bigger if the fault slip is larger. A magnitude 12 quake is technically possible but requires an entire hemisphere to slip 500 meters. There’s a really interesting paper that takes the moment magnitude scale to its logical extremes.

PDF warning: https://www.fujipress.jp/main/wp-content/themes/Fujipress/pd...

I seem to recall something about the asteroid that killed the dinosaurs producing a magnitude 11.

I wonder what the collision that produced the moon rated?

Well, as long as they are only doing those in papers!

With regard to hurricanes, we are an active participant in creating the level of need for new terminology.

Fair enough - something like rock strength and rupture length. Good paper. Thank you

Agree, need to do this properly. What's a fair cap in our solar system?

"Neptune’s winds are the fastest in the solar system, reaching 1,600 miles per hour!"

What category is that?

https://scijinks.gov/planetary-weather/#:~:text=Neptune%27s%....

I would guess that atmospheric pressure is going to matter a lot for the expected "damage", so it would not make sense in places where it's wildly different ?

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